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DTC 244-Adaptive Learn Low (LPG)

1. 7 Is the replacement complete 7 SM20042002LPGDBW 149 Remove all test equipment except the System OK Go to OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 211 check for any stored codes Does the engine operate normally with no stored codes 150 SM20042002LPGDBW SM20042002LPGDBW 151 212 HO2S Open Inactive Sensor Sensor Ground PNK DK GRN To System Power Relay To Engine Ground Conditions for Setting the DTC Heated Oxygen Sensor Check condition Engine running _ Fault condition HO2S cold persistently more than 120 seconds e MIL On during active fault and for 1 second after active fault Adaptive Disabled during active fault Closed Loop Disabled during active fault Circuit Description The HO2S sensor is used to determine if the fuel flow to the engine is correct by measuring the oxygen content in the exhaust gas The ECM uses this information to correct the fuel flow with the Closed Loop multiplier and the Adaptive multiplier This fault will set if HO2S is cold non responsive or inactive for 120 seconds or longer 152 SM20042002LPGDB
2. Yes No Did you perform the On Board OBD System Go to Step Go to OBD Check 2 System Check Section e Key ON Engine OFF Go to Step Go to Step 3 4 e DST in Active Fault Mode Are any other DTC codes present with DTC 651 Go to step 4 Go to Step Go to Step 5 6 e Replace ECM with correct Service Part Go to Step Number 9 Is the replacement complete e Diagnose any other DTC codes before proceeding with this chart Have any other DTC codes been diagnosed and repaired 4 e Check the Service Part Number on the ECM to ensure correct calibration is in use Is the Service Part Number Correct e Check the mechanical operation of the throttle Is the mechanical operation of the throttle OK e Correct mechanical operation of the throttle Refer to Engine amp Component R amp R Section 1E Has the mechanical operation of the throttle been corrected e Check engine for large manifold vacuum leaks Refer to Fuel Systems Section 1B Symptom Diagnostics Did you find and correct the vacuum leak Go to Step Go to Step 8 7 Go to step 9 Go to Step Go to OBD 9 System Check Section SM20042002LPGDBW 245 DTC 653 Spark Rev Limit TPS 1 Signal Sensor Ground TPS 2 Signal 5 VOLTS Conditions for Setting the DTC Spark Rev Limit Check Condition Engine running Fault Condition Engine RPM greater than 4100 MIL On during active fault Adaptive Enabled Closed Loo
3. waren 18 E 48 BLUE PINK 18 A 24 BLUEWHITE 18 RE SL DXGREEN 18 R 52 ORANGE 18 ae 27 YELOWIS 5 2 UNUSED 3e sowie 3 UNUSED gt UNUSED UNUSED MD 6 LTGREEN RED 18 fron PED 12015798 CONNECTOR BLK LT GREEN 18 DKGREENJORANGE 18 PED 12099040 TERMINAL MALE PINK DK GREEN 16 2 MTRTWR4_EGO BLACKIE b PED_12176897 CONNECTOR PED 12048074 TERMINAL PED 12160490 LOCK DK GREEN WHITE 18 FEMALE C OIL PRESSURE a PUSH_ON_FEMALE BLACK 18 BLK LT GREEN 18 YELLOW 18 PINK DK GREEN 16 PED_1216 PED_1212 GRAY BROWN 20 PURPLE ORANGE 20 BLK LT GREEN 18 LT GREEN RED 18 PURPLE LT BLUE 18 TTBLUE DK BLUE 18 PINK WHITE 18 TAN ORANGE 18 AMP_1 967616 1 CONNEC 965906 5 TERMINAL 967067 1 SEAL 68 PED 12052643 CONNECTOR PED 12048074 TERMINAL PED 12052634 LOCK PED 12089442 SEAL CO10 WHITE RED 18 PED 12052641 CONNECTOR PED 12048074 TERMINAL PED 12052634 LOCK PED 12089442 SEAL WHITE BLACK 18 c014 ORANGE BLUE 16 PINK TAN 18 JA LOCKOFF wow BLACK LT GREEN 18 ECT EE 12162648 CONNECTOR 012124075 TERMINAL PED_12089340 TERMINAL MOTOROLA TMAP GROUND saccis BLACK 16 BLACK 12 RED TAN 16 RED TAN 16 H maa 5 V
4. Remove all test equipment except the System OK Goto OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 142 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 143 DTC 143 Never Crank Synced At Start GRY BRN Crank CKP sensor PPL ORN 12 Conditions for setting the DTC Crankshaft Position sensor Check Condition Engine running Fault Condition 1 invalid crank re sync MIL On during active fault Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Circuit Description 144 The Crankshaft Position sensor is a magnetic transducer mounted on the engine block adjacent to a pulse wheel located on the crankshaft It determines crankshaft position by monitoring the pulse wheel The Crankshaft Position sensor is used to measure engine RPM and its signal is used to synchronize the ignition and fuel systems The ECM must see a valid Crankshaft position signal while running If no signal is present for 800ms or longer with rpm greater than 90 this fault will set SM20042002LPGDBW MENGE O 143 Never Crank Sync at Start Yes No
5. Power Derate level 1 Circuit Description 120 The Engine Coolant Temperature sensor is a thermistor temperature sensitive resistor located in the engine coolant The ECT Engine Coolant Temperature sensor that is located in the coolant near the thermostat The ECT is used for engine airflow calculation fuel enrichment ignition timing control to enable certain features and for engine protection The ECM provides a voltage divider circuit so when the sensor reading is cool the sensor reads higher voltage and lower when warm This fault will help protect the engine in the event of over temperature When the coolant exceeds 220 degrees F and engine RPM exceeds 500 this fault will set and Power Derate 1 will be enforced During this fault maximum throttle position is 5096 and the MIL light will turn on SM20042002LPGDBW ptg 123 ECT Higher Than Expected 1 Did you perform the On Board OBD Go to F Go to OBD System Check 2 System Check Section e Key On Go to Step Intermittent DST Diagnostic Scan Tool connected 3 problem System Data Mode Go to Warm Engine to normal operating Intermittent temperature then run the engine above section 500 rpm for 60 seconds Does DST display ECT temperature of 220 degrees F or greater with the engine running over 500 rpm Verify with a temperature gauge that the Repair Go to step engine coolant is over 220 degrees F Cooling 4 Does the temperature gauge i
6. Check Condition Cranking or Running Fault Condition MAP voltage less than 0 05 Throttle Position greater than 2 and engine RPM less than 7000 MIL On Adaptive Disabled for remainder of key on cycle Closed Loop Enabled Misc Fueling is based on RPM and TPS Limp Home Condition during this fault Circuit Description 128 The Manifold Absolute Pressure sensor is a pressure transducer connected to the intake manifold It is used to measure the pressure of air in the manifold prior to induction into the engine The pressure reading is used in conjunction with other inputs to determine the airflow rate to the engine which determines the fuel flow rate This fault will set when the MAP reading is lower than the sensor should normally produce When this fault is set the Adaptive Learn will be disabled for the remainder of the key on cycle and the MIL will be on SM20042002LPGDBW as PTO 82 MAP t 132 MAP Low Voltage Vatueis 0102912 Go DEB Go to Step 2 Go to OBD je Check Section Go to Step 3 Intermittent problem Go to Intermittent section Key OFF Go to Step 4 Go to step 8 Disconnect the TMAP sensor from the wiring harness Jumper the 5 volt reference pin C and MAP signal circuit pin D together Key ON Does the DST display MAP voltage of 4 5 volts or greater Did you Dict you perform 5 TBD System the On Board OBD System Check Key On Engine running e DSC Di
7. 1 j XK Inspect coolant hoses for cracks warsaw P P fx Engine ignitionsystem _ J J J Inspect Battery case for damage Jx Inspect battery cables Check all electrical connectors J Check ignition timing and adjust x Replace spark plugs J Jj Check spark plug wires o 1 x Fuel System Maintenance T Replace fuel fiter do o xj x Inspect lock offforleaks Jj Ensure lock off closing EX Test LPG Gas regulator pressure Check air induction system for leaks T j Jx Check manifold for vacuum leaks J J j Jx Check FTV electrical connection T T T Jx Check throttle shaft for sticking T T Jj Jx Check injector amp rails for leaks 1 x Annually or Bi annually in dusty environments Engine Exhaust System J J f Inspect exhaust manifold for leaks x Inspectexhaustpipingforleaks P T T J Jx Inspect catalyst inlet and outlet J Check HEGO sensor connector J j Jx The maintenance schedule represents manufacturers recommended maintenance interv
8. File Page Flash CommPort Plot Log Help xl BMS Font m uu Link error attempting reconnect Connected at 19200 bps ToggePage F8 _Toggk Test Cel F10 FauftAccess MIL System States DBW Variables Injector Injector on Injectorolf Coil Number Spark Coll Number lowside lowside Engine Speed 1401 rpm Run Mode Running TPS command 00 x firing order dwell ms fing order voltage voltage Manifold Pressure psia sri Mesa TPS position 01 X ipn i 02 14 0 Coolant Temperature 1850 degF _ FuelContolMode CLAcive FPP command 00 o VERA 2 of 15 Cylinder Head Temp 1850 de9F Govemorswitch state God FPP postion 00 3 Emm 3 o 145 Manifold Temperature 1075 degF Active govemor type i TPS1 voltage 0484 volts 4 o2f 15 Intake Air Temperature 106 7 deg F Active governor made Droop TPS2 voltage 4477 volts 5 oof oo Vbat 139 vots Brake inputlevel voltage 0442 volts 6 oo 00 May 137 vots tices JE FE FPP2 voltage 0000 volts Hour meter 2843 heus IVS voltage 5000 vols Cumulative stats 13 starts Closed Loop Digital input Voltages Diagnostic Modes EGO1 0592 vols Fuel select voltage 104 volts Spark kill Normal 7 Closed loop 1 Jesu pz Fuel pump voltage 138 vols Iri Normal Adaptive 1 Gov voltage 208 volts hd ub ambe Gov2 voltage 206 vols i d verspeed voltage 50 vots
9. U CK Secondary Test Port Cap Primary Test Port Fitting Retaining Pins Low Pressure Regulator LPR Pressure Trim Valve PTV Guard PTV Vapor Oulet Fitting Coolant Outlet Fitting PTV Mounting Bolts Figure 5 Low Pressure Regulator N CAUTION The LPR is an emission control device Components inside the regulator are specifical ly calibrated to meet the engine emissions re quirements and should never be disassembled or rebuilt If the LPR fails to operate replace with an OEM replacement part A CAUTION When servicing the regulator use caution to in sure the jet is replaced in the regulator Failure to install the jet may cause damage to the regu lator and cause fuel control and emission prob lems The process of pressure reduction within the regulator causes a refrigeration effect this re quires that the regulator be heated with engine coolant to prevent the regulator from freezing and fail to function properly The regulator is connected into the coolant system by hoses SM20042002LPGDBW connected to the engines coolant circuit The emission certified regulator contains an ori fice or jet in the outet side of the regulator to maintain the proper amount of coolant flow during regular operation The orifice is located between the inlet fitting and the housing of the regulator Air Fuel Mixer The air valve mixer is an air fuel metering device and is completely self contained The
10. 78 SM20042002LPGDBW INSTRUMENT PANEL CONNECTOR C018 Wm ouem VSW nom oom o some p po eemise mam Eos fe po ver 8 mern sn umewws 000 Womeme INSTRUMENT PANEL CONNECTOR C019 wm wie coor enor rn 6 mee A 00 E Pink Dk Green Relay Fused Power BE Orange Yellow Charge Indication DIE NL NN not used SM20042002LPGDBW 79 80 SM20042002LPGDBW SECTION 1 4 DIAGNOSTIC TROUBLE CODES SM20042002LPGDBW 81 DESCRIPTION OF ECM BASED DIAGNOSTICS DEFINITION OF TERMS Active Gov Mode AL AL Mult Analog Batt BP CHT CL CL Mult Closed Loop DBW DTC ECT ECM EGO Forced FPP HO2S IAT IVS Low Rev Limit MAP MAT MIL ms Open Loop Power Derate Level 1 Power Derate Level 2 PSIA RAM TPS 82 Speed is governed by one of two modes Isochronous which maintains an exact speed or Droop which allows speed to drop a predetermined amount based on current engine load Adaptive Learn Adaptive Learn Multiplier The adaptive learn multiplier is a correction to the fuel delivery which is expressed as a percentage 96 and stored in the ECM s RAM 0 to 5 volt or 0 to 12 volt signals Battery Voltage Barometric Pressure The pressure of the outside air Cylinder Head Temperature Closed Loop Closed Loop Multiplier The closed loop multiplier is a fast ac
11. Circuit Description The ECM has checks that must be satisfied each time an instruction is executed Several different things can happen within the microprocessor that will cause this fault The ECM will reset itself in the event this fault is set and the MIL will be on until the code is cleared During this active fault Power Derate level 2 will be enforced When this is enforced maximum throttle position will be 20 This is enforced until the fault is manually cleared 172 SM20042002LPGDBW DTC 511 COP Failure Did you perform the On Board OBD Go to OBD System Check 2 System Check Section Key On Engine Running Go to Step Intermittent DST Diagnostic Scan Tool connected in 3 problem System Data Mode Go to Clear system fault code Intermittent Does DTC 511 reset with the engine idling Sepen e Check all ECM power and ground Go to Step Repair the circuits Refer to power and ground 4 circuit as distribution in engine electrical section necessary Are the power and ground circuits Ok Refer to Wiring Repairs in Engine Electrical Replace ECM Go to Step Is the replacement complete 5 Remove all test equipment except the System OK Goto OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine
12. Connected at 19200 bps Connected Contra and insirumeniztion Specialists Ford Power Products ECM interface Coolant Temperature Intake Air Temperature System Variables Manifold Pressure 250 250 Enone Speed AE m 200 200 Min Governor Setpoint 1000 pm 5 ae Max Governor Setpoint 4500 rpm 100 100 50 50 Pulse width 432 ms WS 05 EGO 0844 volts 2605 EGO2 0452 vols 102 degF 77 degF Hour meter 12404 hours Cumulative starts 37 starts Foot Pedal Position Throttle Position 1 s jaj Battery Voltage System State 60 60 50 100 150 Run Mode Running 40 40 0 0 Power Mode AN pee 20 i E Fuel Type Gasoline 0 o W 138 vols Fuel Control Mode ClActive owe rwn Governor switch state Gov3 Active governor type Min Active governor mode Dep Dil pressure state OK Reading Sensor and Actuator Values Most applicable sensor and actuator values are displayed on the Gauges screen The display shows the value for sensors voltages and the sensor values in engineering units NOTE If a DTC for a sensor is current the engineering value for that sensor may be a default limp home value and the voltage value will be the actual sensor voltage Use the voltage value when performing diagnostics unless directed to do otherwise by the diagnostic chart SM20042002LPGDBW 87 GRAPHING AND DATA LOGGING EDIS ECI Serial Communications NE l8l x Ele Page Flash
13. a sensor with an idle validation switch Checks and cross checks are constantly conducted by the ECM to determine the validity of the signals The Idle Validation Switch IVS is a normally closed contact idle that opens the IVS circuit to the ECM when the pedal is depressed more than the idle position This fault will set if the IVS is off idle open and the FPP voltage is less than 0 880 volts During this fault Power Derate level 2 and the Low Rev Limit are enforced When these are enforced the maximum throttle position is 20 and the maximum engine speed is 1300 RPM These are enforced for the remainder of the key on cycle If the active fault is no longer present the MIL light will be on for the remainder of the key on cycle This is a reminder that the Power Derate and Low Rev Limits are still enforced 206 SM20042002LPGDBW DTC 614 FPP Lower Than IVS Limit Go to Step Go to OBD ren Section Go to Step 3 Intermittent problem Go to Intermittent section Repair the NEN to Step 6 circuit as necessary Refer to Wiring Repairs in Engine Electrical Did you perform the On Board OBD System Check Key ON Engine OFF e DST Diagnostic Scan Tool connected in System Data Mode Does the DST display IVS OFF IDLE with the pedal in the idle position Jumper IVS signal and IVS ground together at wire harness connector Key ON Disconnect ECM wire harness connector Using a DVOM check for continuity between
14. Go ic Go to OBD System Check Section e Check to be sure that the ECM Go to Step Repair the ground terminal G1 to engine ground 3 circuit as is clean and tight necessary Is terminal G1 clean and tight Refer to Wiring Repairs in Engine Electrical Key OFF Over 5 Go to Step Go to Step Disconnect the CKP sensor connector volts 4 11 Using a DVOM check for voltage output from the CKP sensor while cranking the engine Do you have voltage output Key OFF Go to Step Repair the 5 circuit as necessary Refer to Wiring Repairs in Engine Electrical n E you perform the On Board OBD System Check Disconnect ECM connector C001 Using a DVOM check for continuity between CKP connector pin A and ECM connector pin 11 Do you have continuity between them Repair the Go to Step circuit as 7 necessary Refer to Wiring Repairs in Engine Electrical e Inspect the CKP connector C011 pins for damage corrosion or contamination Did you find a problem Using a DVOM check for continuity Go to Step Repair the between CKP connector pin B and ECM 6 circuit as connector pin 12 necessary Do you have continuity between them Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 145 Inspect the ECM connector C001 pins 11 and 12 for damage corrosion or contamination Did you find a problem Repair the Go to step Circuit as 8 necessary Refer to Wiring Repairs in Engine Electrical Using a D
15. Go to Step Go to Step 8 7 Go to step 9 Go to Step Go to OBD 9 System Check Section SM20042002LPGDBW 247 DTC 721 Transmission Over Temperature ECM 5 volts Transmission Temperature Voltage To Transmission Temperature Switch Relay Circuit Conditions for Setting the DTC Check Condition Engine running Transmission Temperature High Fault Condition closed circuit voltage low MIL On during active fault Power Derate 2 Circuit Description The transmission temperature switch is used to communicate a high temperature condition to the ECM Transmission damage can occur if the transmission is operated at high temperature The ECM uses an analog voltage input with an internal 5 volt reference If the transmission temperature circuit is grounded the input voltage will be near zero If it is open the input will be near 5 volts The temperature switch is normally open and should close at 122C and remain closed until the temperature drops to 115C The fault will set if the switch becomes closed with the engine running for longer than 10 seconds Power derate 2 will be enforced to a maximum throttle position of 2096 Diagnostic Aids 248 Before performing any electrical diagnostics be sure to check the transmission fluid levels and cooling systems for proper operation Also verify that the truck is being operated to the manufactures specifications in regards to load speed and envir
16. Max Govern Speed Override Check Condition Engine Running Fault Condition Engine RPM greater than 3800 for 2 seconds continuously MIL On during active fault Adaptive Enabled Closed Loop Enabled Circuit description This fault will set anytime the engine RPM exceeds 3800 for 2 seconds or more continuously This speed overrides any higher max governor speeds programmed by the user This is to help prevent engine or equipment damage The MIL will be on during this active fault 240 SM20042002LPGDBW DTC 651 Max Govern Speed Override Step Action No Did you perform the On Board OBD System Go to Step Go to OBD Check 2 System Check Section e Key ON Engine OFF Go to Step 3 4 e DST in Active Fault Mode Are any other DTC codes present with DTC 651 Go to step 4 Go to Step Go to Step 5 6 e Replace ECM with correct Service Part Go to Step Number 9 Is the replacement complete e Diagnose any other DTC codes before proceeding with this chart Have any other DTC codes been diagnosed and repaired 4 e Check the Service Part Number on the ECM to ensure correct calibration is in use Is the Service Part Number Correct e Check the mechanical operation of the throttle Is the mechanical operation of the throttle OK e Correct mechanical operation of the throttle Refer to Engine amp Component R amp R Section 1E Has the mechanical operation of the throttle been corrected e Ch
17. Replace the low pressure regulator LPR Refer to Low Pressure Regulator Replacement Is the action complete Replace the mixer assembly Refer to Fuel Mixer Replacement Is the action complete Go to Step 26 System OK SM20042002LPGDBW 39 The fuel supply system is operating normally if a failure of the control solenoids is suspected Refer to Fuel Control System Diagnosis 1 Install the test plug in the LPR second ary chamber 2 If you were sent to this routine by an other diagnostic chart return to the previous diagnostic procedure Replace the lock off Refer to Low Pressure Lock off LPL Replacement Is the action complete Go to Step 26 Is the action complete 1 Disconnect all test equipment 2 Install the primary and secondary test port plugs 3 Start the engine 4 Using SNOOP or equivalent leak check the test port plugs System OK Is the action complete 40 SM20042002LPGDBW SM20042002LPGDBW SECTION 1B4 SYMPTOM DIAGNOSIS 41 Symptom Diagnosis Important Preliminary Checks Before Using This Section Before using this section you should have performed On Board Diagnostic Check and determined that 1 The Control Module and MIL Malfunction Indicator Lamp are operating correctly 2 There are no Diagnostic Trouble Codes DTCs stored or a DTC exists but without a MIL Several of the following symptom procedures call for a careful visual and physical check
18. System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 261 check for any stored codes Does the engine operate normally with no stored codes 168 SM20042002LPGDBW SM20042002LPGDBW 169 DTC 262 System Voltage High GROUND RED TAN RED TAN Conditions for Setting the DTC System Voltage to ECM Check Condition Cranking or Running Fault Condition Switched battery voltage at ECM greater than 18 volts for 3 seconds MIL On for active fault and for 5 seconds after active fault Adaptive Disabled for remainder of key on cycle Closed Loop Enabled Circuit Description 170 The battery voltage powers the ECM and must be measured to correctly operate injector drivers trim valves and ignition coils This fault will set if the ECM detects voltage greater than 18 volts for 3 seconds at anytime the engine is cranking or running The adaptive learn is disabled The ECM will shut down with internal protection if the system voltage exceeds 26 volts SM20042002LPGDBW DTC 262 System Voltage High Step Action Value s Yes Did perform the On Board OBD Syste
19. The visual and physical checks are very important The checks can lead to correcting a problem without further checks that may save valuable time LPG Fuel System Check Verify the customer complaint Locate the correct symptom table Check the items indicated under that symptom Operate the vehicle under the conditions the symptom occurs Verify HEGO switching between lean and rich IMPORTANT Normal HEGO switching indicates the LPG fuel system is in closed loop and operating correctly at that time If a scan tool is available take a snapshot under the condition that the symptom occurs Go to Engine Scan Tool Data List to verify normal sensor values and parameters 42 SM20042002LPGDBW Visual and Physical Checks SM20042002LPGDBW Check all ECM system fuses and circuit breakers Check the ECM ground for being clean tight and in its proper location Check the vacuum hoses for splits kinks and proper connections Check thoroughly for any type of leak or restriction Check for air leaks at all the mounting areas of the intake manifold sealing surfaces Check for proper installation of the mixer module assembly Check for air leaks at the mixer assembly Check the ignition wires for the following conditions Cracking Hardness Proper routing Carbon tracking Check the wiring for the following items Proper connections pinches or cuts The following symptom tables contain groups of possible causes for
20. Values Yes No Did you perform the On Board OBD Go to OBD System Check 2 System Check Section Key On Engine Running Go to Step Intermittent DST Diagnostic Scan Tool connected in 3 problem System Data Mode Go to Clear system fault code Intermittent Does DTC 555 reset with the engine idling eM e Check all ECM power and ground Go to Step Repair the circuits Refer to power and ground 4 circuit as distribution in engine electrical section necessary Are the power and ground circuits Ok Refer to Wiring Repairs in Engine Electrical Replace ECM Go to Step s the replacement complete 5 5 Remove all test equipment except the System OK Go to OBD DST System Check Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 556 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 195 DTC 611 FPP High Voltage 5 volts Sensor Ground Conditions for Setting the DTC 196 Foot Pedal Position Check Condition Key On Fault Condition FPP1 sensor voltage exceeds 4 8 MIL On during active fault Low Rev Limit enforced 1300 Forced Idle7
21. components with your finger or any tools Remember the connector that you are checking might be tied into a circuit that could be damaged by electrostatic discharge 3 When using a screwdriver or similar tool to disconnect a connector never let the tool come in contact with or come between the exposed terminals 4 Never jumper ground or use test equipment probes on any components or connectors unless specified in diagnosis When using test equipment always connect the ground lead SM20042002LPGDBW first Do not remove the solid state component from its protective packaging until you are ready to install the part Always touch the solid state components package to a ground before opening Solid state components can also be damaged if They are bumped or dropped They are laid on any metal work benches or components that operate electrically such as a TV radio or oscilloscope GLOSSARY OF TERMS Air Valve Vacuum AVV The vacuum signal taken from below the air valve assembly and above the throttle butterfly ADP Adaptive Digital Processor Air Fuel Ratio The amount of air and fuel in the air fuel mixture which enters the engine shown in a ratio Analog Voltmeter A meter that uses a needle to point to a value on a scale of numbers usually of the low impedance type used to measure voltage and resistance Aromatics Pertaining to or containing the six carbon ring characteristic of the benzene series Fo
22. 15 set and the MIL will be on until the code 15 cleared This fault should be erased after diagnosis by removing battery power It will not self erase During this active fault Power Derate level 2 will be enforced When this is enforced maximum throttle position will be 20 This is enforced until the fault is manually cleared SM20042002LPGDBW DTC 513 A D Loss Did you perform the On Board OBD Go to o Sio System Check 2 Key On Engine Running Go to Step DST Diagnostic Scan Tool connected in 3 probis System Data Mode A Intermittent Clear system fault code Section Does DTC 513 reset with the engine idling Check all ECM power and ground Go 1 Repair the circuits Refer to power and ground circuit as distribution in engine electrical section Necessary Are the power and ground circuits Ok Reter 8 Wiring Repairs in ABA Replace ECM Go i D Is the replacement complete Remove all test equipment except the es OK OBD DST System Check Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 513 check for any stored codes Does the engine normally with no stored codes SM20042002LPGDBW 177 DTC 514 RTI 1 Loss Microprocessor
23. 4 8 wiring harness and Jumper connector terminals A and B together Key On Does the DST display ECT voltage of 0 05 volts or less Replace ECT sensor Using a DVOM check the resistance See Go to Step Go to step between the two terminals of the ECT resistance 6 5 sensor and compare the resistance chart vs reading to the chart temperature Is the resistance value correct in the DTC 121 circuit description 14 Go to Step Is the replacement complete Inspect the ECT wire harness connector Repair the Go to Step terminals for damage corrosion or circuit as 7 contamination necessary Did you find a problem Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 113 Key OFF Repair the Intermittent Disconnect ECM wire harness connector circuit as problem Inspect ECM connector pins 31 and 49 necessary Go to for damage corrosion or contamination Refer to Intermittent Did you find a problem section Repairs in Engine Electrical Jumper the ECT signal pin A at the ECT Go to Step Go to Step connector to engine ground 12 Does DST display ECT voltage of 0 05 or Key OFF Go to Step Repair the Disconnect ECM wire harness connector circuit as Using a DVOM check for continuity necessary between ECT sensor ground pin B and Refer to ECM connector pin 49 Wiring Do you have continuity between them Repairs in Engine Electrical Inspect ECM connector pins 31 and 49 Repair the Go to Step for damage
24. 4 problem Does DST FPP voltage ever drop below 0 2 Go to Intermittent section Key OFF Repair the Go to Step Disconnect FPP sensor connector circuit as 5 Inspect connector and wire terminals for necessary damage corrosion or contamination Refer to Wiring A bl found ny problems foun Repairs in Engine Electrical e Key ON 5 0 Volts Go to Step Repair the e Using ADVOM check for voltage at the circuit as FPP sensor connector between 5 volt necessary reference pin A and FPP sensor ground Refer to Wiring Do you have voltage between them Repairs in Engine Electrical 6 e Replace FPP Sensor 18 Is the replacement complete Key OFF Go to Step Go to Step Disconnect FPP Sensor from wire 8 9 harness e Jumper 5 volt reference circuit pin A and FPP signal circuit pin C together e Key ON Does DST display FPP voltage of 4 8 volts or greater SM20042002LPGDBW 201 e Check FPP connector wire terminals for damage corrosion or contamination Any problems found Repair the Go to Step Circuit as 6 necessary Refer to Wiring Repairs in Engine Electrical Go to Step Go to Step 10 14 Go to Step Repair the 11 circuit as necessary Refer to Wiring Repairs in Engine Electrical e Probe FPP connector signal circuit pin C with a test light connected to battery voltage Does the DST display FPP voltage of 4 8 volts or greater Key OFF Disconnect ECM wire harness connecto
25. 6 s the replacement complete Remove all test equipment except the System OK Go to OBD DST System Check Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 532 check for any stored codes Does the vehicle engine normally with no stored codes SM20042002LPGDBW 189 Using DVOM check for Voltage between ECM harness wire LT GRN R pin 50 and engine ground Do you have voltage DTC 554 Gaseous Fuel Lo Rev Overun PNK WHT TAN ORN PPL LT BLU TPS 1 Signal BLK LT GRN Sensor Ground LT BLU DK BLU TPS 2 Signal LT GRN RED 5 VOLTS Conditions for Setting the DTC TPS or FPP Code set Check Condition Engine running in LPG mode Fault Condition unable to enforce low rev limit of 1300 to 1500 rpm MIL On during active fault Adaptive Enabled Closed Loop Enabled Engine Shut Down Circuit description This fault may set if the engine is running in the LPG fuel mode with one ore more codes relating to the throttle control system If the ECM has been commanded to enforce low rev limit and the governor control system is unable to achieve low rev limiting the engine will shut down Diagnostic Aids In the event of multiple DTC codes
26. Check the Magnetic pickup sensor RPM Fuel System Checks Important A closed LPG manual fuel shut off valve will create a no start condition Check for air intake system leakage between the mixer and the throttle body Verify proper operation of the low pressure lock off solenoids Verify proper operation of the fuel control solenoids Check the fuel system pressures Refer to the LPG Fuel System Diagnosis Check for proper mixer air valve operation 46 SM20042002LPGDBW Ignition System Checks Engine Mechanical Checks Exhaust System Checks SM20042002LPGDBW Note LPG being a gaseous fuel requires higher secondary ignition system voltages for the equivalent gasoline operating conditions Check for the proper ignition voltage output with J 26792 or the equivalent Verify that the spark plugs are correct for use with LPG R46TS Check the spark plugs for the following conditions Wet plugs Cracks Wear Improper gap Burned electrodes Heavy deposits Check for bare or shorted ignition wires Check for loose ignition coil connections at the coil Important The LPG Fuel system works on a fumigation principle of fuel introduction and is more sensitive to intake manifold leakage than the gasoline fuel supply system e Check for the following Vacuum leaks Improper valve timing Low compression Bent pushrods Worn rocker arms Broken or weak valve springs Worn camshaft lobes Check the exhaust system for a possib
27. Conditions for Setting the DTC 178 Engine Control Module Check Condition Key on Fault Condition Internal microprocessor error MIL On until code is cleared by technician Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Power Derate level 2 until fault is cleared manually Circuit Description The ECM runs checks that must be verified each time an instruction is executed Several different things can happen within the microprocessor that will cause this fault The ECM will reset itself in the event this fault 15 set and the MIL will be on until the code is cleared This fault should be erased after diagnosis by removing battery power It will not self erase During this active fault Power Derate level 2 will be enforced When this is enforced maximum throttle position will be 20 This is enforced until the fault is manually cleared SM20042002LPGDBW DTC 514 RTI 1 Loss Did you perform the On Board OBD Go to OBD System Check 2 System Check Section Key On Engine Running Go to Step Intermittent DST Diagnostic Scan Tool connected in 3 problem System Data Mode Go to Clear system fault code Intermittent Does DTC 514 reset with the engine idling Sepen e Check all ECM power and ground Go to Step Repair the circuits Refer to power and ground 4 circuit as distribution in engine electrical section necessary Are the power and ground circuits Ok Refer to Wiring Repairs i
28. FTV 22 Install fuel supply line to the mixer and re set clamp 23 Connect the FTV electrical connector 24 Connect the electronic throttle body electri cal connection 25 Connect the air inlet duct 26 Start engine 27 Start the vehicle and leak check the pro pane fuel system at each serviced fitting 28 Connect the diagnostic service tool and verify system is operating closed loop and no MIL light is present 257 MIXER REPLACEMENT Figure 3 Removal Procedure 1 Disconnect the negative battery cable 2 Remove the air intake duct 3 Remove the Throttle body assembly Refer to Throttle Body Assembly Replacement 4 Remove the four 4 screws in the throttle body to FTV adapter and retain 5 Remove and discard the mixer to FTV adapter O ring Installation Procedure Lightly Lubricate the o ring of the Mixer to FTV adapter before installing Cover Throttle body adapter opening to prevent debris from entering engine until reassembly 1 Install Mixer to FTV adapter and secure with the four 4 screws Tighten 9 Nem 80 Ib in 2 Install Throttle body Refer to Electronic Throttle Body Assembly Replacement Copper Sealin ECT Sensor Ge z FIGURE 4 ENGINE COOLANT TEMPERATURE SENSOR REPLACEMENT 258 Figure 4 1 Disconnect the ECT electrical connect 2 Remove ECT from the adapter do not re move the adapter 3 Remove the ECT and discard Installation Procedure If the ECT
29. Heavy deposits Check the Crankshaft Position CKP sensor Additional Check Check the ECM grounds for being clean tight and in their proper locations Check the generator output voltage Check the vacuum hoses for kinks or leaks Check Transmission 62 SM20042002LPGDBW SM20042002LPGDBW SECTION 1 2 WIRING SCHEMATICS 63 ON VEHICLE SERVICE WIRE HARNESS REPAIR The ECM PCM harness electrically connects the ECM PCM to the various solenoids electrically and sensors in vehicle engine and passenger compartment Wire harnesses should be replaced with proper part num ber harnesses When signal wires are spliced into a har ness use wire with high temperature insulation only With the low current and voltage levels found in the sys tem it is important that the best possible bond at all wire splices be made by soldering the splices as shown in Figure 1 Molded on connectors require complete replacement of the connector This means splicing a new connector as sembly into the harness Refer to Figure 1 for wiring diagrams CONNECTORS AND TERMINALS Use care when probing a connector or replacing termi nals in them It is possible to short between opposite terminals If this happens to the wrong terminal pair it is possible to damage certain components Always use TWISTED SHIELDED CABLE 1 REMOVE OUTER JACKET 2 UNWRAP ALUMINUM MYLAR TAPE DO NOT REMOVE MYLAR a 3 UNTWIST CONDUCTORS STRIP INS
30. IVS signal and engine ground Do you have continuity Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 614 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW Go to Step een EMEN E OK mM OBD System Check 207 DTC 631 TPS 1 Signal Voltage High LT GRN RED 5 volts e PPL LT BLUE 5 BLK LT GRN Sensor Ground Conditions for Setting the DTC Throttle Position Sensor 1 Check Condition Cranking or Running Fault Condition TPS sensor voltage exceeds 4 8 MIL On during active fault Power Derate 1 Low rev limit 1300 rpm Forced idle 700 rpm Circuit Description 208 The Electronic Throttle has two counter acting Throttle Position Sensors Two sensors are used for improved safety and redundancy The Throttle Position sensor uses a variable resistor to determine signal voltage based on throttle plate position and is connected to the throttle shaft Less opening results in lower voltage and greater opening in higher voltage The TPS value is used by the ECM to determine if the throttle is opening as commanded This fault
31. OBD System i Go to OBD Check 2 System Check Section 2 Key ON Engine OFF Go to Step Intermittent DST Diagnostic Scan Tool connected in 3 problem DBW Drive By Wire test mode Go to Depress Foot Pedal until theThrottle Intermittent Command is 63 68 section Is the TPS voltage less than 2 0 volts 3 Key OFF Go to Step Go to Step Disconnect wire harness connector from 4 8 5 Probe TPS 1 signal circuit with test light connected to battery voltage Key ON Is TPS voltage 4 0 volts or greater throttle Go to Step 11 Did you find a problem Has the object been removed 7 Replace throttle Is the replacement complete e Key OFF e Disconnect ECM wire harness connector e Using a DVOM check for continuity between throttle connector TPS 1 signal terminal and ECM TPS 1 signal terminal Go to Step 11 Go to Step Repair the 9 circuit as necessary Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 233 Do you have continuity between them e Check throttle connector terminals for Repair the Go to Step damage corrosion or contamination circuit as 7 Did you find a problem necessary Refer to Wiring Repairs in Engine Electrical Repair the Go to Step circuit as 10 necessary Refer to Wiring Repairs in Engine Electrical Go to step 11 e Using a DVOM check for continuity between throttle connector TPS 1 signal and engine ground Do you have continuity between
32. On Fault Condition Internal ECM memory access failure MIL On until fault is cleared Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Power Derate level 2 enforced Circuit Description 182 Random Access Memory is located within the microprocessor that can be read from or written to at any time The System Fault Codes and the Adaptive Learn Table are among the data stored in RAM This fault will set if the ECM detects a problem accessing or writing information to RAM This fault will not self erase and must be cleared manually SM20042002LPGDBW DTC 516 Ram Failure Did you perform the On Board OBD Go to OBD System Check 2 System Check Section Key On Engine Running Go to Step Intermittent DST Diagnostic Scan Tool connected in 3 problem System Data Mode Go to Clear system fault code Intermittent Does DTC 516 reset with the engine idling Sepen e Check all ECM power and ground Go to Step Repair the circuits Refer to power and ground 4 circuit as distribution in engine electrical section necessary Are the power and ground circuits Ok Refer to Wiring Repairs in Engine Electrical Replace ECM Go to Step Is the replacement complete 5 Remove all test equipment except the System OK Goto OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engin
33. RED 12 CO16 ALTERNATOR ORANGEJYELLOW 18 PINK DK GREEN 16 CO17 YAZAKI_7323 6224 40 CONN ENGINE CONTROL MODULE C001 2717 PC 52 25 DUCES COWIIECTOR 211 A 26 TOT LOCI Wa C AS z114 25 DODD ETMER 211 OC 25 1130 TERS 70 DEANGE ELUE TE 15 17 GREEN 1 A vie 11 ALN sea 73 _ LTCAHIE 3 1 iE FFF IAT ECT H REY z B EL bg T ELLA DEUE ELE 1 POWER GROUND Xi HaT POWER GOUE FTH a THE MOILT REF sia a un ED 42 nie GFA T BECWM 20 TREK 4 AN I i TABH EN u RECTAN 16 FLLIT PI MOAT STARTER LOCKOUT aera ei r 1 WHITE ELACK 1E FUELFL MF ran 12 PALETTE a TESI T Ir FEEAWHITE 15 5 TAN CHAMGE IE aS DE GEREHANWHITE 13 TACH BL a ALM MERE 2 FLIFFLETIK ELLE AUXDUTI FUEL SELECT AL AHAFUZ kz 15 WHITERED 14 44 ELUETIHETE 44 ELUE WHITE 1H 1 EEGFEEH IE 1 EE 1 Um gy 1 2 PE ELELE 4 5 SM20042002LPGDBW COMMUNICATION PORT CONNECTOR C002 wm wie coor Lt Green Red 5 Volt Ref Black Lt Green Analog Return OIL PRESSURE CONNECTOR C003 Ere A Lt Green Black Oil Pressure Switch SM20042002LPGDBW 71 HEATED OXYGEN SENSOR HEGO CONNECTOR C004 pe eme A Black Lt Green Analog Return Pink Dk Green Relay Fused Power pope FUEL TRIM
34. Repair the Disconnect ECM wire harness connector circuit as C001 necessary Key ON Refer to Using a DVOM check for voltage between id electronic throttle connector TPS 2 signal in Engine in 5 and engine ground P Ha Electrical Do you have voltage a test light connected to battery voltage Does the test light come on e Inspect the electronic throttle wire harness connector and terminals for damage corrosion or contamination Did you find a problem Go s EZ Go to Step 10 SM20042002LPGDBW 217 Repair the Go to Step circuit as 9 necessary Refer to Wiring Repairs in Engine Electrical Replace electronic throttle Go to Step i the replacement complete 11 Key OFF Go to Step Repair the Disconnect ECM connector 6 circuit as Using a DVOM check for continuity necessary between throttle connector sensor Refer to ground pin 2 and ECM connector sensor Wiring ground pin 49 Repairs Do have continuity between them in Engine Electrical Remove all test equipment except the System OK Go to OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 633 check for any stored codes Does the engine operate normally wit
35. Reset clamps 6 Start engine and check for leaks BALANCE LINE HOSE REPLACEMENT 1 Remove the clamp to the fitting at the mix er 2 Remove small hose to check valve Remove and retain check valve 4 Remove clamp at the LPR connection Installation Procedure A CAUTION Balance line hoses are specifically designed DO NOT use hose material or length other than the OEM specified parts DO NOT mix the hoses when reinstalling Install check valve in correct direction Arrow on check valve pointing toward mixer SM20042002LPGDBW 7 nstall hose clamps and set back on each hose 8 Reinstall the LPR hose end to the LPR fit ting and set clamp 9 Install Check valve and set clamp Directional part arrow pointing to mixer 10 Reinstall the small hose section and set clamps 11 Start engine and check for leaks PTV HOSE REPLACEMENT 1 Using a hose clamp pliers disconnect the clamps on the hose fitting at the mixer 2 Using a small screw driver push locking clip back on PTV connection 3 Remove the hose and discard Installation Procedure A CAUTION PTV hoses are specifically designed DO NOT use hose material or length other than the OEM specified parts 4 Install hose clamps and set back on the mixer hose end 5 Reinstall hose at the PTV and push lock in place 6 Reinstall hose at the mixer and set clamp 7 Start engine and check for leaks FTV HOSE REPLACEMENT 1 Using a small sc
36. Than Expected LT GRN R Conditions for Setting the DTC External 5V reference Check Condition Cranking with battery voltage greater than 8 volts or engine running Fault Condition 5V reference voltage higher than 5 4 volts MIL On during active fault and for 2 seconds after active fault Adaptive Disabled during active fault Closed Loop Enabled Circuit Description The External 5 Volt supply powers some of the sensors and other components in the system The accuracy of the 5 Volt supply is very important to the accuracy of the sensors and therefore control by the ECM The ECM to determine if they are overloaded shorted or otherwise out of specification monitors the 5 Volt supply This fault will set if the 5 Volt reference is above 5 4 volts 188 SM20042002LPGDBW DTC 532 External 5V Reference Higher Than Expected Go to Step 2 System Check Section 3 Key ON Engine running Go to Step 3 Intermittent DST Diagnostic Scan Tool connected in System Data Mode Go to Does DST display DTC 532 Intermittent section Check all ECM ground connections Go to Step 4 Repair the Refer to Engine electrical power and ground circuit as distribution necessary Are the ground connections Ok Refer to Wiring Repairs in Engine Electrical Key OFF Repair the Go to Step 5 Disconnect ECM connector circuit as Key ON necessary Refer to Wiring Repairs in Engine Electrical Replace ECM Go to Step
37. VALVE FTV CONNECTOR C005 We meme emm A Red White INJ 7 72 SM20042002LPGDBW TMAP CONNECTOR C006 eee A Black Lt Green Analog Return IAT Lt Green Red 5 Volt Reference COIL CONNECTOR 007 wie coor NN ase Peso as Black Lt Green Analog Return Gree Pink Dk Green Relay Fused Power SM20042002LPGDBW 73 MAGNETIC PICKUP CONNECTOR C008 Pee ee fm emi dE er j THROTTLE CONNECTOR C009 Wm ee Jm pomme paws 2 eemiees tt ie Purple Lt Blue TPS 1 Lt Blue Dk Blue TPS 2 74 SM20042002LPGDBW PRESSURE TRIM VALVE PTV CONNECTOR C010 Wm STARTER SOLENOID CONNECTOR 011 Wm win coor SM20042002LPGDBW 75 ENGINE COOLANT TEMPERATURE SENSOR ECT CONNECTOR C012 Wm Black Lt Green Analog Return FUEL LOCKOFF CONNECTOR CO13 Wincor Jm A White Black Fuel Lockoff 76 SM20042002LPGDBW BATTERY POSITIVE CONNECTOR C014 es Jee et Power BATTERY POSITIVE CONNECTOR C015 Wm Jee SM20042002LPGDBW 77 ALTERNATOR CONNECTOR C016 win coor mata ALTERNATOR CONNECTOR C017 eme m Pink Dk Green Power Relay R2 Orange Yellow Charge Indicator
38. adapter to the block is removed locate the brass washer and replace e If the ECT adapter is replaced with a new adapter remove the O ring supplied with the adapter before installing the brass sealing washer Apply liquid pipe sealant to the ECT 5 Install the ECT to the adapter and tighten to finger tight 6 Tighten to specification Tighten 1 to 2 turns after finger tight COOLANT HOSE REPLACEMENT 1 Drain coolant 2 Using hose clamp pliers disconnect both hose clamps on each hose 3 Remove the coolant inlet hose form each fitting 4 Remove the coolant outlet hose Installation Procedure A CAUTION Coolant hose are specifically designed DO NOT use hose material or length other than the OEM specified parts DO NOT mix the inlet or outlet hoses when re installing 1 Install hose clamps and set back on each hose 2 Reinstall the coolant inlet hose to each fit ting 3 Reinstall the coolant outlet hose to each fitting SM20042002LPGDBW 4 Reset clamps 5 Refill with coolant 6 Start engine and check for coolant leaks VAPOR HOSE REPLACEMENT 1 Using a hose clamp pliers disconnect both hose clamps 2 Remove the vapor hose form each fitting Installation Procedure Vapor supply hose is specifically designed DO NOT use hose material or length other than the OEM specified parts 3 Install hose clamps and set back on each hose 4 Reinstall the vapor hose to each fitting 5
39. air is much hotter than normal The most common cause of high inlet air temperature is a problem with the inlet air system Ensure that the air inlet is not obstructed modified or damaged nspect the air inlet system for cracks or breaks that may allow unwanted under hood air in to the air inlet system SM20042002LPGDBW DTC 113 IAT Higher Than Expected 1 Diagnostic Aids This fault will set when inlet air is much hotter than normal The most common cause of high inlet air temperature is a problem with the inlet air system Ensure that the air inlet is not obstructed modified or damaged Inspect the air inlet system for cracks or breaks that may allow unwanted under hood air in to the air inlet system Tf none of the above can be found Follow the diagnostic steps for DTC 112 IAT Low Voltage SM20042002LPGDBW 105 DTC 114 IAT Higher Than Expected 2 TMAP SENSOR Conditions for Setting the DTC e Intake Air Temperature e Check Condition Engine Running Fault Condition Intake Air Temperature greater than 210 degrees and engine RPM greater than1000 MIL On for active fault and for 15 seconds after active fault Adaptive Disabled during active fault Closed Loop Enabled Engine Shut Down Circuit Description The is a combined Intake Air Temperature and MAP Manifold Absolute Pressure sensor A temperature sensitive resistor is used in the TMAP located in the intake manifold of the engine It
40. and must be measured to correctly operate injector drivers fuel trim valves and ignition coils This fault will set if the ECM detects system voltage less than 9 0 for 5 seconds or longer while the alternator should be charging The adaptive learn is disabled 166 SM20042002LPGDBW DTC 261 System Voltage Low EIN _ Value s Yes No Did you perform the On Board OBD System Go p Wa Go to OBD Check System Check Section Intermittent Go to Step problem 3 Go to Engine Electrical Intermittent section Go p u Replace Battery Go gt Repair charging System js 5 Back probe ECM connector pins 22 and Repair ECM Go to Step 23 Ground 6 Measure voltage with DVOM between circuit Go each pin and engine ground to Power Is the voltage greater than 9 0 volts and Ground section in engine Electrical Key On Engine Running DST Diagnostic Scan Tool connected in System Data Mode Does DST display system voltage greater than 9 0 volts 3 Check battery condition Is it OK e Check charging system Is it Ok Repair ECM Go to step power circuit 7 Go to Power and Ground section in engine Electrical teo Back probe ECM connector pins 19 and 20 Measure voltage with DVOM between each pin and battery voltage Is the voltage greater than 9 0 volts Replace ECM Is the replacement complete SM20042002LPGDBW 167 Remove all test equipment except the System OK Go to OBD DST
41. are correct for use with LPG R46TS e Check the spark plugs Remove the plugs and inspect them for the following conditions Wet plugs Cracks Wear Improper gap Burned electrodes Heavy deposits e Check the ignition wires for the following items Cracking Hardness Proper connections Cooling System Checks e Check the engine thermostat for always being open or for the wrong heat range 58 SM20042002LPGDBW Additional Check Check the transmission shift pattern Refer to the OEM Transmission Controls section the Service Manual SM20042002LPGDBW Check for dragging brakes 59 Rough Unstable or Incorrect Idle Stalling DEFINITION The engine runs unevenly at idle If severe enough the engine or vehicle may shake The engine idle speed may vary in RPM Either condition may be severe enough to stall the engine Preliminary Check e Refer to mportant Preliminary Checks Sensor Checks e Check for silicon contamination from fuel or improperly used sealant The sensor will have a white powdery coating The sensor will result in a high but false signal voltage rich exhaust indication The ECM will reduce the amount of fuel delivered to the engine causing a severe driveability problem Check the Heated Exhaust Gas Oxygen Sensor HEGO performance Check the Temperature Manifold Absolute Pressure TMAP sensor response and accuracy Fuel System Checks Check for rich or lean symptom that causes the co
42. burns wear proper eye protection If liquid fuels continues to flow from the connections when loosened check to make sure the manual valve is fully closed 5 Slowly loosen the inlet fitting and disconnect 6 Loosen the hose clamp at the outlet hose fitting and remove the hose 7 Remove and retain the locking pin in the outlet fitting and remove the outlet fitting from the LPR 8 Disconnect PTV connection and disconnect the vacuum hose 9 Remove the two LPR mounting bolts and retain 10 Place a small receptacle in the engine compart ment 11 Rotate the LPR to 90 so that the outlet fitting is pointing down into the receptacle and drain the LPR 12 Inspect the secondary chamber for any large dried particles and remove 13 Remove the receptacle and reinstall the LPR with the two retaining bolts and tighten to specifi cations 14 Reinstall the outlet fitting and secure with the previously removed locking pin 15 Reconnect the PTV electrical connection push connector until lock Click pull on the connector to ensure it is locked connect the vacuum line 16 Reconnect the outlet hose and secure the hose SM20042002LPGDBW clamp 17 Reinstall the fuel inlet line and tighten connec tion to specification 18 Slowly open the manual service valve The fuel cylinder manual valve contains an Excess Flow Check Valve open the manual valve slowly to prevent activating the Excess Flow Check Va
43. corrosion or contamination circuit as 11 necessary Did you find a problem Refer to Repairs in Engine Electrical Replace ECM Go to Step s the replacement complete 14 Key OFF Go to Step Repair the Disconnect ECM wire harness connector circuit as Using A DVOM check for continuity necessary between ECT connector signal pin A and Refer to ECM connector terminal 31 Wiring Do you have continuity between them Repairs in Engine Electrical Inspect ECM connector pins 31 and 49 Repair the Go to Step for damage corrosion or contamination circuit as 11 Did you find a problem necessary Refer to Repairs in Engine Electrical 114 SM20042002LPGDBW Remove all test equipment except the System OK Go to OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 121 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 115 DTC 122 ECT Low Voltage YEL GRY Sensor Ground Conditions for Setting the DTC Engine Coolant Temperature Check Condition Engine Running Fault Condition ECT sensor voltage less than 0 05 MIL On during active fa
44. driver circuit fails open The system will also be lean if an injector fails in a closed manner Fuel Pressure Low fuel pressure faulty fuel injector or damaged fuel pump assembly can cause fuel system to run lean Exhaust Leaks If there is an exhaust leak outside air can be pulled into the exhaust and past the 02 sensor causing a false lean condition Fuel Quality Contaminated or spoiled fuel can cause the fuel system to be lean Ground Problem ECM grounds must be good battery or engine ground 158 SM20042002LPGDBW DTC 243 Adaptive Learn High LPG Step Action 7 Value No Perform the On Board OBD System Check Are any other DTCs present Visually and physically check the following items The air intake duct for being collapsed or restricted The air filter for being plugged The 25 sensor installed securely and the wire leads not contacting the exhaust manifold or ignition wires ECM grounds for being clean and tight Refer to Section 1C Engine Electrical Power and Ground Distribution Fuel System Diagnostics Refer to Section 1B Fuel System Diagnostics Was a repair made a o Se Go to Step 2 Diagnose any other DTC codes before proceeding with this chart Go A d to Step Have any other DTC codes been detected Go i Go to step 4 diagnosed and repaired Key ON Engine running Battery Go A Repair the Using a DVOM back probe the HO2S voltage circuit as sensor connector heater circuit pin C f
45. e Check TMAP mechanical connection for correct mounting or possible damage causing leakage Is the TMAP sensor mechanical connection Ok Key OFF Disconnect ECM connector and inspect terminals for damage corrosion or contamination Is the connection Ok Replace TMAP sensor Is the repair complete e Disconnect ECM connector and check for continuity between TMAP connector sensor ground pin A ECM sensor ground PIN 49 Do you have continuity between them Go to step Repair the 9 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to step 11 Go to Step 11 System OK 126 SM20042002LPGDBW Replace ECM Refer to ECM replacement in the Engine Controls Section Is the replacement complete Correct TMAP mechanical connection Has TMAP mechanical connection been corrected seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 131 check for any stored codes Does the engine operate normally with no stored codes Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 SM20042002LPGDBW 127 DTC 132 MAP Low Voltage TMAP SENSOR Conditions for Setting the DTC Manifold Absolute Pressure
46. each symptom The order of these procedures is not important If the scan tool readings do not indicate the problems then proceed in a logical order easiest to check or most likely to cause first 43 Intermittent DEFINITION The problem may or may not turn ON the Malfunction Indicator Lamp MIL or store a Diagnostic Trouble Code DTC Preliminary Checks Refer to Important Preliminary Checks Do not use the DTC tables If a fault is an intermittent the use of the DTC tables may result in the replacement of good parts Faulty Electrical Faulty electrical connections or wiring can cause most Connections or Wiring intermittent problems Check the suspected circuit for the following conditions Faulty fuse or circuit breaker Connectors poorly mated Terminals not fully seated in the connector backed out Terminals not properly formed or damaged Terminal to wires poorly connected Terminal tension insufficient Carefully remove all the connector terminals in the problem circuit in order to ensure the proper contact tension If necessary replace all the connector terminals in the problem circuit in order to ensure the proper contact tension Checking for poor terminal to wire connections requires removing the terminal from the connector body Operational Test If a visual and physical check does not locate the cause of the problem drive the vehicle with a scan tool When the problem occurs an abnormal voltage or scan reading
47. firing order dwellms firing order voltage voltage Manifold Pressure 1438 psia Fuel Type Gasoline TPS position 01 X 1 45 EN o 134 Coolant Temperature 1133 degF Fuel Control Mode Open Loop FPP command 00 X 2 4 25 2 or 134 Cylinder Head Temp 1133 degF Governor switch state Gov3 FPP position 00 3 000 3 o 134 Manifold Temperature 1133 degF Active govemor type Min 51 voltage 0489 volts EE 01 134 Intake Ait Temperature 816 degF Active governor mode Droop TPS2volage 4472 vols 5 oo 00 Vbat 128 volts Brake input level Open voltage 0 451 vols 00 00 y 125 vots cise aes FPP2 voltage 0 000 vols Hour meter 12658 hours IVS voltage 5000 volts Cumulative starts 39 starts Glosed Loop Control Digital input Vohages Diagnostic Modes EGO1 0 000 vols Fuel select voltage 104 vols Spark kill _ Nomal Closed loop 1 00 X Fuel pump voltage 00 volts Injector kill Normal 7 Adaptive 1 pcm Gov voltage 205 volts DBWitestmode Enabled 7 EGO2 ears a 5 vols 3 Overspeed voltage 50 vols Y Enabled t Data SnapShot SnapShot Closedoop 2 00 ase Base Custom Adaptive 2 m Oil pressure voltage 00 vols Definitions Definitions Definitions Jm EMPTY R IMAP Iun Im sec Emy Historic Faults Active Faults FPP_pct pm EMPTY Psm wP EMPTY CLEM ECT EMPTY eem maro EMPTY Vbat CL_BM1 EMPTY JPwavo usw e 4 bem Vbat Flight Data pet
48. first digit pausing then flashing the second digit pausing and then flashing the third digit There will be a long pause between codes For example a code 143 would be 90 SM20042002LPGDBW one flash followed by four flashes followed by three flashes The MIL will first display a 166 three times Code 166 indicates that the ECM based diagnostic routines are functioning Then any Diagnostic Trouble Codes stored in memory will display three times each The MIL will then start over with the code 166 If the vehicle is started while the diagnostic jumper is in place the MIL will flash rapidly Diagnostic Trouble Codes may be cleared from the system ECM memory by moving the ignition key to the OFF position and removing the F1 system battery fuse for at least 15 seconds Note This will erase all of the memory in the computer including the adaptive learn Diagnostic Communication Error The ECM 5 volt reference circuit powers the Spectrum diagnostic link cable In the event that the 5 volt reference signal is open or shorted to ground you will not be able to connect to the system If you are unable to connect follow the quick checks listed below Be sure you are using the correct password and latest software for the system you are connecting to Check the ECM system power and ground circuits Refer to DTC 261 for the power schematic Also check for 12 switched power at ECM pin 21 with the ignition key on Check for power at the DLC connec
49. fuel system causing lean fuel mixtures such as low fuel pressure faulty mixture control solenoid or damaged fuel mixer assembly Never solder HO2S wires For the correct repair procedure refer to Wiring Repairs in the Engine Electrical Section 148 SM20042002LPGDBW DTC 211 Closed Loop Multiplier High LPG Step Action Yes No Did you perform the On Board OBD System Go to Step Goto OBD Check 2 System Check Section Go to step Intermittent Key On Engine Running 3 problem DST Diagnostic Scan Tool connected in Go to System Data Mode Intermittent i section Run engine to full operating temperature and then idle for a minimum of 2 minutes Does DST display HO2S voltage fixed below 0 35 volts after 2 minutes of idle run time 3 Key OFF Repair the Go to Step Disconnect ECM connector circuit as 4 Disconnect HO2S wire harness connector necessary Using a high impedance DVOM check Refer to for continuity between HO2S connector Wiring i i f Repairs signal and engine ground in Edging Electrical Do you have continuity Using a high impedance DVOM check Repair the Go to Step for continuity between HO2S connector circuit as 5 signal pin B and HO2S connector sensor necessary ground pinA Refer to Do you have continuity between them Wiring Repairs in Engine Electrical e Refer to Diagnostic aids for DTC 211 Go to Step Did you check the diagnostic Aids for DTC 6 211
50. gauge or a manometer to the secondary test port of the low pressure regulator LPR Start the engine and allow it to reach operating temperature Does the engine start and run Verify that the LPG fuel tank has a minimum of 1 4 tank of fuel that the manual valve is open and the tank quick connect is fully engaged Go to Step 4 Does the vehicle have fuel Go to Step 5 Go to Step 8 With the engine idling observe the pressure reading for the LPR secondary pressure Does the fuel pressure fluctuate Go to Step Go to Step 6 rhythmically OUTSIDE the specified 25 SM20042002LPGDBW 35 1 Disconnect the PTV electrical connectors Note This action may cause a DTC to be set by the ECM 2 With the engine idling observe the pressure reading on the secondary test Goto Fiel port Control System Is the fuel pressure WITHIN the specified gt Go to Step 7 range Inspect the air intake stream between the mixer assembly and the throttle body for leaks Inspect the fuel hose connection between the LPR and mixer assembly for damage or leakage Inspect the vacuum hoses to the FTV solenoid Go to Step Go to Step 26 22 Was a problem found and corrected 1 Remove Air induction hose to the mixer 2 Observe the air valve for movement while the engine is cranking Note Movement of the air valve will be minimal at cranking speeds Does the air valve move when the engine is cranked Connect a wat
51. indicates the problem may be in that circuit Intermittent Malfunction The following components can cause intermittent MIL and no Indicator Lamp MIL DTC s Adefective relay Control Module driven solenoid or a switch that can cause electrical system interference Normally the problem will occur when the faulty component is operating The improper installation of electrical devices such as lights 2 way radios electric motors etc The ignition secondary voltage shorted to a ground The Malfunction Indicator Lamp MIL circuit or the Diagnostic Test Terminal intermittently shorted to ground The Control Module grounds 44 SM20042002LPGDBW Loss of DTC Memory To check for the loss of the DTC Memory 1 Disconnect the TMAP sensor 2 Idle the engine until the Malfunction Indicator Lamp illuminates The ECM should store a TMAP DTC The TMAP DTC should remain in the memory when the ignition is turned OFF If the TMAP DTC does not store and remain the ECM is faulty Additional Checks ed SM20042002LPGDBW 45 No Start Control Module Checks Ifa scan tool is available Check for proper communication with both the ECM Check the 3A inline fuse in the ECM battery power circuit Refer to Engine Controls Schematics Check battery power ignition power and ground circuits to the ECM Refer to Engine Control Schematics Verify voltage and or continuity for each circuit Sensor Checks Check the TMAP sensor
52. lightest hydro carbons produced during petroleum refining Octane level is 107 Low Rev Limit Secondary engine speed control only used to limit speed when throttle positioning is not maintaining desired speed LPG Liquified Petroleum Gas M85 A blend of gasoline and methanol consisting of 85 methanol and 15 gasoline Measurements of Pressure 1 PSI 2 06 Hg mercury 27 72 H2O water column At sea level atmospheric pres sure is 29 92 Hg Methanol Known as wood alcohol a light volatile flammable alcohol commonly made from natural gas Misfire Failure of the air fuel mixture to ignite during the power stroke Mixer Fuel introduction device that does not include a throttle plate MPFI Multi Point Fuel injection A fuel injection system that uses one injector per cylinder mounted on the engine to spray fuel near the intake valve area of combustion chamber MTBE Methyl Tertiary Butyl Ether Oxygenate add to gasoline to reduce harmful emissions and to improve the octane rating Multi fuel System A motor fuel system designed to operate on two different fuels such as LPG and gasoline Natural Gas A gas formed naturally from buried organic material composed of a mixture of hydrocarbons with meth ane CH4 being the dominant component NGV Natural Gas Vehicle Nox See Oxides of Nitrogen Octane Rating The measurement of the antiknock value of a motor fuel OEM Original Equipment Manufacturer the vehicle
53. mixer is an air valve design utilizing a relatively constant pressure drop to draw fuel into the mixer from cranking to full load The mixer is mounted in the air stream ahead of the throttle control device A CAUTION The air fuel mixer is an emission control device Components inside the mixer are specifically calibrated to meet the engines emissions re quirements and should never be disassembled or rebuilt If the mixer fails to operate replace 25 assembly FTV Adapter to Mixer O ring Seal Fuel Inlet Fitting Fuel Trim Valve Fuel Trim Mounting Bolts Valve FTV a 274 FTV Mounting Adapter Figure 6 Air Fuel Mixer with an OEM replacement part When the engine begins to crank it draws in air with the air valve covering the inlet negative pressure begins to build This negative pres sure signal is communicated to the top of the air valve chamber through four vacuum ports in the air valve assembly A pressure force imbalance begins to build across the air valve diaphragm between the air valve vacuum cham ber and the atmospheric pressure below the diaphragm The air valve vacuum spring is cali brated to generate from 101 6 mm 4 0 inches of water column at start to as high as 355 60 mm 14 0 inches of water column at full throttle The vacuum being created is referred to as Air Valve Vacuum AVV As the air valve vacuum reaches 101 6mm 4 0 inches of water column the air valve begins t
54. necessary Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 97 NB Key Off Go p gt Go 4 gt 3 Disconnect the TMAP sensor connector from the wiring and harness and jumper pins A and B together Key On Does the DST display IAT voltage of 0 1 volts or less E Check for continuity between TMAP sensor connector ground circuit pin A and ECM sensor ground circuit pin 49 Do you have continuity between them Repair the Go to step circuit as 10 necessary Refer to Wiring Repairs in Engine Electrical Go to step 11 Repair the Go to Step circuit as 5 necessary Refer to Wiring Repairs in Engine Electrical Replace ECM Refer to ECM replacement in the Engine Controls Section Is the replacement complete e Re check wire harness and TMAP sensor connectors for damage corrosion or contamination Were any problems found System OK Go to OBD System Check Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 111 check for any stored codes Does the engine operate normally with no stored codes e Re check wire harness and TMAP sensor Repair the Go to Ste
55. operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 635 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 227 DTC 636 TPS1 Lower Than TPS2 TPS 1 Signal Sensor Ground TPS 2 Signal 5 VOLTS Conditions for Setting the DTC Throttle Position Sensor 1 amp 2 Check Condition Key On Fault Condition TPS1 lower than TPS2 MIL On for remainder of key on cycle Power Derate 1 Low rev limit 1300 rpm Forced idle 700 rpm Circuit description 228 There are 2 Throttle Position Sensors located within the throttle which use variable resistors to determine signal voltage based on throttle plate position TPS1 will read low voltage when closed and TPS2 will read high voltage when closed The TPS1 and TPS2 percentages are calculated from these voltages Although the voltages are different the calculated values for the throttle position percentages should be very close to the same The TPS values are used by the ECM to determine if the throttle is opening as commanded This fault will set if TPS1 is 20 or more lower than TPS2 At this point the throttle is considered to be out of specification or there is a problem with the TPS signal circuit Power derate 1 will be enforced limiting the throttle to 5096 maximum Low rev limit and forced idle will also be enforced d
56. present in the ECM control system always work to resolve the lowest numerical DTC code first This code may have been set as a result of another throttle control system In the event this does 190 SM20042002LPGDBW DTC 554 Gaseous Fuel Flow Rev Limit Step Action Value s Yes No 1 Did you perform the On Board OBD System Go i A Go to OBD Check System 2 e Check for other DTC codes that may be Go j 22 a to Step stored in ECM memory Did you find other DTC codes stored in the ECM memory l i s Bu Section e Repair DCT codes starting with the lowest code first Have the other codes been diagnosed and repaired Follow the diagnostic chart recommendations for DTC 637 5 Remove all test equipment except the System OK NE to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 554 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 191 DTC 555 RTI 2 Loss Microprocessor Conditions for Setting the DTC Engine Control Module Check Condition Key on Fault Condition Internal microprocessor error MIL On until code is cleared by technici
57. results in lower voltage and greater opening in higher voltage The TPS value is used by the ECM to determine if the throttle is opening as commanded This fault will set if voltage is less than 0 2 volts at any operating condition while the engine is cranking or running Power derate 1 will be enforced limiting the throttle to 5096 maximum and low rev limit and forced idle will also be enforced during this fault SM20042002LPGDBW DTC 632 TPS 1 Signal Voltage Low Bp Amin Yes I Me Did you perform the On Board OBD Go to Step Go to OBD System Check 2 System Check Section Key ON Engine OFF Go to Step Go to Step DST Diagnostic Scan Tool connected 4 3 DBW Drive by Wire throttle test mode Does the DST display TPS 1 voltage of 0 2 volts or less with the throttle closed e Slowly depress Foot Pedal while observing TPS 1 Go to Step Intermittent BR 4 problem Does TPS 1 voltage ever fall below 0 2 volts Go to Intermittent section Key OFF Go to Step Go to Step Disconnect the TPS 1 electrical connector 7 5 Jumper the 5 volt reference circuit pin A and TPS 1 signal circuit pin C together at the throttle connector Key ON Does DST display TPS 1voltage of 4 0 volts or greater e Key OFF Go to Step Repair the e Disconnect ECM wire harness connector 6 circuit as Using a DVOM check continuity between TPS 1 necessary connector signal pin C and ECM connector TPS 1 Refer to signal pin 53 Wiring
58. ring before installation 5 Install FTV to the throttle body 6 Install the and two bolts 7 Tighten retaining bolts Tighten 9 Nem 80 Ib in Connect Fuel supply hose 99 255 Mixer assembly Fuel Inlet Fitting Fuel Trim Valve Fuel Trim Mounting Bolts FTV Adapter to Mixer O ring Seal FTV Mounting Adapter FTV to Mixer Mounting Screws Throttle body to FTV 77777777 Adapter O ring Seal Throttlebody to FTV Sealing Sleeve Bosch Electronic Throttlebody TMAP Mounting Screws Throttlebody to bone Manifold i d Adapter O ring j Z gt Sensor Seal 4 Throttlebody T d to Manifold Adapter Mounting Bolts 777 Manifold adapter to FTV 2 d adapter Figure 3 Mixer Assembly 9 Connect electrical connection 10 Start the vehicle 11 Connect the diagnostic service tool and verify the engine is operating in closed loop and no MIL light is present 256 SM20042002LPGDBW TEMPERATURE MANIFOLD ABSOLUTE PRESSURE TMAP Figure 3 Removal Procedure 1 Disconnect the TMAP electrical connector 2 Remove the two retaining bolts 3 Remove the TMAP Installation Procedure e Apply a small amount of O ring lubricant to the TMAP o ring before installation 4 Install the TMAP 5 Tighten retaining bolts Tighten 7 Nem 62 Ib in 6 Connect the electrical connection 7 Start engine THR
59. stream of the fuel system The TMAP provides the ECM with the temperature of the air charge entering the engine which the ECM utilizes to correct the air fuel ratio depending on the ambient air temperature the vehicle is operating in It also provides the ECM with the Manifold Absolute Pressure MAP which allows to the ECM to ee adjust fuel air ratio based on barometric pres sure as well provides the ECM with the load condition being introduce to the engine The TMAP is mounted to the throttle body to mani fold adapter Wheel Copper Sealin ECT Sensor ee z Manifold Adapter Figure 12 Temperature Manifold Absolute Figure 14 Engine Coolant Temperature Pressure TMAP sensor Sensor ECT Engine RPM Sensor Engine Coolant Tmeperature Sensor The ECM relies on a Magnetic sensor to count ECT l the revolutions of the crankshaft to determine The ECM receives a signal from the Engine the engine speed The Magnetic sensor is Coolant Temperature ECT sensor The ECM mounted to a bracket located directly above a will make correction to the air fuel ratio based timing whell which is machined with teeth to on the engine operating temperature The ECM trip the magnetic sensor The timing wheel is has also been programmed with default settings mounted to the front pulley of the engine which may result in a power reduction or shut down the engine in the event the engine over heats 30 SM20042002LPGDBW Output PTV OR FTV
60. the ignition switch OFF A WARNING Residual vapor pressure will be present in the fuel system Ensure the work area is well venti lated before disconnecting any fuel line PROPANE FUEL SYSTEM LEAK TEST A WARNING Never use an open flame of any type to check for propane fuel system leaks Always inspect the propane fuel system for leaks after performing service Check for leaks at the fittings of the serviced or replaced com ponent Use a commercially available liquid leak detector or an electronic leak detector When using both methods use the electronic leak de tector first to avoid contamination by the liquid leak detector 252 Retaing Bot Filter __ Housing Bulkhead Filter Base Figure 1 Fuel Filter PROPANE FUEL FILTER REPLACEMENT Figure 1 Removal Procedure 1 Relieve the propane fuel system pressure Refer to Propane Fuel System Pressure Relief 2 Disconnect the negative battery cable 3 Slow loosen the fuel inlet hose fitting to re lieve any residual fuel pressure 4 Remove the filter housing retaining bolt and sealing washer discard washer 5 Remove the filter housing from the bulk head filter base discard the filter and the sealing ring 6 Clean and inspect the filter base for any debris Installation Procedure Be sure to install new sealing washer and seals Do Not use Teflon tape on the pipe fittings use only a liquid pipe sealant 7 Install the housing
61. the mixer air valve for sticking or binding Check the mixer module assembly for proper installation and leakage Check the PTV and FTV Ignition System Checks Note LPG being a gaseous fuel requires higher secondary ignition system voltages for the equivalent gasoline operating conditions If a problem is reported on LPG and not gasoline do not discount the possibility of a LPG only ignition system failure and test the system accordingly Check for the proper ignition voltage output with J 26792 or the equivalent Verify that the spark plugs are correct for use with LPG R46TS Check for faulty spark plug wires Check for fouled spark plugs Additional Check Check for manifold vacuum or air induction system leaks Check the generator output voltage SM20042002LPGDBW 53 Backfire Checks DEFINITION The fuel ignites in the intake manifold or in the exhaust system making a loud popping noise Preliminary Check Refer to mportant Preliminary Checks Ignition System Checks Important LPG being a gaseous fuel requires higher secondary ignition system voltages for the equivalent gasoline operating conditions The ignition system must be maintained in peak condition to prevent backfire Check for the proper ignition coil output voltage using the spark tester J26792 or the equivalent Check the spark plug wires by connecting an ohmmeter to the ends of each wire in question If the meter reads over 3
62. to the tank utilizing a quick coupler The other end of the service line is connected to a bulkhead connector mounted on the equipment sheet metal This bulkhead connec tor allows for a safe means of passing through the equipments engine compartment sheet met al and into the engine compartment If a bulk head connector is used a pressure relief device is mounted in the service line or the connector itself to prevent over pressurization of the ser vice line The service line is made of high pres sure hose with special material or possibly tub ing which is friendly to the LPG fuel and should always be replaced with an OEM supplied part A CAUTION The bulkhead assembly should never be re moved and a service line run through the sheet metal Fuel Filter Propane fuel like all other motor fuels is sub ject to contamination from outside sources Refueling of the equipments tank and removal of the tank from the equipment can inadver tently introduce dirt and other foreign matter into the fuel system It is therefore necessary to filter the fuel prior to entering the fuel system components down stream of the tank An inline bulkhead fuel filter is utilized in the fuel system to remove the dirt and foreign matter from the fuel The filter is replaceable Maintenance of the filter is critical to proper operation of the fuel system and should be replaced as 23 Figure 3 Inline Fuel Filter defined in the Recommended Mainte
63. will set if voltage is above 4 8 volts at any operating condition while the engine is cranking or running Power derate 1 will be enforced limiting the throttle to 50 maximum Low rev limit and forced idle will also be enforced during this fault SM20042002LPGDBW DTC 632 TPS 1 Signal Voltage Low Did you perform the On Board OBD Go to OBD System Check 2 System Check Section Key ON Engine OFF Go to Step Goto Step DST Diagnostic Scan Tool connected in 4 3 DBW Drive by Wire throttle test mode Does the DST display TPS 1 voltage of 0 2 volts or less with the throttle closed Slowly depress Foot Pedal while Go to Step Intermittent observing TPS 1 voltage 4 problem Does TPS 1 voltage ever fall below 0 2 Go to f Intermittent section Key OFF Go to Step Go to Step Disconnect the TPS 1 electrical 7 5 connector Jumper the 5 volt reference circuit pin and TPS 1 signal circuit pin C together at the throttle connector Key ON Does DST display TPS 1voltage of 4 0 volts or greater Key OFF Go to Step Repair the Disconnect ECM wire harness connector 6 circuit as Using a DVOM check continuity between necessary TPS 1 connector signal pin C and ECM Refer to connector TPS 1 signal pin 53 Wiring Do have continuity between them Repairs in Engine Electrical Replace ECM Go to Step s the replacement complete 9 e Inspect the throttle wire harness Repair the Go to Step connector terminals for damage Circu
64. with the engine idling UN e Check all ECM power and ground Go to Step Repair the circuits Refer to power and ground 4 circuit as distribution in engine electrical section necessary Are the power and ground circuits Ok Refer to Wiring Repairs in Engine Electrical Replace ECM Go to Step Is the replacement complete 5 Remove all test equipment except the System OK Goto OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 512 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 175 DTC 513 A D Loss Microprocessor Conditions for Setting the DTC 176 Engine Control Module Check Condition Key on Fault Condition Internal microprocessor error MIL On until code is cleared by technician Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Power Derate level 2 until fault is cleared manually Circuit Description The ECM has checks that must be verified each time an instruction is executed Several different things can happen within the microprocessor that will cause this fault The ECM will reset itself in the event this fault
65. 0 adjust the tension Do not over tighten the tension of the belt Over tightening may cause overload on the bearings and pulleys of the drive belt components Serpentine Belt System Serpentine belts utilize a spring loaded tensioner which keeps the belt properly adjusted Serpentine belts should be checked according to the mainte nance schedule in this section The engine manufacturer does not recommend the use of belt dressing or anti slipping agents on either belt configuration Cooling System A WARNING It is important to remember that the cooling system of this engine be maintained properly to insure the longevity of the engine Maintenance of the cooling system is critical to not only the engine but the fuel system as well Because the LPG vaporizer is con nected into the cooling system low coolant levels and restricted or plugged radiator cores can impact the performance of the fuel system Therefore prop er maintenance of the cooling system should include removing dust dirt and debris from the radiator core on regular intervals To properly maintain the cooling system follow the recommend maintenance sched ule in this section Cooling system inspections should be performed as prescribed when inspecting the cooling system check for the following e Plugged or restricted radiator core clean with compressed air blow dust and debris from the core and the fan shroud Check the radiator cap to insure pro
66. 0 000 ohms replace the wires Check the connection at each ignition coil Check for deteriorated spark plug wire insulation Check the spark plugs The correct spark plugs for LPG are R46TS Remove the plugs and inspect them for the following conditions Wet plugs Cracks Wear Improper gap Burned electrodes Heavy deposits 54 SM20042002LPGDBW Engine Mechanical Check Important The LPG Fuel system works on a fumigation principle of fuel introduction and is more sensitive to intake manifold leakage than a gasoline fuel supply system e Check the engine for the following Improper valve timing Engine compression Manifold vacuum leaks Intake manifold gaskets Sticking or leaking valves Exhaust system leakage e Check the intake and exhaust system for casting flash or other restrictions Fuel System Checks e Perform a fuel system diagnosis Refer to LPG Fuel System Diagnosis SM20042002LPGDBW 55 Lack of Power Sluggishness or Sponginess DEFINITION The engine delivers less than expected power There is little or no increase in speed when partially applying the accelerator pedal Preliminary Checks Fuel System Checks Sensor Checks Exhaust System Checks 56 Refer to Important Preliminary Checks Refer to the LPG Fuel system OBD System Check Compare the customer s vehicle with a similar unit Make sure the customer has an actual problem Do not compare the power output of the vehicl
67. 00 rpm Power Derate 1 Circuit Description The Foot Pedal Position sensor uses a variable resistor to determine signal voltage based on pedal position Less depression of pedal results in lower voltage and greater depression results in higher voltage This fault will set if voltage is over 4 8 volts at any operating condition while the key is on If the voltage exceeds 4 8 then FPP is considered to be out of specifications At this point the ECM does not have a valid signal and must therefore enforce the low rev limit and Power Derate level 1 When these are enforced the maximum throttle position is 50 and the maximum engine speed is 1300 RPM The Low Rev Limit is enforced for the remainder of the key on cycle to 700 rpm Rev limit is still enforced if the active fault is no longer present SM20042002LPGDBW DTC 611 FPP Voltage s Did you perform the On Board OBD Go to T Go to ZEE System Check 2 System Check Section Key ON Engine OFF Go to Step Go to Step DST Diagnostic Scan Tool connected in 8 3 System Data Mode Does the DST display FPP voltage of 4 8 volts or greater with the foot pedal in the idle position Slowly increase FPP while observing FPP voltage Does DST FPP voltage ever exceed 4 8 volts Go to step Intermittent 4 problem Go to Intermittent section Repair the Go to Step circuit as 5 necessary Refer to Wiring Repairs in Engine Electrical Disconnect ECM connec
68. 21 5 BAR 312 psi LPG Fuel Tank disconnect coupling when applicable Sr Figure 2 Typical Propane Fuel Tank Propane is stored in the fuel tank as a liquid The approximate pressure of the fuel in the tank is 16 5 bar 240 psi when the tank is full at an ambient temperature of 27 C 81 F The boiling point temperature at which the liquid fuel becomes vapor is approximately 40 C 40 F When the fuel changes from liquid to vapor the fuel expands and creates pressure inside the tank When the tank service valve is opened the pressure inside the tank forces the liquid fuel out though the pick up tube located near the bottom of the fuel cylinder Because the propane is stored under pressure the tank is equipped with a safety valves which are normal ly set at 25 8 bar 375 psi to prevent tank rup ture due to over pressurization of the cylinder The service valve mounted in the end of the cylinder controls the flow of fuel from the tank SM20042002LPGDBW By turning the handle to its open position fuel flows out of the tank and into the service line The service valve is also equipped with a safety feature called an excess flow check valve This feature reduces the flow from the service valve in the event of a rupture of the fuel line or any down stream component Service Line Propane flows from the fuel tank to the electric lock via the service line The service line is connected
69. 2S sensor wire harness connector Disconnect ECM wire harness connector Key ON Using a DVOM check for voltage at HO2S connector signal pin B and engine ground Do you have voltage 5 Replace HO2S sensor Is the replacement complete m 4 Repair the Go gt circuit as necessary Refer to Wiring Repairs in Engine Electrical BN SM20042002LPGDBW 163 Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 244 check for any stored codes Does the engine operate normally with no stored codes 164 SM20042002LPGDBW SM20042002LPGDBW 165 DTC 261 System Voltage Low aa ECM 19 GROUND Bre 20 RED TAN 22 VBAT RED TAN 23 Conditions for Setting the DTC System Voltage to ECM Check Condition Key on and RPM greater than 1500 Fault Condition Battery voltage at ECM less than 9 0 volts continuously for 5 seconds MIL On for active fault and for 10 seconds after active fault Adaptive Disabled for remainder of key on cycle Closed Loop Enabled Circuit Description The battery voltage powers the ECM
70. 31 Intermittent section Key OFF Go to Step Go to Step Disconnect ECM connector 5 4 Using DVOM check for continuity between ECM 5 volt reference LT GRN R pin 50 and engine ground Do you have continuity Replace ECM Go to Step Is the replacement complete 7 5 While monitoring DVOM for continuity Go to Step between ECM 5 volt reference and 6 engine ground disconnect each sensor below one at a time to find the shorted 5 volt reference When continuity to ground is lost the last sensor disconnected is the area of suspicion Inspect 5volt reference supply wire leads for shorts before replacing the sensor IAT ECT CHT TMAP FPP TPS 1 TPS 2 Crankshaft Sensor Camshaft Sensor While disconnecting each sensor one at a time did you loose continuity SM20042002LPGDBW 185 e Replace Sensor Go to step Is the replacement complete 7 Remove all test equipment except the System OK Goto OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 531 check for any stored codes Does the engine operate normally with no stored codes 186 SM20042002LPGDBW SM20042002LPGDBW 187 DTC 532 External 5 V Ref Higher
71. C and ECM connector FPP signal pin 38 Do you have continuity between them Using a DVOM check for continuity between ECM connector FPP signal pin 38 and engine ground Do you have continuity e Replace ECM Go to Step 18 Is the replacement complete System OK Goto OBD System Check Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 612 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 203 613 FPP Higher Than IVS Limit ECM 5 volts FPP Signal Sensor Ground volts IVS Signal Conditions for Setting the DTC Foot Pedal Position Idle Validation Switch Check Condition Engine Cranking or Running MIL On during active fault Fault Condition IVS at idle and FPP voltage greater than 1 12 volts Power Derate 1 50 maximum throttle Low rev Limit 1300 rpm Force Idle 700 rpm Circuit Description The engine load command to the ECM is determined by operator depression of the electronic foot pedal The ECM monitors the foot pedal position and controls the throttle to maintain the commanded power level Because a probl
72. CommPort Plot Log Help Link error attempting reconnect al Toggle Page Gauges Connected at 19200 bps Connected EE Control Ine Toggle Test Cell F10 Ford Power Products ECM interface MIL 23 Coolant Temperature Intake Air Temperature System Vanables EEE 250 250 Engine Speed 105 mm z Min Governor Setpoint 1000 rpm e Max Governor Setpoint 4500 pm E Pulse width 382 ms EGOI 0095 vols Srt EG02 0452 volts 81 degF mI 2 U Minimum Y Value 0 00 Sampling Interval ms 50500 Single Shot Acquisition Foot Pedal Poston Close a c Maximum Y Value 4000 00 Time Inervalls 10 00 100 fect 2 ide 80 60 40 4000 20 05 0x B 07 26 28 30 3 34 36 time s Graphing the values and voltages can be a very useful tool in doing intermittent diagnosis The system diagnostic monitoring software includes graphing and data logging capability These features enhance the ability to diagnose and repair possible problems with the system The graphing feature allows sensor inputs and select control output variables to be plotted in real time while the engine is running To plot a variable you must first TAG the variable you wish to plot To do this use the mouse to highlight the variable and then right click Next press the P key or double click the Plot Log button to invoke the plotting feature You may change t
73. Custom TPS pct Definitions EGO1 vols EMPTY EGO2_vols EMPTY TRIM DC HM hours To select this test mode the engine must be off but the key must be in the ON position The DBW Drive By Wire test mode allows the technician to control the throttle directly with the foot pedal or throttle input and is used during the diagnostic routines specified for FPP and TPS for Spectrum systems that use DBW FPP position displays the current position of the foot pedal as a percentage FPP volts display the voltage which the ECM is reading from the FPP sensor TPS Command displays the commanded throttle position expressed as a percentage which is being sent to the throttle TPS Position is the actual percent of throttle opening being sent to the ECM from the throttle TPS volts display the actual TPS signal voltage the ECM is receiving from the throttle Using a Diagnostic Jumper to Diagnose the ECI System If you do not have access to a laptop computer it is still possible to access the Diagnostic Trouble Codes stored in the memory of the Spectrum system ECM using a diagnostic jumper and the Malfunction Indicator Lamp With the key off connect the diagnostic jumper to the ECI system diagnostic connector located near the ECM Jumper diagnostic pins A and D Turn the ignition on but do not start the vehicle The Malfunction Indicator Lamp MIL will begin to flash The MIL displays three digit codes by flashing the
74. Do have continuity between them Repairs in Engine Electrical Replace ECM Go to Step Is the replacement complete 9 7 e Inspect the throttle wire harness connector Repair the Go to Step terminals for damage corrosion or contamination circuit as 8 Did you find a problem necessary Refer to Wiring Repairs in Engine Electrical Replace the TPS 1 Go to Step Is the replacement complete 9 SM20042002LPGDBW 213 Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 632 check for any stored codes Does the engine operate normally with no stored codes 214 SM20042002LPGDBW SM20042002LPGDBW 215 DTC 633 TPS 2 Signal Voltage High TPS 1 Signal Sensor Ground TPS 2 Signal 5 VOLTS ECM Conditions for Setting the DTC Throttle Position Sensor 2 Check Condition Cranking or Running Fault Condition TPS 2 sensor exceeds 4 8 volts MIL On during active fault Power Derate 1 Low rev limit 1300 rpm Forced idle 700 rpm Circuit Description 216 The Electronic Throttle has two counter acting Throttle position Sensors Two sens
75. EHICLE INTERFACE TT aper pcd tasas CONNECTOR row 018 PED 12A Lock TWR nci ER ERI 1 PURPLE YELLOW 18 c SAC ETE Ca hea Tanne TETE abs 1 trBUEPNK G CURIE 6 sumaonmernme BLUE PINK 18 AUKOUTZ BLUE WHITE 18 CAN Y MTRTWR10 na Taupkeneen s mesi p Soeur b ee A PINK DKGREEN IS JE RELAY FUSED POWER ORANGE OW 18 F CHARGE INDICATION ONTENTS k 12087937 CONNECTOR pen aus LOCK PED 12048074 TERMINAL PED 12020156 TERM 1420 AWG PED 12033997 TERM 12 14 AWG IGNITION COIL MTRTWR8 PED 12162833 CONNECTOR PED 12124075 TERMINAL 2193 CONNECTOR OR EQUIV 4075 TERMINAL OR EQUIV A B MAG PICKUP coos CO11 STARTER RELAY STARTER PINK TAN 18 86 SOLENOID GRAY ORANGE18 85 c009 OR BOSCH THROTTLE SA wires Op t R1 LTBLUE PINK 16 RED TAN 14 RED 14 RED 12 20A RING TERMINAL PED 12033769 HOLDER MIO PED 12033731 COVER 12103505 PED 12052834 LOCK PED 12020156 TERM 14 20 AWG PED 12033997 TERM 12 14 AWG RED TAN 14 WHITE BLUE 18 POWER RELAY x 9 R2 VE 86 85 PED 12033997 TERM C014 BATT 1 BATT 2 RED 12 RED 12 co15 RING TERMINAL Mio 12103505 PED 12033769 HOLDER PED 12033731 COVER PED 12033997 TERM PINK DK GREEN 16 PINK DK GREEN 16 69 4 RING TERMINAL MB
76. ER zz COVER SPLICE WITH TAPE TO INSULATE FROM OTHER WIRES RETWIST AS BEFORE AND TAPE WITH ELECTRICAL TAPE AND HOLD IN PLA FIGURE 1 WIRE HARNESS REPAIR 64 SM20042002LPGDBW Micro Pack Refer to Figure 2 and repair procedure for replacement of a Micro Pack terminal 1 CABLE 3 LOCKING TANG 2 TERMINAL 4 TOOL J33095 BT8234 A FIGURE 2 MICRO PACK CONNECTOR Metri Pack Some connectors use terminals called Metri Pack Series 150 Figure 3 These may be used at the coolant sensor as well as TBI units They are also called Pull To Seat terminals because to install a terminal on a wire the wire is first inserted through the seal 5 and connector 4 The terminal is then crimped on the wire and the terminal pulled back into the connector to seat it in place To remove a terminal 1 Slide the seal back on the wire 2 Insert tool 3 BT 8518 or J 35689 or equivalent as shown in insert A and B to release the terminal locking tab 2 3 Push the wire and terminal out through the connector 1 METRI PACK SERIES 150 FEMALE TERMINAL 2 LOCKING TANG If reusing the terminal reshape the locking tang 2 Weather Pack A Weather Pack connector can be identified by a rubber seal at the rear of the connector This connector which is used in the engine compartment protects against moisture and dirt which could create oxidation and deposits on the terminals Th
77. Flight Data SnapShot SnapShot Closed oop 2 Jn px Base jase Custom Adoptive 2 76 x Oil pressure voltage 50 vols Definitions Definitions Definitions Jom 7 MAP 7 untmsec EMPTY Historic Faults Active Faults JFPPpct EMPTY Double click fault for information Double click fault for information eae EMPTY CL BMi ECT EMPTY 08 MAP voltage low 08 ECT voltage high far BB IAT voltage high EMPTY ECT votage hich Pw_avg CL_BM2 EMPTY Des BMT Jo Rem ma Flight Data FPP Custom TPS_pet Definitions JEGO EGOZ vots EMPTY Fr avo TRIM DC JAM hous The System Fault screen is used to view and clear DTC s which have been set Checking Diagnostic Trouble Codes The System Fault screen contains a listing of all of the Historic and Active DTC s set within the system If a D TC is stored in memory the screen will display that fault in the History column If the fault is active it will also show up in that column Clearing Diagnostic Trouble Codes To clear a DTC from memory use the arrow keys or mouse to move then Press the Enter key to clear the fault from memory NOTE Record faults before erasing them for reference during diagnostics 86 SM20042002LPGDBW DATA STREAM EDIS ECI Serial Communications File Page Flash CommPort Plot Log Help Link error attempting reconnect Gauges EControls
78. IL On during active fault and for 3 seconds after active fault Adaptive Enabled Closed Loop Enabled Engine Shut Down Circuit Description The Oil Pressure Switch is used to communicate a low oil pressure condition to the ECM Engine damage can occur if the engine is operated with low oil pressure The ECM uses an analog voltage input with an internal 5 volt reference If the oil pressure circuit is grounded the input voltage will be near zero If it is open the input will be near 5 volts The switch is normally closed and the fault will set if the circuit becomes open The engine will shut down in the event of this fault to help prevent possible damage 108 SM20042002LPGDBW DTC 115 Oil Pressure Low Step Action 7 Value s Yes No Did you perform the On Board OBD System Goto Step Goto OBD Check 2 System Check Section Verify that the engine has oil pressure 15 psi or Go to Step Repair using a mechanical oil pressure gauge greater 3 faulty Oiling before proceeding with this chart See System Engine Specifications Section 1F Does the engine have oil pressure Key On Engine Running DST connected Greater Go to Step Intermittent in System Data Mode than 600 4 problem Clear DTC 115 rpm Go to Warm the engine by idling until the ECT Intermittent temperature is above 160 degrees F and section has been running for at least one minute Increase engine speed above 600 RPM Does DTC115 reset and cause th
79. OBD DST System Check Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 555 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 193 DTC 556 RTI 3 Loss Microprocessor Conditions for Setting the DTC 194 Engine Control Module Check Condition Key on Fault Condition Internal microprocessor error MIL On until code is cleared by technician Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Power Derate level 2 until fault is cleared manually Circuit Description The ECM runs checks that must be satisfied each time an instruction is executed Several different things can happen within the microprocessor that will cause this fault The ECM will reset itself in the event this fault is set and the MIL will be on until the code is cleared This fault should be erased after diagnosis by removing battery power It will not self erase During this active fault Power Derate level 2 will be enforced When this is enforced maximum throttle position will be 20 This is enforced until the fault is manually cleared SM20042002LPGDBW DTC 556 RTI 3 Loss A
80. OTTLE BODY ASSEMBLY REPLACEMENT Figure 3 Removal Procedure 1 Disconnect the negative battery cable 2 Remove the air intake duct 3 Disconnect the electronic throttle electrical connector Disconnect the FTV supply line Disconnect the PTV vacuum line Disconnect the balance line to the LPR Release mixer fuel inlet hose clamp and remove hose from mixer inlet 8 Remove the two 2 manifold retaining and remove the throttle body assembly 9 Remove gasket and discard 10 Remove the four 4 throttle body to adapt er bolts and retain 11 Remove the throttle body from the FTV SM20042002LPGDBW NO oO R adapter 12 Remove the O ring gasket and discard Installation Procedure Lightly Lubricate the both the o rings of the electronic throttle control device to manifold adapter and FTV adapter Cover Throttle body adapter opening to prevent debris from entering engine until reassembly 13 Install both the o ring and sleeve to the throttle body 14 Insert the throttle body to the FTV adapter 15 Install the adapter O ring seal 16 Install throttle body assembly to the throttle body to manifold adapter and secure with four 4 screws Tighten 9 Nem 80 Ib in 17 Install the manifold gasket 18 Secure the assembly with the two 2 re taining bolts Tighten 12 Nem 106 Ib in 19 Install balance line to the LPR 20 Install the PTV vacuum line 21 Install the fuel supply line to the
81. P pressure of 16 psia or greater Go to OBD System Check Section Intermittent problem Go to Intermittent section 3 Replace TMAP sensor Is the repair complete Remove all test equipment except the System Ok DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 134 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW Go to OBD System Check 133 DTC 135 BP Low Pressure TMAP SENSOR Conditions for Setting the DTC Barometric Pressure Check Condition Key On Fault Condition BP less than 8 3 psia MIL On for active fault and for 2 seconds after active fault Adaptive Disabled for remainder of key on cycle Closed Loop Enabled Circuit Description The BP Barometric Pressure is estimated from the TMAP sensor The barometric pressure value is used for fuel and airflow calculations This fault sets in the event the BP value is out of the normal range 134 SM20042002LPGDBW DTC 135 BP Low Pressure Step Action Value s Yes No Did you perform the On Board OBD System Check KeyOn DST Diagnostic Scan Tool connected in
82. PGDBW DTC 635 TPS 1 Higher Than TPS 2 Value s Yes No Did you 191 the On Board System Go to OBD 2 System Check Section e Key ON Engine OFF Go to Step Intermittent e DST Diagnostic Scan Tool connected in 3 problem System Data Mode Go to Does the DST display more than a 20 Intermittent difference between TPS 1 and TPS 2 section Key OFF Go to Step Go to Step Disconnect wiring harness connector to S 4 throttle Key ON Change DST mode to DBW drive by wire test mode Is the voltage for TPS 1 and TPS 2less than 0 1 volts Key OFF Repair Go to Step Disconnect ECM wiring harness the TPS 1 13 connector or TPS 2 Key ON circuit as necessary Refer to Wiring Repairs in Engine Electrical Jumper TPS 1 and TPS 2 signal to the 5 Go to Step Go to Step volt reference at the throttle connector 6 8 Does DST display TPS 1 and TPS 2 voltage over 4 95 volts e Inspect wire terminals at throttle Repair the Go je os connector for damage corrosion or circuit as contamination necessary Any problems found Refer to Wiring Repairs in Engine Electrical Replace Throttle Go v D Is the replacement complete SM20042002LPGDBW 225 Using a DVOM check for voltage between TPS 1 or TPS 2 the one that is over 0 1 volts and engine ground Do you have voltage Key OFF Disconnect ECM wire harness connector from ECM Using a DVOM check for continuity between throttl
83. PR before installing the coolant line hose fitting 19 Install the outlet water fitting insure orifice is in place and secure with retaining pin 20 Install the inlet water fitting and secure with retaining pin 21 Install vapor outlet fitting and secure with retaining pin 22 Insert the vapor hose to the fuel outlet fit ting and place clamp 23 Install the FTV supply line and secure 24 Secure the LPR to the mounting bracket using the two 2 retaining bolts and tight en to specification SM20042002LPGDBW Tighten 14 Nm 10 ft Ibs 25 Install the water inlet line to the fittings and place clamps 26 Install the water outlet line to the fittings and place clamps 27 Install LPL Refer to Low Pressure Lock off Replacement 28 Install the PTV Refer to Pressure Trim Valve Replacement 29 Tighten fuel line fitting Tighten 27 Nm 20 ft Ibs 30 Replace the drained coolant 31 Start the vehicle and leak check the pro pane fuel system at each serviced fitting 32 Connect the diagnostic service tool and verify the engine is operating in closed loop and no MIL light is present FUEL TRIM VALVE FTV SOLENOID REPLACEMENT Figure 3 Removal Procedure 1 Disconnect the FTV electrical connection 2 Remove the fuel supply hose from the FTV 3 Remove the two 2 retaining bolts and re tain 4 Remove the FTV Installation Procedure Apply a small amount of O ring lubricant to the PTV o
84. Remove the four retaining bolts and lock washer and retain Remove the timing wheel 262 Installation Procedure Remove any debris from the magnetic sensor 10 Rotate crankshaft to position the TDC mark at 12 00 Align the locator mark on the timing wheel with the TDC mark on the crankshaft pul ley Install the four securing bolts and hand tighten Using a marker mark the timing wheel at 12 00 3 00 6 00 and 9 00 positions Place a 035 Brass feeler gauge between the sensor and the timing wheel with the crankshaft at 12 00 and insure feeler gauge moves in and out freely Rotate the crankshaft to each of the marked positions and insure feeler gauge moves in out freely If the gauge does not move freely at each of four marks loosen the four timing wheel retaining bolts and reposition the timing wheel and re secure hand tight and re check air gap Recheck air gap at all mark positions and tighten the four 4 retaining bolts to speci fication Tighten 9 Nem 80 Ib in MAGNETIC PICKUP SENSOR AIR GAP ADJUSTMENT Figure 7 1 Loosen the top and bottom Sensor Bracket bolts slightly and pivot the bracket away from the timing wheel SM20042002LPGDBW Installation Procedure Remove any debris from the magnetic sensor 2 Place a 035 Brass feeler gauge between the Magnetic pickup and the timing wheel and pivot the bracket to the timing wheel 3 Secure the two bracket bolts and tighten to specificati
85. SECTION 0A GENERAL INFORMATION SM20042002LPGDBW Notes Cautions And Warnings Notes Cautions and Warnings are used in this man ual to emphasize important and critical instructions They are used for the following conditions Denotes situations which could influence safety or proper performance of the vehicle or component and to highlight an essential operating procedure or condition A CAUTION Operating procedures or practices that will result in damage to or destruction of the engine if not strictly observed A WARNING Operating procedures or practices that will result in serious injury or loss of life if not correctly followed Fuel Systems Cautions A WARNING Do not smoke carry lighted tobacco or use a lighted flame of any type when working on or near any fuel related component Highly flammable air fuel mix tures may be present and can be ignited causing personal injury A WARNING Do not allow propane to contact the skin Propane is stored in the fuel tank as a liquid When propane contacts the atmosphere it immediately expands into a gas resulting in refrigeration that can cause severe burns A WARNING Do not allow propane to accumulate in areas below ground level such as in a service pit or underground ventilation systems Propane is heavier than air and can displace oxygen creating a dangerous condi tion It is important to note that this manual contains various Warnings Cautions and Note
86. System Data Mode Does DST display BP pressure of 8 3 psia or less Key OFF 3 Disconnect the TMAP sensor from the wiring harness Jumper the 5 volt reference pin C and MAP signal pin D together Key ON Does the DST display BP pressure of 16 00 psia or greater e Inspect TMAP connector and wire harness connector terminals for corrosion contamination or mechanical damage Any problems found Key OFF Disconnect ECM connector Check for continuity between TMAP sensor connector pin D and ECM connector pin 33 Do you have continuity between them SM20042002LPGDBW Go to Step 2 Go to Step 3 Go to Step 4 Repair the Circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step 6 Go to OBD System Check Section Intermittent problem Go to Intermittent section Go to step 8 Go to step 5 Repair the circuit as necessary Refer to Wiring Repairs in Engine Electrical 135 Check for continuity between TMAP sensor connector 5 volt supply pin C and ECM connector pin 50 Do you have continuity between them Go to step Repair the 7 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to step Repair the 17 circuit as necessary Refer to Wiring Repairs in Engine Electrical Remove Jumper that was installed during Go to Step Go to step step 3 9 13 Probe TMAP connector signal circuit D with a test light connected to battery v
87. T Diagnostic Scan Tool connected 3 problem System Data Mode Go to Warm Engine to normal operating Intermittent temperature then run the engine above section 500 rpm for 60 seconds Does DST display ECT temperature of 235 degrees F or greater with the engine running over 500 rpm Verify with a temperature gauge that the Repair Go to step engine coolant is over 235 degrees F Cooling 4 Does the temperature gauge indicate 235 system degrees F or greater Verify ECT circuit function Follow diagnostic test procedure for DTC 122 ECT Low Voltage SM20042002LPGDBW 123 DTC 131 MAP High Pressure TMAP SENSOR Conditions for Setting the DTC Manifold Absolute Pressure Check Condition RPM greater than 800 Throttle Command less than 10 steady MAP and TPS Fault Condition MAP greater than 17 8 psia TPS less than 10 and engine RPM greater than 1800 MIL On Adaptive Disabled for remainder of key on cycle Closed Loop Enabled and allowed to stay at limit Misc Fueling is based on RPM and TPS Limp Home Condition during this fault Circuit Description 124 The TMAP is a combined inlet manifold temperature and pressure sensor connected to the intake manifold It is used to measure the pressure of air in the manifold prior to induction into the engine The pressure reading is used in conjunction with other inputs to determine the airflow rate to the engine which also determines the fuel flow rate This fault will se
88. TC 112 IAT VOLTAGE LOW Value s No Did you TI the On Board OBD System DTE Go to OBD System Check Section Go to step Intermittent 3 problem DST Diagnostic Scan Tool connected in Go to System Data Mode Intermittent section Does DST display IAT voltage of 0 05 or Go to step Go to step Disconnect the TMAP sensor wire 4 5 harness connector Key ON um the Go ie d Disconnect ECM wire harness connector circuit as Check for continuity between TMAP necessary sensor connector ground pin A and TMAP Refer to sensor connector signal pin B Wiring Do you have continuity between them AU in Engine Electrical Check for continuity between TMAP Go to step sensor connector signal circuit pin B and Repair the 7 engine ground circuit as Do you have continuity necessary Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 101 102 Replace ECM Refer to ECM replacement in the Engine Controls Section Is the replacement complete Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 112 check for any stored codes Does the engine operate normally with no stored cod
89. ULATION AS NECESSARY a 4 SPLICE WIRES USING SPLICE CLIPS AND ROSIN CORE SOLDER WRAP EACH SPLICE TO INSULATE 5 WRAP WITH MYLAR AND DRAIN UNINSULATED WIRE 6 OVER WHOLE BUNDLE SECURE AS BEFORE jumper wires between connectors for circuit checking NEVER probe through the Weather Pack seals Use ta chometer adapter J 35812 or equivalent which provides an easy hook up of the tach lead The connector test adapter kit J 35616 or equivalent contains an assortment of flexible connectors used to probe terminals during diagnosis Fuse remover and test tool BT 8616 or equiva lent is used for removing a fuse and to adapt fuse holder with a meter for diagnosis When diagnosing open circuits are often difficult to locate by sight because oxidation or terminal mis alignment are hidden by the connectors Merely wiggling a connector on a sensor or in the wiring harness may correct the open circuit condition This should always be considered when an open circuit or failed sensor is indicated Intermittent problems may also be caused by oxidized or loose connections Before making a connector repair be certain of the type of connector Weather Pack and Meter Pack connectors look similar but are serviced differently TWISTED LEADS RK SCS LOCATE DAMAGED WIRE REMOVE INSULATION AS REQUIRED SPLICE AND SOLDER SPLICE TWO WIRE TOGETHER USING SPLICE CLIPS AND ROSIN CORE SOLD
90. VOM check for continuity Repair the Go to Step between ECM connector pins 11 and 12 shorted 10 to engine ground circuit as Do you have continuity necessary Refer to Wiring Repairs in Engine Electrical Replace CKP sensor Is the replacement complete 10 Replace ECM e 15 the replacement complete Key OFF Inspect the pulse wheel and CKP sensor for mechanical damage corrosion or contamination Did you find a problem Go to Step 16 Go to Step 16 Repair the Go to Step distributor as 12 necessary Refer to Engine Repairs in Engine Section e Check the CKP pulse wheel to sensor 030 to Go to step Go to Step air gap 040 inches 13 14 Is the air gap correct Check CKP for excessive movement Go to Step Go to Step on the bracket Does the CKP show 15 9 excessive movement on the bracket 030 to Go to Step Resetair gap to the correct 040 inches 16 specification Is the gap now set to the correct specification 15 Replace CKP sensor bracket Go to Step Is the replacement complete 16 146 SM20042002LPGDBW Remove all test equipment except the System OK Goto OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the eng
91. W DTC 212 HO2S Open lnactive Step Value s No Did you GD the On Board OBD System Go to Step Go to OBD 2 System Check Section Go to Step Go to Step Key ON Engine Running 5 3 DST Diagnostic Scan Tool connected in System Data Mode Run engine to full operating temperature and then idle for a minimum of 2 minutes Does DST display HO2S voltage fixed between 0 4 and 0 5 volts after 2 minutes of idle run time Back probe HO2S wire harness connector and check for voltage between HO2S connector heater power pin C and engine ground Do you have power Go to step Repair the Back probe HO2S wire harness connector 4 circuit as and necessary check for voltage between HO2S connector Refer to heater ground pin D and battery voltage Wiring positive Repairs Do you have power dpi Go to step Repair the 7 circuit as necessary Check System Power Relay circuit Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 153 Key OFF Disconnect HO2S connector and ECM connector Key ON Check for continuity between HO2S sensor connector ground pin A and ECM 25 sensor ground PIN 49 Do you have continuity between them Check for continuity between HO2S sensor connector signal pin B and ECM connector HO2S signal pin 55 Do you have continuity between them 7 Replace HO2S Sensor Is the replacement complete Inspect ECM connector pins 49 and 55 for damage corrosion or con
92. a mixture of platinum palladium and rhodium The hot gases flow through the catalyst sections where an oxida tion and reduction reactions take place These chemical reactions reduce the amount of CO HC and NOX in the engines exhaust The Exhaust gas then flows through the outlet Figure 9 Three way catalytic converter Engine Control Module To obtain maximum effect from the catalyst and accurate control of the air fuel ratio the emission certified engine is equipped with an onboard computer or Engine control module ECM The ECM is a 32 bit controller which receives in put data from sensors fitted to the engine and fuel system and then out puts various signals to control engine operation One specific function of the controller is to maintain closed loop fuel control Closed loop fuel control is accomplished when the exhaust gas oxygen sensor EGO mounted in the exhaust system sends a voltage signal to the controller The controller then calculates any correction that may need to be made to the air fuel ratio The controller then out puts signals to PTV or the FTV or both mounted in the fuel system to change the amount of fuel being delivered from the regulator or mixer or to the engine 28 The controller also performs diagnostic func tions on the fuel system and notifies the opera tor of malfunctions by turning on a Malfunction Indicator Light MIL mounted in the dash Malfunctions in the system are identified by a D
93. affing or burn through repair if necessary e Check any exhaust pipe extension connector for 16 leaks tighten if necessary e Visually inspect converter to insure muffler is se curely mounted and tail pipe is properly aimed e Check for any leaks at the inlet and outlet of the converter leaks e Check the base of the injector for leaks e Check the injector wire connections to ensure sure they are fully seated and locked e Check the fuel pressure sender electrical con nection to ensure they are fully seated and locked SM20042002LPGDBW CERTIFIED ENGINE MAINTENANCE REQUIREMENTS Install Interval Hours General Maintenance Section TERR a Visual check for leaks LX HE FREE TEE Check engine level LE qx up 34 ge Check coolant level 1x DT Change engine oil and filter Every 200 hours or monthly Check Fuel system for leaks Prior to any service or maintenance activity Inspect Accessory Drive belts si cde p Inspect electrical system i uec rb ER Inspect vacuum lines and fitting T T Inspect all fuel lines and fitting J T T Jj Engine Coolant Section T Jj J 2 Check coolant level 7 X 7 o Every 100 hours or 60 days of operation Change coolant
94. agnostic Scan Tool connected in System Data Mode Does DST display MAP voltage of 0 05 or less with the engine idling e Inspect TMAP connector pins for corrosion contamination or mechanical damage Any problems found Repair the Go to step 5 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step 6 Repair the circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to step 7 Repair the circuit as necessary Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 129 Key OFF Disconnect ECM connector Check for continuity between TMAP sensor connector signal pin D and ECM MAP signal pin 33 Do you have continuity between them e Check for continuity between TMAP sensor connector 5 volt supply signal pin C and ECM 5 volt supply pin 50 Do you have continuity between them 130 e Check for continuity between TMAP sensor connector ground pin A and ECM sensor ground pin 49 Do you have continuity between them Go to step Repair the 17 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to step 13 Go to step Repair the 10 circuit as necessary Refer to Wiring Repairs in Engine Electrical Probe MAP signal circuit with a test light connected to battery voltage Does the DST display MAP voltage of 4 0 or greater Key OFF Disconnect ECM connector Check for continuity between TMAP sensor connector and ECM 5 volt re
95. all sensor readings to be skewed resulting in poor idle quality Engine Mechanical Check the engine for the following Check Broken motor mounts Improper valve timing Low compression Bent pushrods Worn rocker arms Broken or weak valve springs Worn camshaft lobes SM20042002LPGDBW 61 Surges Chuggles DEFINITION The engine has a power variation under a steady throttle or cruise The vehicle feels as if it soeeds up and slows down with no change in the accelerator pedal Preliminary Checks Refer to Important Preliminary Checks Be sure the driver understands the Torque Converter Clutch operation Sensor Checks Check the Heated Exhaust Gas Oxygen Sensor HEGO performance Fuel System Checks Check for Rich or Lean symptom that causes the condition Drive the vehicle at the speed of the complaint Monitoring the oxygen sensors will help identify the problem Check the fuel pressure while the condition exists Refer to LPG Fuel System Diagnosis Verify proper fuel control solenoid operation Verify that the LPG manual shut off valve is fully open Check the in line fuel filter for restrictions Ignition System Checks Check for the proper ignition output voltage using the spark tester J26792 or the equivalent Verify that the spark plugs are correct for use with LPG R46TS Check the spark plugs Remove the plugs and inspect them for the following conditions Wet plugs Cracks Wear Improper gap Burned electrodes
96. als to maintain proper engine equipment function Specific state and federal regulations may require equipment operators to conduct comprehensive engine equipment inspections at more periodic intervals than those specified above This maintenance schedule has no regulatory value and should not be considered representative of any state or federal engine equipment maintenance requirement SM20042002LPGDBW 17 SM20042002LPGDBW SECTION 1A1 LPG FUEL SYSTEM OPERATION SM20042002LPGDBW 21 22 IMPCO SPECTRUM LPG FUEL SYSTEM ERES FRESH AIR LIQUID FUEL HIGH PRESSURE Z Low PRESSURE FUEL 1 5 W C HESS AR FUEL MIXTURE 9 ENGINE COOLANT AR vave vacuum ExHsust cases Air Cleaner SENN Mixer Fuel Filter Electric Lockoff Low Engine Control Pressure Module egulatoi Speed ud C Distributor iming Magnetic Pick up RPM Catalytic Muffler Figure 1 Typical Fuel System Schematic SM20042002LPGDBW Description and Operation of the Fuel Systems Propane Fuel System The primary components of the propane fuel system are the fuel storage tank low pressure regulator LPR fuel mixer module with throttle control device electric fuel lock off solenoid engine control unit ECM fuel trim valve FTV pressure trim valve PTV and three way cata lytic TWC converter The system operates at pressures which range from 355 60 mm 14 0 inches of water column up to
97. an Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Power Derate level 2 until fault is cleared manually Circuit Description 192 The ECM has checks that must be satisfied each time an instruction is executed Several different things can happen within the microprocessor that will cause this fault The ECM will reset itself in the event this fault is set and the MIL will be on until the code is cleared This fault should be erased after diagnosis by removing battery power It will not self erase During this active fault Power Derate level 2 will be enforced When this is enforced maximum throttle position will be 20 This is enforced until the fault is manually cleared SM20042002LPGDBW DTC 555 RTI 2 Loss Values Yes No Did you perform the On Board OBD Go to OBD System Check 2 System Check Section Key On Engine Running Go to Step Intermittent DST Diagnostic Scan Tool connected in 3 problem System Data Mode Go to Clear system fault code Intermittent Does DTC 555 reset with the engine idling eM e Check all ECM power and ground Go to Step Repair the circuits Refer to power and ground 4 circuit as distribution in engine electrical section necessary Are the power and ground circuits Ok Refer to Wiring Repairs in Engine Electrical Replace ECM Go to Step s the replacement complete 5 5 Remove all test equipment except the System OK Go to
98. as commanded This fault will set if the throttle command is 20 less than the actual throttle position During this active fault the MIL light will turn on and the engine will shut down SM20042002LPGDBW DTC 638 Throttle Unable to Close Step Action Value s Yes No 1 Did you perform the On Board OBD System Biol Go to OBD Check 2 System Check Section Key ON Engine OFF Goto Step Intermittent DST Diagnostic Scan Tool connected in 3 problem DBW Drive By Wire test mode Go to Depress Foot Pedal until theThrottle Intermittent Command is between 63 68 section Is the TPS 1 voltage greater than 2 0 volts 3 Key OFF Go to Step Go to Step Disconnect wire harness connector from 6 4 throttle Probe TPS 1 signal circuit with test light connected to battery voltage Key ON Does DST display TPS 1 voltage less than 0 2 volts 4 Key OFF Repair the Go to Step Disconnect ECM wire harness connector circuit as 5 Key ON necessary Refer to Wiring Repairs Using a DVOM check for voltage between throttle connector signal terminal and engine ground Do you have voltage in Engine a A Electrical Replace ECM Go to Step i the replacement complete 13 e Back probe sensor ground circuit at ECM Go 7 ud Go to Step connector with test light connected to 7 battery voltage Does the test light come on e Key OFF Go to Step Repair the e Disconnect ECM wire harness connector 8 circuit as e Using a DVOM c
99. at distress or for possible internal failure Check for possible plugged catalytic converter Refer to Restricted Exhaust System Diagnosis or Exhaust System in the GM MD Service Manual Additional Checks uuu 50 SM20042002LPGDBW Cuts Out Misses DEFINITION A surging or jerking that follows engine speed usually more pronounced as the engine load increases which is not normally felt above 1500 RPM The exhaust has a steady spitting sound at idle low speed or hard acceleration for the fuel starvation that can cause the engine to cut out Preliminary Checks Refer to mportant Preliminary Checks Ignition System Checks Start the engine Wet down the secondary ignition system with water from a spray bottle and look listen for arcing or misfiring as you apply water e Check for proper ignition output voltage with spark tester J 26792 Check for a cylinder misfire Verify that the spark plugs are correct for use with LPG R46TS Remove the spark plugs in these cylinders and check for the following conditions Insulation cracks Wear Improper gap Burned electrodes Heavy deposits Visually Physically inspect the secondary ignition for the following Ignition wires for arcing cross firing and proper routing Ignition coils for cracks or carbon tracking Engine Mechanical Checks Perform a cylinder compression check e Check the engine for the following Improper valve timing Bent pushrods Worn rocke
100. be both MIL and ECM side of terminal F in connector C022 Using a DVOM check for continuity through connector C022 Do you have continuity Inspect the MIL lamp socket connector C022 and ECM terminal 26 for damage corrosion or contamination Did you find a problem Active DTC Diagnostic trouble code is stored in memory Proceed with DTC diagnosis If no active DTC is found in ECM memory return to this page Step 11 Key OFF Disconnect ECM wire harness connector C001 Using a DVOM check for continuity between ECM terminal 26 and battery voltage Do you have continuity Go to Step Repair the damaged socket or terminal as required Refer to Wiring Repairs in Engine Electrical Repair the shorted to ground circuit as necessary Refer to Wiring Repairs in Engine Electrical Repair open circuit in connector C022 Repair the wire harness open circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step 7 SM20042002LPGDBW SM20042002LPGDBW 95 96 DTC 111 IAT High Voltage TMAP SENSOR Conditions for Setting the DTC Intake Air Temperature Check Condition Engine Running Fault Condition IAT Sensor Voltage greater than 4 95 MIL On during active fault and for 2 seconds after active fault Adaptive Disabled during active fault Closed Loop Enabled Circuit Description The TMAP is a combined IAT Intake Air Temperature and MAP Manifold Absolute Pressu
101. connector terminals for corrosion contamination or mechanical damage Any problems found Replace ECM Refer to ECM replacement in the Engine Controls Section Is the replacement complete DSC Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 132 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 131 DTC 134 BP High Pressure TMAP SENSOR Conditions for Setting the DTC Barometric Pressure Check Condition Key On Fault Condition BP greater than 16 psia MIL On for active fault and for 2 seconds after active fault Adaptive Disabled for remainder of key on cycle Closed Loop Enabled Circuit Description The BP Barometric Pressure is estimated from the TMAP sensor The barometric pressure value is used for fuel and airflow calculations This fault sets in the event the BP value is out of the normal range 132 SM20042002LPGDBW DTC 134 BP High Pressure EJ _ Value s Yes No Did you perform the On Board OBD System Go to Step Check 2 Go to step Key On 3 e DST Diagnostic Scan Tool connected in e System Data Mode Does DST display MA
102. continuity between throttle connector TPS 1 signal and ECM connector TPS 1 signal terminal Do you have continuity between them Go to Step Repair the 9 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step Repair the 10 circuit as necessary Refer to Wiring Repairs in Engine Electrical e Using a DVOM check for continuity Repair the Go to Step between throttle connector TPS 1 signal circuit as 11 and engine ground necessary Do you have continuity Refer to Wiring Repairs in Engine Electrical Using DVOM check for continuity between throttle connector TPS 2 signal and ECM connector TPS 2 signal terminal Do you have continuity between them and engine ground between throttle connector TPS 2 signal Do you have continuity Repair the Go to Step e Inspect ECM connector terminals for damage corrosion or contamination Any problems found e Using a DVOM check for continuity Repair the Go to Step circuit as 12 necessary Refer to Wiring Repairs in Engine Electrical 13 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step 14 e Replace ECM Is the replacement complete 230 SM20042002LPGDBW Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and
103. d and retained to the engine or chassis e Check to insure any additional electrical devices installed by the owner are prop erly installed in the system e Check the MIL charging and oil pressure lights for operation by starting the engine and checking that the light illuminates for the prescribe period of time before turning out Engine Crankcase Oil Oil Recommendation Prior to changing the oil select oil based on the pre vailing daytime temperature in the area in which the equipment will be operated The chart in figure 1 is a guide to selecting the proper crankcase oil 11 IMPORTANT Oils containing solid additives non Checking filling Engine Oil Level detergent oils or low quality oils are not recom mended by the engine manufacturer Care must be taken when checking engine oil level FOR THE BEST FUEL ECONOMY AND COLD STARTING SELECT THE LOWEST SAE VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE Oil level must be maintained between the ADD IF NEITHER SAE 10W 30 HOT WEATHER mark and the FULL mark on the dipstick To ensure NOR SAE 15W 40 GRADE that you are not getting a false reading make sure OILS ARE AVAILABLE SAE 30 GRADE MAY DE USED AT the following steps are taken before checking the oil DEGREES 40 F SAE 40 TEMPERATURES ABOVE 27 DEGREES C 00 F DO NOT USE SAE 10W 40 1 GRADE NOT RECOMMENDED 2 COLD WEATHER 3 Figure 1 Engine Oil Viscosi
104. dividual cylinders If the Spark Kill diagnostic mode is selected with the engine running below 1000 RPM the minimum throttle command will lock into the position it was in when the test mode was entered If the Spark System Test mode is selected with the engine running above 1000 RPM the throttle will continue to operate normally Disabling Ignition Outputs To disable the ignition system for an individual cylinder use the mouse to highlight the Spark Kill button and select the desired coil The spark output can be re enabled by using the mouse to highlight the Spark Kill button and selecting Normal If the engine is running below 1000 RPM the spark output will stay disabled for 15 seconds and then re set If the engine is running above 1000 RPM the spark output will stay disabled for 5 seconds and then re set This test mode has a timeout of 10 minutes Record the rpm drop related to each spark output disabled The Spark outputs are arranged in the order which the engine fires not by cylinder number SM20042002LPGDBW 89 THROTTLE TEST EDIS ECI Serial Communications xj File Page Flash CommPort Plot Log Help Fauks Controls hc ra em Connected Control and instrumentation Specialists _Toggk Test Cell F10 feutAccess ML Sysem Saws Duce S E RET Engine Speed 8 m Rudhode Stopped TPS command 00 x
105. dle Intermittent section Remove all test equipment except the DST System OK Connect any disconnected components System Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 613 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 205 DTC 614 FPP Lower Than IVS Limit ECM LT GRN RED 5 volts FPP Signal 797971 BLK LT GRN Sensor Ground volts PPL YEL 39 IVS Signal Conditions for Setting the DTC Foot Pedal Position Idle Validation Switch Check Condition Engine Cranking or Running MIL On during active fault Fault Condition IVS off idle and FPP voltage less than 880 volts Power Derate 1 50 maximum throttle Low rev Limit 1300 rpm Force Idle 700 rpm Circuit Description The engine load command to the ECM is determined by operator depression of the electronic foot pedal The ECM monitors the foot pedal position and controls the throttle to maintain the commanded power level Because a problem with the foot pedal signal can result in a higher or lower power than intended by the operator the pedal used with this control system incorporates
106. e CL Active FPP command 00 X 2 4 zaj 01 142 CylinderHeadTemp 3976 degF Govemor switch state Gov3 FPP postion 00 X 00 o 14 1 Manifold Temperature 789 degF Active governor type Min TPS1 voltage 0 696 volts 4 o nu Intake Air Temperature 787 degF Active governor made Droop TPS2 voltage 4267 vols 5 m 00 Vbat 138 vols Broke pot evel pen FPP1 voltage 0434 vols 6 00 00 Vsw 137 volts Oi pressure state OK FPP2 voltage 0100 volts Hour meter 12628 hours IVS voltage 5000 volts Cumulative starts 38 starts Closed Loop Digital input Voltages Diagnostic Modes EGO1 0882 vots Fuelselect votage 104 volts Spark kil Normal Closed loop 1 00 Fuel pump voltage 136 volts Injector kill w Normal Adaptive 1 20 Govl voltage 206 vols DBW test mode 1 FO Gov2 voltage 238 vots zal EGO2 0 452 vols Coil 3 FO ee 07 Overspeed voltage 50 volts Coil 4 FO ata ye SERE ustom EE 7 Dil pressure voltage 50 vols Coil 5 FO ions Definitions Definitions fuel state EMPTY Juntm_sec Historic Faults Active Faults pm EMPTY TPS pct Mar EMPTY CL BMi ECT EMPTY EL_BM2 EMPTY Vox CL EMPTY Fw_avg CL BM2 EMPTY A A BMT Flight Data FPP pet Custom TPS pct Definitions vols EMPTY JEGO vots EMPTY Pweg TRIM DC HM hours The Spark Kill diagnostic mode allows the technician to disable the ignition on in
107. e and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 516 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 183 DTC 531 External 5V Ref Lower Than Expected LT GRN R Conditions for Setting the DTC External 5V reference Check Condition Cranking with battery voltage greater than 8 volts and engine running Fault Condition 5V reference voltage lower than 4 6 volts MIL On during active fault and for 2 seconds after active fault Adaptive Disabled during active fault Closed Loop Enabled Circuit Description The External 5 Volt supply powers some of the sensors and other components in the system The accuracy of the 5 Volt supply is very important to the accuracy of the sensors and therefore controlled by the ECM The ECM monitors the 5 volt supply to determine if it is overloaded shorted or otherwise out of specification This fault will set if the 5 Volt reference is below 4 6 volts 184 SM20042002LPGDBW DTC 21 External 5V Reference Lower Than Expected a NNNM Values Yes No Did you PG the On Board OBD System Go to OBD 2 System Check Section Key ON Engine Running Go to Step Intermittent DST Diagnostic Scan Tool connected 3 problem System Fault Mode Go to Does DST display DTC 5
108. e connector TPS 1 signal and ECM connector TPS 1 signal terminal Do you have continuity between them Go to Step Repair the 9 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step Repair the 10 circuit as necessary Refer to Wiring Repairs in Engine Electrical e Using a DVOM check for continuity Repair the Go to Step between throttle connector TPS 1 signal circuit as 11 and engine ground necessary Do you have continuity Refer to Wiring Repairs in Engine Electrical Using DVOM check for continuity between throttle connector TPS 2 signal and ECM connector TPS 2 signal terminal Do you have continuity between them and engine ground between throttle connector TPS 2 signal Do you have continuity Repair the Go to Step e Inspect ECM connector terminals for damage corrosion or contamination Any problems found e Using a DVOM check for continuity Repair the Go to Step circuit as 12 necessary Refer to Wiring Repairs in Engine Electrical 13 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step 14 e Replace ECM Is the replacement complete 226 SM20042002LPGDBW Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full
109. e engine is correct by measuring the oxygen content in the exhaust gas The ECM uses this information to correct the fuel flow with the Closed Loop multiplier and Adaptive multiplier This fault will set if the adaptive multiplier exceeds the limits of normal operation Diagnostic Aids Always diagnose any other ECM codes that are present before beginning this diagnostic procedure Fuel System High secondary fuel pressure will cause the system to run rich A worn fuel mixer faulty PTV pressure trim valve or FTV fuel trim valve can also cause the system to run rich Fuel Quality A drastic variation in fuel quality very high butane content may cause the system to run rich Be sure that the specified HD 5 or HD 10 motor fuel grade propane is used 162 SM20042002LPGDBW DTC 244 Adaptive Learn Low LPG Value s Yes No Perform the On Board OBD System Check Are any other DTCs present Visually and physically check the following Go A d to Step items The air intake duct for being collapsed or restricted The air filter for being plugged ECM grounds for being clean and tight Refer to Section 1C Engine Electrical Power and Ground Distribution Fuel System Diagnostics Refer to Section 1B Fuel System Diagnostics Was a repair made Got o Se Go to Step 2 Diagnose any other DTC codes before proceeding with this chart Have any other DTC codes been detected diagnosed and repaired Key OFF Disconnect HO
110. e engine to shut down Replace oil pressure switch Go to Step Is the replacement complete 9 Key OFF Go to Step Repair the Disconnect ECM harness connector C001 7 circuit as Using a DVOM check for continuity necessary between oil pressure switch connector LG Refer to BK wire and ECM connector pin 37 Wiring Do you have continuity between them DARA in Engine Electrical SM20042002LPGDBW 109 Key OFF Goto Step Goto Step Disconnect oil pressure switch harness 6 5 4 connector C005 Jumper the pressure switch LG BK wire to engine ground Clear DTC 115 Start engine let idle for at least one minute with ECT over 160 degrees F Increase engine speed above 1300 RPM Does DTC 115 reset Repair the Go to Step circuit as 8 necessary Refer to Wiring Repairs in Engine Electrical Go to Step 9 System OK Go to OBD System Check 110 SM20042002LPGDBW Inspect ECM connector pin 37 for damage corrosion or contamination Did you find a problem Replace ECM Is the replacement complete driveability After operating the engine within the test parameters of DTC 115 check for any stored codes Does the engine operate normally with no stored codes Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating tempe
111. e manifold in response to elec trical from the control module Fuel Lock A solenoid controlled valve located in the fuel line to stop the flow when the engine stops or the ignition switch is off Gasohol 10 percent ethanol 90 percent gasoline Often referred to as E 10 Gasoline A motor vehicle fuel that is a complex blend of hydrocarbons and additives Typical octane level is 89 Greenhouse Effect A scientific theory that suggests that excessive levels of carbon dioxide from the burning of fossil fuels is causing the atmosphere to trap heat and cause global warming HD 10 A fuel of not less than 80 liquid volume propane and not more than 10 liquid volume propylene HD 5 A fuel of not less than 90 liquid volume propane and not more than 5 liquid volume propylene HDV Heavy Duty Vehicle Hg Chemical symbol for mercury Used in reference to vacuum in of Hg Hydrocarbon A chemical compound made up of hydrogen and carbon HC A major pollution emission of the internal combustion engine Gasoline and almost all other fuels are hydrocarbons Hydrostatic Relief Valve A pressure relief device installed in the liquid propane hose on a propane fuel system IAT Intake Air Temperature Ideal Mixture The air fuel ratio at which the best compromise of engine performance to exhaust emissions is obtained Typically 14 7 1 Ignition Reserve The difference between available voltage and the required voltage ILEV Inherently Low Emissio
112. e manual shut off valve on the LPG tank CAUTION When disconnecting LPG fuel lines liquid LPG may be present Perform this step in a well ventilated area 3 Loosen the fuel inlet hose fitting at the inlet of the LPL Was fuel present when the fitting was loosened 1 Turn OFF the ignition 2 Connect the test light to chassis ground and probe pin A of the LPL connector 3 Crank the engine The test light should illuminate Go to Step Go to Step 23 17 Go to Step Go to Step 20 21 Go to Step Go to Step 23 19 Go to Step 26 Go to Step 26 SM20042002LPGDBW Does the test light illuminate ge Remove the LPG fuel filter LPL Remove the filter from the LPL Empty the contents of the inlet side of the LPG fuel filter onto a clean surface Inspect the contents of the LPG fuel filter for an excessive amount of foreign material or water If necessary locate and repair the source of contamination Verify the LPG fuel filter is not restricted or plugged Was a problem found The fuel supply system or hoses are plugged or restricted locate and repair the problem Is the action complete Replace the fuel filter Refer to Fuel Filter Replacement Is the action complete Repair the open in the lock off ground cir cuit Go to Step 26 Go to Step 26 Go to Step 26 Is the action complete Repair the open in the lock off power OEM fuel pump circuit Is the action complete
113. e operating on LPG to a vehicle operating on gasoline as the fuels do have different drive feel characteristics Remove the air filter and check for dirt or restriction Check the vehicle transmission Refer to the OEM transmission diagnostics Check for a restricted fuel filter contaminated fuel or improper fuel pressure Refer to LPG Fuel System Diagnosis Check for the proper ignition output voltage with the spark tester J 26792 or the equivalent Check for proper installation of the mixer module assembly Check all air inlet ducts for condition and proper installation Check for fuel leaks between the LPR and the mixer Verify that the LPG tank manual shut off valve is fully open Verify that liquid fuel not vapor is being delivered to the LPR Check the Heated Exhaust Gas Oxygen Sensor HEGO for contamination and performance Check for proper operation of the MAP sensor Check for proper operation of the TPS sensor Check the exhaust system for a possible restriction Inspect the exhaust system for damaged or collapsed pipes Inspect the muffler for signs of heat distress or for possible internal failure Check for possible plugged catalytic converter SM20042002LPGDBW Engine Mechanical Check Additional Check SM20042002LPGDBW Check the engine for the following Engine compression Valve timing Improper or worn camshaft Refer to Engine Mechanical in the Service Manual Check the ECM grounds for bei
114. eck engine for large manifold vacuum leaks Refer to Fuel Systems Section 1B Symptom Diagnostics Did you find and correct the vacuum leak Go to Step Go to Step 8 7 Go to step 9 Go to Step Go to OBD 9 System Check Section SM20042002LPGDBW 241 Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 651 check for any stored codes Does the engine operate normally with no stored codes 242 SM20042002LPGDBW SM20042002LPGDBW 243 DTC 652 Fuel Rev Limit TPS 1 Signal Sensor Ground TPS 2 Signal 5 VOLTS Conditions for Setting the DTC Fuel Rev Limit Check Condition Engine Running Fault Condition Engine RPM greater than 4000 for 2 seconds continuously MIL On during active fault Adaptive Enabled Closed Loop Enabled Circuit Description This fault will set anytime engine RPM exceeds 4000 for 2 seconds or more continuously When these conditions are met the ECM shuts off the fuel injectors This is to help prevent engine or equipment damage The MIL will be on during this active fault 244 SM20042002LPGDBW DTC 652 Fuel Rev Limit Step Action
115. ed to determine if the fuel flow to the engine is correct by measuring the oxygen content in the exhaust gas The ECM uses this information to correct the fuel flow with the Closed Loop multiplier and the adaptive multiplier This fault sets if the Closed Loop multiplier exceeds the limits of normal operation When the multiplier cannot correctly modify the fuel flow within its limits it is limited at 35 Diagnostic Aids Always diagnose any other ECM codes that are present before beginning this diagnostic procedure Fuel System High secondary fuel pressure can cause the system to run rich A worn fuel mixer faulty PTV pressure trim valve or FTV fuel trim valve can also cause the system to run rich Fuel Quality A drastic variation in fuel quality very high butane content may cause the system to run rich Be sure that the specified HD 5 or HD 10 motor fuel grade propane is used 156 SM20042002LPGDBW DTC 224 Closed en NN Multiplier Low LPG Action Value s Yes No Go to Step 2 Go p Key On Engine Running DST Diagnostic Scan Tool connected in System Data Mode Run engine to full operating temperature and then idle for a minimum of 2 minutes Does DST display HO2S voltage fixed above 0 7 volts after 2 minutes of idle run time Did you AU the On Board OBD System Repair wire harness shorted signal to voltage Refer to Wiring Repairs in Engine Electrical Key OFF Disconnect HO2S wire
116. ed while the engine is off Throttle Position Sensor The throttle position sensor measures the opening of the throttle SM20042002LPGDBW Spectrum Diagnostic Section DIAGNOSTICS OVERVIEW OF THE SPECTRUM FUEL SYSTEM The Spectrum Fuel system has built in diagnostics for trouble shooting The system has a dash mounted Malfunction Indicator Lamp MIL for indication of system problems MALFUNCTION INDICATOR LAMP MIL Most engine control system related problems that affect emissions or driveability of the vehicle will set a DTC Diagnostic Trouble Code and illuminate the Malfunction Indicator Lamp The MIL has the following functions 1 It notifies the driver of a problem with the fuel system ignition system or emission control system so the driver can arrange for service as soon as possible 2 It will display DTC s that have been stored due to a system malfunction The lamp should come on when the key is in the ON position and the engine is not running This feature verifies that the lamp is in proper working order If the lamp does not come on with the vehicle key on engine off repair it as soon as possible Once the engine is in start or run mode the lamp should go off If the lamp illuminates while the engine is in the start or run mode there is a current Diagnostic Trouble Code SPECTRUM DIAGNOSTIC TROUBLE CODES DTC Diagnostic Trouble Codes are set when the Spectrum ECM Electronic Control Module runs a diagnostic se
117. em with the foot pedal signal can result in a higher or lower power than intended by the operator the pedal used with this control system incorporates a sensor with an idle validation switch Checks and cross checks are constantly conducted by the ECM to determine the validity of the signals The Idle Validation Switch IVS is a normally closed contact idle that opens the IVS circuit to the ECM when the pedal is depressed more than the idle position 204 SM20042002LPGDBW DTC 613 FPP Higher Than IVS Limit Step No 1 Did you perform the On Board OBD System Go to Step m Go to OBD Check uU Check Section M 2 Key ON Engine OFF Go to Step 3 Go to Step 7 e DST Diagnostic Scan Tool connected in System Data Mode Does the DST display IVS idle with the foot pedal fully depressed 3 e Key OFF Go to Step 4 Go to Step 5 e Disconnect foot pedal from harness e Key ON Does DST display IVS idle 7 Replace foot pedal Go to Step 8 Is the replacement complete Key OFF Repair the Go to Step 6 Disconnect ECM wire harness connector circuit as Using a DVOM check for continuity necessary between IVS signal and engine ground Refer to Do you have continuity between them Wiring Repairs in Engine Electrical Replace ECM Go to Step 8 Is the replacement complete Depress foot pedal until DST reads FPP 1 1 to 1 3 Go to Step 4 Intermittent voltage between 1 1 and 1 3 volts volts Does DST display IVS i
118. er column gauge or a manometer to the secondary test port of the low pressure regulator LPR Crank the engine and observe the pressure reading for the LPR secondary pressure Does the fuel pressure indicate a vacuum Go to Step Go to Step 9 is present Go to Step Go to Step 11 10 36 SM20042002LPGDBW the LPR and the mixer assembly for damage or leakage 1 Inspect the air intake stream to the mixer assembly and the throttle body for vacuum leaks Inspect the vacuum hoses from the mixer to the PTV solenoids for proper connection and condition Go to Step Go to Step Was a problem found and repaired 6 24 2 Inspect the fuel hose connection between Go to Step Go to Step 26 12 Was a problem found and repaired Connect a 0 10 psi gauge to the primary test port of the low pressure regulator LPR Crank the engine and observe the pressure reading for the LPR primary Go to Step Goto Step 22 13 Is the fuel pressure ABOVE the specified value 1 Turn OFF the ignition 2 Disconnect the LPL connector 3 Install a test light between the pins of the LPL connector 4 Crank the engine The test light should illuminate Go to Step Go to Step Does the test light illuminate 14 16 Using a DVOM check the resistance of the low pressure lock off LPL 19 3240 Is the resistance within the specified Go to Step Go to Step range 15 23 SM20042002LPGDBW 37 1 Turn the ignition OFF 2 Close th
119. erating condition the ECM provides a electrical pulse to both the FTV and the PTV which controls the amount of fuel being introduced into the air stream The PTV is connected to the Air Valve Vacuum AVV which reduces the amount of fuel flow to the regulator the FTV introduces additional fuel into the air stream By cycling the PTV more frequently and the FTV less frequently the air fuel ratio can be leaned by decreasing the PTV duty cycles and increasing the FTV duty cycles the air fuel ratio can be increased Figure 7 Pressure Trim Valve and Fuel Trim Valve Throttle Control Device Drive By Wire Engine speed control is maintained by the amount of pressure applied to the foot pedal located in the engine compartment In a Drive By Wire DBW application there is no direct connection between the operator pedal and the throttle shaft Speed and load control are deter mined by the ECM Defaults programmed into the ECM software and throttle position sensors allow the ECM to maintain safe operating con SM20042002LPGDBW trol over the engine In a drive by wire application the Electronic Throttle Control device or throttle body as sembly is connected to the intake manifold of the engine The electronic throttle control de vice utilizes an electric motor connected to the throttle shaft In addition a Foot Pedal Position sensor FPP is located in the operator s com partment When the engine is running electrical si
120. es Go to step 8 System OK Go to OBD System Check SM20042002LPGDBW SM20042002LPGDBW 103 DTC 113 IAT Higher Than Expected 1 TMAP SENSOR Conditions for Setting the DTC Intake Air Temperature Check Condition Engine Running Fault Condition Intake Air Temperature greater than 200 degrees F and engine RPM greater than 1000 e MIL On for active fault and for 15 seconds after active fault Adaptive Disabled during active fault Closed Loop Enabled Power Derate 1 Circuit Description The TMAP is a combined IAT Intake Air Temperature and MAP Manifold Absolute Pressure sensor A temperature sensitive resistor is used in the TMAP located in the intake manifold of the engine It is used to monitor incoming air temperature and the output in conjunction with other sensors is used to determine the airflow to the engine The ECM provides a voltage divider circuit so that when the air is cool the signal reads higher voltage and lower when warm The IAT is a calculated value based mainly on the IAT sensor at high airflow and influenced more by the ECT Engine Coolant Temperature at low airflow This fault will set if the Intake Air Temperature is greater than 200 degrees F for 60 seconds or more and engine RPM is greater than 1000 Power Derate 1 will then be enforced During this fault maximum throttle position is 50 and the MIL will be on Diagnostic Aids 104 This fault will set when inlet
121. est mode Does the DST display TPS 2 voltage of 0 2 volts or less with the throttle closed e Slowly depress Foot Pedal while Go to Step Intermittent observing TPS 2 voltage 4 problem Does TPS 2 voltage ever fall below 0 2 volts Go to Intermittent section Key OFF Go to Step Go to Step Disconnect electronic throttle connector 7 S Jumper the 5 volt reference circuit and TPS 2 signal circuit together at the throttle connector Key ON Does DST display TPS 2 voltage of 4 0 volts or greater e Key OFF Goto Step Repairthe e Disconnect ECM wire harness connector 6 circuit as Using a DVOM check continuity between necessary TPS 2 connector signal and ECM connector Refer to TPS 2 signal terminals Wiring Do have continuity between them Repairs in Engine Electrical Replace ECM Go 2 Is the replacement complete 7 Inspect the throttle wire harness ee the 2 to Step connector terminals for damage circuit as corrosion or contamination necessary Did you find a problem Refer to Wiring Repairs in Engine Electrical Replace throttle Go to Step i the replacement complete 9 SM20042002LPGDBW 221 Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine per
122. ference signal Do you have continuity between them 11 Repair the Go to Step 16 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to step 17 Go to Step Repair the 14 circuit as necessary Refer to Wiring Repairs in Engine Electrical Inspect ECM connector and wire harness connector terminals for corrosion contamination or mechanical damage Any problems found Replace ECM Refer to ECM replacement in the Engine Controls Section Is the replacement complete e Disconnect ECM connector e Check for continuity between TMAP sensor connector signal circuit pin D and ECM signal PIN 33 Do you have continuity between them e Check for continuity between TMAP Repair the Go to Step sensor connector 5 volt reference pin C circuit as signal and engine ground necessary Do you have continuity Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW e Check for continuity between TMAP sensor connector signal pin D and engine ground Do you have continuity Repair the Go to step 15 Circuit as necessary Refer to Wiring Repairs in Engine Electrical Repair the Go to Step 16 Circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step 18 Replace TMAP sensor m Go to step 17 ls the replacement complete 18 Remove all test equipment except the System OK Go to OBD System Check Inspect ECM connector and wire harness
123. form the equipment 0 Check for contamination 9 Tap the opening of the filter on a clean cloth 10 Check for debris 11 Check canister for proper mounting direction 12 Reinstall the filter housing to the equipment 13 Tighten the inlet and outlet fittings to specifica tion 14 Open the manual valve The fuel cylinder manual valve contains an Excess Flow Check Valve open the manual valve slowly to prevent activating the Excess Flow Check Valve 15 Check for leaks at the inlet and outlet fittings and the filter housing end connection using a 14 soapy solution or an electronic leak detector if leaks are detected make repairs Low Pressure Regulator Maintenance And Inspection The Low Pressure Regulator LPR components have been specifically designed and calibrated to meet the fuel system requirements of the emission certified engine The regulator should not be disas sembled or rebuilt If the LPR fails to operate or develops a leak the LPR should be replaced with the OEM recommended replacement parts When inspecting the regulator check for the following items e Check for any fuel leaks at the inlet and outlet fittings e Check for any fuel leaks in the regulator body e Check the inlet and outlet fittings of the coolant supply lines for water leaks e Check the coolant supply lines for hardening cracking chaffing or splits If any of these condi tions exist replace coolan
124. formance and driveability After operating the engine within the test parameters of DTC 634 check for any stored codes Does the engine operate normally with no stored codes 222 SM20042002LPGDBW SM20042002LPGDBW 223 DTC 635 TPS1 Higher Than TPS 2 TPS 1 Signal Sensor Ground TPS 2 Signal 5 VOLTS Conditions for Setting the DTC Throttle Position Sensor 1 amp 2 Check Condition Key On Fault Condition TPS1 higher than TPS2 MIL On for remainder of key on cycle Power Derate 1 Low rev limit 1300 rpm Forced idle 700 rpm Circuit Description 224 There are 2 Throttle Position Sensors located within the throttle which use variable resistors to determine signal voltage based on throttle plate position TPS1 will read low voltage when closed and TPS2 will read high voltage when closed The TPS1 and TPS2 percentages are calculated from these voltages Although the voltages are different the calculated values for the throttle position percentages should be very close to the same The TPS values are used by the ECM to determine if the throttle is opening as commanded This fault will set if TPS1 is 20 or more higher than TPS2 At this point the throttle is considered to be out of specification or there is a problem with the TPS signal circuit Power derate 1 will be enforced limiting the throttle to 50 maximum Low rev limit and forced idle will also be enforced during this fault SM20042002L
125. gnals are sent from the foot pedal position sensor to the engine ECM when the operator depresses or release the foot pedal The ECM then sends an electrical signal to the motor on the electronic throttle control to increase or decrease the angle of the throttle blade thus increasing or decreasing the air fuel charge to the engine The electronic throttle control device incorpo rates two internal Throttle Position Sensors TPS which provide output signals to the ECM as to the location of the throttle shaft and blade The TPS information is used by the ECM to cor rect for speed and load control as well as emis sion control a Throttlebody sealing Rings Bosch Electronic Throttlebody lt lt p Figure 8 Electronic Throttle control device Drive by Wire throttle body assembly Three Way Catalytic Muffler The emission certified engine has been de signed and calibrated to meet the emission standards in effect for 2004 To help meet the emission requirements the vehicle has been equipped with a Three Way Catalytic TWC muffler The catalyst muffler is a three way 27 catalyst sound damping and spark arresting unit Besides controlling the noise created from the combustion process and preventing sparks from escaping from the exhaust system the most important function is treating the exhaust gases which are created from the combustion process The three way catalyst consists of a honeycomb coated with
126. h no stored codes 218 SM20042002LPGDBW SM20042002LPGDBW 219 DTC 634 TPS 2 Signal Voltage Low TPS 1 Signal Sensor Ground TPS 2 Signal 5 VOLTS Conditions for Setting the DTC Throttle Position Sensor 2 Check Condition Cranking or Running Fault Condition TPS 2 sensor voltage less than 0 2 MIL On during active fault Power Derate 1 Low rev limit 1300 rpm Forced idle 700 rpm Circuit Description 220 The Electronic Throttle has two counter acting Throttle Position sensors Two sensors are used for improved safety and redundancy The Throttle Position Sensor TPS2 uses a variable resistor to determine signal voltage based on throttle plate position and is located within the throttle Less opening results in higher voltage and greater opening in lower voltage The TPS value is used by the ECM to determine if the throttle is opening as commanded This fault will set if voltage is below 0 2 volts at any operating condition while the engine is cranking or running Power derate 1 will be enforced limiting the throttle to 50 maximum Low rev limit and forced idle will also be enforced during this fault SM20042002LPGDBW DTC 634 TPS 2 Signal Voltage Low Value s Yes No Did you an the On Board OBD System Go to Step Go to OBD 2 System Check e Key ON Engine OFF Go to Step Go to Step e DST Diagnostic Scan Tool connected in 4 3 DBW Drive by Wire throttle t
127. harness connector Disconnect ECM wiring harness connector Key ON Using a high impedance DVOM check for voltage between HO2S connector signal pin B and engine ground Do you have voltage SM20042002LPGDBW Go to OBD System Check Section Intermittent problem Go to Intermittent section Refer to Diagnostic Aids for DTC 224 157 DTC 243 Adaptive Learn High LPG DK GRN ORN BLK LT GRN Sensor Ground Heater PNK DK GRN To Engine Ground To System Power Relay n1 O I Conditions for Setting the DTC Heated Oxygen Sensor Check Condition Engine Running Fault Condition Adaptive multiplier out of range greater than 30 MIL Disabled Adaptive Enabled Closed Loop Enabled Circuit Description The HO2S sensor is used to determine if the fuel flow to the engine is correct by measuring the oxygen content in the exhaust gas The ECM uses this information to correct the fuel flow with the Closed Loop multiplier and Adaptive multiplier This fault will set 1f the adaptive multiplier exceeds the limits of normal operation Diagnostic Aids If any other DTCs are present diagnose those first Oxygen Sensor Wire Heated Oxygen sensor wires may be mis routed and contacting the exhaust manifold Vacuum Leaks Large vacuum leaks and crankcase leaks can cause a lean exhaust condition at especially at light load Injectors System will be lean if an injector driver or
128. he desired time interval for each display screen The default is 10 seconds This can be increased or decreased as necessary to display the desired results You can also change the sample rate You are now ready to plot Simply click the START button to observe the plotted variables The plot sweeps across the screen from left to right To pause the display screen press the SPACE BAR at any time during plotting To continue plotting simply press the SPACE again To stop the plotting feature simply click the STOP button To exit the plotting screen click the CLOSE button The range of each variable is listed along the left side of the display and the time is listed along the bottom of the screen 88 SM20042002LPGDBW Ignition System Test EDIS ECI Serial Communications n laj x File Page Flash CommPort Plot Log Help i 5 4 Link error attempting reconnect al Toggle Page e Faults EControls Inc Connected at 19200 bps T Connected Control and hsinsmeaifon Specie mj ToodeTestCel Fio MIL I ELIE ES DEW Variablen Abe Teste Engine Speed 1027 mm Run Mode Running TPS command 38 firing order dwellms firing order voltage voltage Manifold Pressure 425 psia Fani Tope Ge TPS position 37 X i ugs 1 o 144 Coolant Temperature 97 6 degF Fuel Control Mod
129. heck for continuity necessary between throttle connector signal ground Refer to and ECM signal ground circuit terminals Wiring Do you have continuity between them Engine Electrical De empemeremme a 5 the replacement complete 13 SM20042002LPGDBW 237 Go to Step Go to Step 10 11 Go to Step 13 Repair the Go to Step circuit as 12 necessary Refer to Wiring Repairs in Engine Electrical Go to Step 13 e Check throttle for foreign object in bore Is the removal complete Inspect the throttle wire harness connector terminals for damage corrosion or contamination Did you find the problem e Replace throttle Is the replacement complete Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 638 check for any stored codes Does the engine operate normally with no stored codes 238 SM20042002LPGDBW SM20042002LPGDBW 239 DTC 651 Max Govern Speed Override PNK WHT TAN ORN PPL LT BLU TPS 1 Signal BLK LT GRN Sensor Ground LT BLU DK BLU TPS 2 Signal LT GRN RED 5 VOLTS Conditions for Setting the DTC
130. iagnostic Code number In addition to notify ing the operator of the malfunction in the sys tem the controller also stores the information about the malfunction in its memory A techni cian can than utilize a computerized diagnostic tool to retrieve the stored diagnostic code and by using the diagnostic charts in this manual determine the cause of the malfunction In the event a technician does not have the computer ized diagnostic tool the MIL light can be used to identify the diagnostic code By following specific steps the technician can activate the blink feature and count the number of blinks to determine the diagnostic code number to locate the fault in the system Heated Exhaust Gas Oxygen Sensor The Heated Exhaust Gas Oxygen Sensor HEGO is mounted in the exhaust system downstream of the engine The HEGO is used to measure the amount of oxygen present in the exhaust stream and communicate that to the ECM via an electrical signal The amount of oxygen present in the exhaust stream indicates whether the fuel air ratio is to rich or to lean If the HEGO sensor signal indicates that the exhaust stream is to rich the ECM will decrease or lean the fuel mixture during engine operation if the mixture is to lean the ECM will richen the mixture The ECM continuously monitors the HEGO sensor output if a rich or lean condition is present for an extended period of time and the ECM cannot correct the condition the ECM will set a diagn
131. in closed loop and no MIL lights are present THREE WAY CATALYTIC CONVERTER MUFFLER REPLACEMENT 1 Remove the TWC muffler using the OEM end product processes Installation Procedure The Three Way Catalytic converter is specifi cally designed to meet the emission control of the certified engine Use only the OEM speci fied parts 2 Install the TWC muffler using the OEM end product processes 3 Start engine Check for any DTC codes and clear 5 Verify engine is in closed loop and no MIL lights are present SM20042002LPGDBW Timing Wheel Crank Pulley Alignment Mark TDC Mark A MN A Magnetic Timing a KC YA Sensor Retaining Bolt Wheel Magnetic Sensor Magnetic Sensor Bracket Figure 5 Timing Wheel MAGNETIC SENSOR REPLACEMENT Figure 5 1 Disconnect the Magnetic Pickup sensor electrical connector 2 Remove the one 1 retaining bolt and re tain 3 Remove sensor Installation Procedure Remove any debris from the timing wheel 4 Install the Magnetic pickup into the brack et 5 Secure using one retaining bolt and tighten to specification Tighten 9 Nem 80 Ib in 6 Adjust air gap of Magnetic Pickup Refer to Magnetic Pickup Air Gap Adjustment Start engine 8 Check for any DTC codes and clear 9 Verify engine is in closed loop and no MIL lights are present SM20042002LPGDBW mi Pivot Bracket Timin Wh AR one Away From Align t
132. ine within the test parameters of DTC 143 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 147 DTC 211 Closed Loop Multiplier High LPG DK GRN ORN BLK LT GRN Sensor Ground PNK DK GRN To Engine Ground e To System Power Relay Conditions for Setting the DTC Heated Oxygen Sensor Check Condition Engine running Fault Condition Closed Loop multiplier out of range greater than 35 MIL Disabled Adaptive Enabled but not updated when Closed Loop is at limit Closed Loop Enabled Circuit description The HO2S sensor is used to determine if the fuel flow to the engine is correct by measuring the oxygen content in the exhaust gas The ECM uses this information to correct the fuel flow with the Closed Loop multiplier and the adaptive multiplier This fault sets if the Closed Loop multiplier exceeds the limits of normal operation and cannot correctly modify the fuel flow within its limits Diagnostic Aids Always diagnose any ECM codes that are present before beginning this diagnostic procedure Heated Oxygen sensor wires may be mis routed and contacting the exhaust manifold Vacuum leaks can cause a lean exhaust condition especially at light load and idle conditions Exhaust leaks can cause a lean exhaust condition especially at light load and idle conditions A poor ECU ground to the engine block or battery negative Problems with the
133. into the dipstick tube Remove the oil filler cap from the valve rocker arm cover Add the required amount of oil to bring the level up to but not over the FULL mark on the dipstick Reinstall the oil filler cap to the valve rocker arm cover and wipe any excess oil clean SM20042002LPGDBW Changing The Engine Oil When changing the oil always change the oil filter 1 Start the engine and run until it reaches normal operating temperature Change oil when engine is warm from operation as it flows more freely carrying away more impurities 2 Stop engine A WARNING Engine oil will be hot Use protective gloves to pre vent burns Engine oil contains chemicals which may be harmful to your health avoid skin contact 3 Remove drain plug and allow the oil to drain Remove and discard oil filter and it sealing ring 5 Coat sealing ring on the new filter with clean engine oil wipe the sealing surface on the filter mounting surface to remove any dust dirt or debris Tighten filter securely follow filter manufacturers instructions Do not over tighten 6 Check sealing ring on drain plug for any damage replace if necessary wipe plug with clean rag wipe pan sealing surface with clean rag and re install plug into the pan Tighten to specification Fill crankcase with oil Start engine and check for oil leaks Dispose of oil and filter in a safe manner SM20042002LPGDBW Fuel System Inspection And Maintena
134. is protection is important because of the very low voltage and current levels found in the electronic system 1 OPEN SECONDARY LOCK HINGE ON CONNECTOR FEMALE MALE CONNECTOR CONNECTOR A d J SECONDARY LOCK HINGE 2 REMOVE TERMINAL USING TOOL PUSH TO RELEASE TERMINAL TOOL J 28742 BT8234 A 3 CUT WIRE IMMEDIATELY BEHIND CABLE SEAL ash SEAL 4 REPLACE TERMINAL A SLIP NEW SEAL ONTO WIRE B STRIP 5 mm 2 OF INSULATION FROM WIRE C CRIMP TERMINAL OVER WIRE AND SEAL 5 PUSH TERMINAL AND CONNECTOR AND ENGAGE LOCKING TANGS 6 CLOSE SECONDARY LOCK HINGE FIGURE 4 WEATHER PACK TERMINAL REPAIR 1 I 2 ILL 3 TOOL 135689 OR BT 8446 4 CONNECTOR BODY 5 SEAL FIGURE 3 METRI PACK SERIES 150 TERMINAL REMOVAL SM20042002LPGDBW 65 Repair of a Weather Pack terminal is shown in Figure 3 23 Use tool J M28742 or BT8234 A to remove the pin and sleeve terminals If removal is attempted with an ordinary pick there is a good chance that the terminal will be bent or deformed Unlike standard blade type terminals these terminals cannot be straightened once they are bent Make certain that the connectors are properly seated and all of the sealing rings in place when connecting leads The hinge type flap provides a backup or secondary locking feature for the connector They are used to im prove the connector reliability by retaining the terminals if the small ter
135. is used to monitor incoming air temperature and the output in conjunction with other sensors is used to determine the airflow to the engine The ECM provides a voltage divider circuit so that when the air is cool the signal reads higher voltage and lower when warm The IAT is a calculated value based mainly on the IAT sensor at high airflow and influenced more by the ECT Engine Coolant Temperature at low airflow This fault will set if the Intake Air Temperature is greater than 210 degrees F after 120 seconds and engine RPM is greater than 1000 The MIL light will be on during this active fault and the engine 106 SM20042002LPGDBW DTC 114 IAT Higher Than Expected 2 Diagnostic Aids This fault will set when inlet air is much hotter than normal The most common cause of high inlet air temperature is a problem with the inlet air system Ensure that the air inlet is not obstructed modified or damaged Inspect the air inlet system for cracks or breaks that may allow unwanted under hood air in to the air inlet system Tf none of the above can be found Follow the diagnostic steps for DTC 112 IAT Low Voltage SM20042002LPGDBW 107 DTC 115 Oil Pressure Low ECM 5 volts LT GRN BLK Oil Pressure Voltage To Oil Pressure Switch Conditions for Setting the DTC Engine Oil Pressure low Check Condition Engine running for 15 seconds and RPM greater than 600 Fault Condition Open circuit voltage high M
136. it as 8 corrosion or contamination necessary Did you find a problem Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 209 Replace the TPS 1 Go to Step Is the replacement complete 9 Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 632 check for any stored codes Does the engine operate normally with no stored codes 210 SM20042002LPGDBW SM20042002LPGDBW 211 DTC 632 TPS 1 Signal Voltage Low Sensor Ground LT GRN RED 5 volts PPL LT BLUE c 49 mn BLK LT GRN Conditions for Setting the DTC Throttle Position Sensor 1 Check Condition Cranking or Running Fault Condition TPS sensor voltage less than 0 2 MIL On during active fault Power Derate 1 Low rev limit 1300 rpm Forced idle 700 rpm Circuit Description 212 The Electronic Throttle has two counter acting Throttle Position Sensors Two sensors are used for improved safety and redundancy The Throttle Position sensor uses a variable resistor to determine signal voltage based on throttle plate position and is located within the throttle Less opening
137. ity between ECT sensor Go to step connector signal circuit pin A and engine Repair the 7 ground circuit as Do you have continuity necessary Refer to Wiring Repairs in Engine Electrical connector signal pin ECT sensor ground Do you have continuity between them SM20042002LPGDBW 117 118 Replace ECM Refer to ECM replacement in the Engine Controls Section Is the replacement complete Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 122 check for any stored codes Does the engine operate normally with no stored codes Go to step 8 System OK Go to OBD System Check SM20042002LPGDBW SM20042002LPGDBW 119 DTC 123 ECT Higher Than Expected 1 YEL GRY Sensor Ground Conditions for Setting the DTC Engine Coolant Temperature Check Condition Engine Running Fault Condition Engine Coolant Temperature reading or estimate greater than 220 degrees F and engine RPM greater than 500 for 60 seconds MIL On during active fault and for 15 seconds after active fault Adaptive Disabled during active fault Closed Loop Enabled
138. ize any type of per manent antifreeze or any brand antifreeze solution that meets GM Specification 1825M or 1899M which will not damage aluminum parts Engine Electrical System Maintenance The engine electrical system incorporates computers to control certain functions of the equipment The electrical system connections and ground circuits require good connections Follow the recommended maintenance schedule in this section to maintain op SM20042002LPGDBW timum performance When inspecting the electrical system check the following e Check battery connection clean and in sure that connectors are tight e Check battery for cracks or damage to the case replace if necessary e Check Positive and Negative cables for corrosion rubbing chaffing and insure tight connections at both ends e Check engine wire harness for rubbing chaffing pinching and cracks or breaks in the wiring e Check engine harness connectors check to insure fitted and locked by pushing the connector together then pull on the con nector halves to insure they are locked e Check ignition coil wire for hardening cracking arcing chaffing separation split boot covers and proper fit e Check spark plug wires for hardening cracking chaffing separation split boot covers and proper fit e Replace spark plugs at the required inter vals per the recommended maintenance schedule e Check to insure all electrical components are securely mounte
139. jacent to a pulse wheel located on the crankshaft It determines crankshaft position by monitoring the pulse wheel The Crankshaft Position sensor is used to measure engine RPM and its signal is used to synchronize the ignition and fuel systems The ECM must see a valid Crankshaft position signal while running If no signal is present for 800ms or longer this fault will set SM20042002LPGDBW DTC 142 Crank Sync Noise Did you perform the On Board OBD Go to Step Goto OBD System Check System Check Section 2 Check to be sure that the ECM Go to Step Repair the ground terminal G1 to engine ground 3 circuit as is clean and tight necessary Is terminal G1 clean and tight Refer to Wiring Repairs in Engine Electrical 4 5 Key OFF Go to Step Go to Step Disconnect the CKP sensor connector 11 Using a DVOM check for voltage output from the CKP sensor while cranking the engine Do you have voltage output Key OFF Go to Step Repair the Disconnect ECM connector C001 5 circuit as Using a DVOM check for continuity necessary between CKP connector pin A and ECM Refer to connector pin 11 Wiring Do you have continuity between them Repairs in Engine Electrical Using a DVOM check for continuity Go to Step Repair the between CKP connector pin B and ECM 6 circuit as connector pin 12 necessary Do you have continuity between them Refer to Wiring Repairs in Engine Electrical e Inspect the CKP connector C011 pins fo
140. le restriction Inspect the exhaust system for damaged or collapsed pipes Inspect the muffler for signs of heat distress or for possible internal failure Check for possible plugged catalytic converter Refer to Restricted Exhaust System Diagnosis 47 Hard Start DEFINITION The engine cranks OK but does not start for a long time The engine does eventually run or may start but immediately dies Preliminary Checks Refer to Important Preliminary Checks Make sure the vehicle s operator is using the correct starting procedure Sensor Checks Check the Engine Coolant Temperature sensor with the scan tool Compare the engine coolant temperature with the ambient air temperature on a cold engine IF the coolant temperature reading is more than 5 degrees greater or less than the ambient air temperature on a cold engine check for high resistance in the coolant sensor circuit Refer to DTC 111 Check the Crankshaft Position CKP sensor Check the Throttle position TPS sensor Fuel System Checks Important A closed LPG manual fuel shut off valve will create an extended crank OR no start condition e Verify the excess flow valve the LPG manual shut off valve is not tripped Check mixer module assembly for proper installation and leakage Verify proper operation of the low pressure lock off solenoids Verify proper operation of the PTV and FTV Check for air intake system leakage between the mixer and the thro
141. lf test and the test fails When a DTC is set the ECM will illuminate the Malfunction Indicator Lamp on the instrument panel and save the code in memory The ECM will continue to run the self test unless the DTC is an oxygen sensor lean oxygen sensor rich or an internal ECM related DTC If the system continues to fail the test the lamp will stay illuminated and the DTC is current ACTIVE All DTC s are stored as historical faults until they are cleared All DTC s except the ECM related DTC s will automatically clear from memory if the DTC does not reset within 100 consecutive engine run cycles While a Diagnostic Trouble Code is current for a sensor the ECM may assign a default limp home value and use that value in its control algorithms All of the system diagnostic self tests run continuously during normal vehicle operation The Diagnostic Trouble Codes can be read by using either the MIL lamp or a laptop computer Refer to Using a Laptop Computer to Diagnose the Spectrum System and Using a Diagnostic Jumper to Diagnose the ECI System located in this section Diagnostic Trouble Codes can be cleared from memory with a laptop computer or by turning the ignition key to the OFF position and removing the system main power fuse F3 for 15 seconds If more than one DTC is detected always begin with the lowest number DTC and diagnose each problem to correction unless directed to do otherwise by the fault tree The DTC s are numbered in orde
142. lve 19 Check for leaks at the inlet and outlet fittings us ing a soapy solution or an electronic leak detec tor if leaks are detected make repairs Check coolant line connections to ensure no leaks are present 20 Start engine recheck for leaks at the regulator 21 Dispose of any drained material in safe and proper manner Air Fuel Mixer throttle Control Device Maintenance And Inspection A CAUTION The Air Fuel Mixer components have been spe cifically designed and calibrated to meet the fuel system requirements of the emission certified engine The mixer should not be disassembled or rebuilt If the mixer fails to operate or devel ops a leak the mixer should be replaced with the OEM recommended replacement parts When inspecting the mixer check for the following items e Check for any fuel leaks at the inlet fitting e Check the fuel inlet hose for cracking splitting or chaffing replace if any of these condition exist e Check to ensure the mixer is securely mounted e Check air inlet hose connection and insure clamp is tight check inlet hose for cracking split ting or chaffing replace if any of these condition exist Check air cleaner element according to the Recommended Maintenance Schedule found in this section Check fuel line to Throttle body mounted Fuel 15 Trim Valve FTV for cracking splitting or chaff ing replace if any of these condition exist e Check Throttle body return acti
143. m Go to Step Go to OBD Check 2 System Check Section 2 Intermittent Go to Step Key On Engine Running problem 3 DST Diagnostic Scan Tool connected in Go to Engine System Data Mode Electrical Run engine greater than 1500 rpm Intermittent section Does DST display system voltage less than 18 volts DVOM with engine speed greater than 1500 rpm Is it greater than 18 volts Check voltage at battery terminals with Go to Step Go to Step 4 5 6 B 6 System OK Go to OBD System Check Has the charging system been repaired 5 Replace ECM Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 262 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 171 DTC 511 COP Failure Microprocessor Conditions for Setting the DTC Engine Control Module Check Condition Key on Fault Condition Internal microprocessor error MIL On until code is cleared by technician Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Power Derate level 2 until fault is cleared manually
144. manufacturer Open Loop An operational mode during which control module memory information is used to determine air fuel ratio injection timing etc as opposed to actual oxygen sensor input Orifice A port or passage with a calibrated opening designed to control or limit the amount of flow through it Oscilloscope An instrument that converts voltage and frequency readings into traces on a cathode ray tube also see Cathode Ray Tube Oxides of Nitrogen Chemical compounds of nitrogen bonded to various amounts of oxygen Nox A chief smog form ing agent Oxygen Sensor An automotive fuel system that produces a signal in accordance with the oxygen content of the ex haust gas See Lambda Sensor Oxygenate MTBE ethanol and methanol Oxygenates are added to gasoline to increase the oxygen content and therefore reduce exhaust emissions Ozone A radical oxygen module O3 that is found in the upper atmosphere and filters out ultraviolet radiation from the sun Ground level ozone is formed by Nox during the formation of photochemical smog 6 SM20042002LPGDBW Particulates Microscopic pieces of solid or liquid substances such as lead and carbon that are discharged into the at mosphere by internal combustion engines Positive Crankcase Ventilation PCV An automotive emission control system designed to reduce hydrocarbon emis sions by routing crankcase fumes into the intake manifold rather than to the atmosphere Power Derate Le
145. maximum throttle position will be 20 This is enforced until the fault is manually cleared SM20042002LPGDBW DTC 515 Flash Checksum Invalid Did you perform the On Board OBD System Check Key On Engine Running DST Diagnostic Scan Tool connected in System Data Mode Clear system fault code Does DTC 515 reset with the engine idling Check all ECM power and ground circuits Refer to power and ground distribution in engine electrical section Are the power and ground circuits Ok Replace ECM Is the replacement complete Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 515 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW Go to 2 Go to OBD System Check Section Intermittent problem Go to Intermittent section Go to Step 3 Go to Step 4 Repair the circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step 5 Go to OBD System Check E 181 DTC 516 Ram Failure Microprocessor Conditions for Setting the DTC Random Access Memory Check Condition Key
146. minal lock tangs are not positioned prop erly Weather Pack connections cannot be replaced with standard connections Instructions are provided with Weather Pack connector and terminal packages 66 SM20042002LPGDBW SM20042002LPGDBW 67 MAIN WIRING HARNESS 12048074 TERMINAL 12052634 LOCK c005 RED WHITE 18 ORANGE BLUE 16 COO1 PED 12009442 SEAL ECM IMP PTV 211 PC 5625 0 009 CONNECTOR 211 567007 LOCKING CAM 211 A 56 0008 COVER 211 CC2S 1120 TERM 18 ORANGE BLUE 16 16 17 BROWN GREEN 18 30 LT BLUE WHITE 18 N gt IN je INJ2 TR vo Ste MiP lt LN 31 _ YELLOW GRAY 18 etowe 36 _ DK BLUE YELLOW 18 POWER GROUND ESAT L POWER GROUND MACKIE IM ARA 49 BLACKLTGREEN T6 nn 50 LT GREEN RED 18 ww 21_PINKITAN 18 55 DKGREENORANGE 601 41 KNK PE Pun 11 GRAY BROWN 20 GAWK 12 PURPLE ORANGE 20 RSA CAM a LTGREEN RED 18 al m TANTS WART 22 RED TAN 16 BLACK LT GREEN 18 na 23 RED TAN 16 STARTER LOCKOUT ONS FUEL LOCKOFF gt eM 0 10 wrote 18 ma PURPLELTBLUE 18 m S4 LTRLUEDKBIUE T8 A 24 PRKWHITETS pes 25 TANJORANGE 18 57 DK GREEN WHITE TE 56 i 26 LTBLUE BLACK18 7 AUXANAPD2 PRAE 2 pumspknueis FUEL SELECT 42 AUX ANA PU s
147. n Engine Electrical Replace ECM Go to Step Is the replacement complete 5 Remove all test equipment except the System OK Goto OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 514 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 179 DTC 515 Flash Checksum Invalid Microprocessor Conditions for Setting the DTC 180 Engine Control Module Check Condition Key on Fault Condition Internal microprocessor error MIL On until code is cleared by technician Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Power Derate level 2 until fault is cleared manually Circuit Description The ECM has checks that must be satisfied each time an instruction is executed Several different things can happen within the microprocessor that will cause this fault The ECM will reset itself in the event this fault is set and the MIL will be on until the code is cleared This fault should be erased after diagnosis by removing battery power It will not self erase During this active fault Power Derate level 2 will be enforced When this is enforced
148. n Vehicle IMPCO Imperial Machine Products Company IMPCO Technologies Inc A manufacturer of both LPG and Gasoline fuel systems Impedance A form of opposition of AC current flow resistance measured in ohms Insulation A nonconductive material used to cover wires in electrical circuits to prevent the leakage of electricity and to protect the wire from corrosion SM20042002LPGDBW 5 Intercept An electrical term for a type of splice where the original circuit is interrupted and redirected through another circuit ITK IMPCO Test Kit Knock Sound produced when an engine s air fuel mixture is ignited by something other than the spark plug such as a hot spot in the combustion chamber Can be caused by a fuel with an octane rating that is too low or maladjusted ignition timing Also called detonation or ping Lambda Sensor A feedback device usually located in the exhaust manifold which detects the amount of oxygen present in exhaust gases in relation to the surrounding atmosphere LDV Light Duty Vehicle Lean Mixture An air to fuel ratio above the stoichiometric ratio too much air LEV Low Emission Vehicle Limp in or Limp home This term is used to describe the drivability characteristics of a failed computer system Liquified Petroleum Gas LPG A fuel commonly known as propane consisting mostly of propane C3H8 derived from the liquid components of natural gas stripped out before the gas enters the pipeline and the
149. nance Schedule In severe operating condition more frequent replacement of the filter may be neces sary Electric Lock Off The Electric Lock Off device is an integrated assembly The electric lock assembly is a 12 volt normally closed valve The solenoid is mounted to the valve body When energized the solenoid opens the valve and allows the Propane fuel to flow through the device The valve opens during cranking and run cycles of the engine The lock off supply voltage is controlled by the engine module ECM Inlet fitting to Electric 7 Lock off _ Electric Lockoff pe lt de Adapter Lockoff to LPR Low Pressure Regulator LPR Figure 4 Electric Fuel Lock Off 24 Low Pressure Regulator LPR The LPR is a combination vaporizer pressure regulating device The LPR is a negative pres sure two stage regulator that is normally closed when the engine is not running When the en gine is cranking or running a partial vacuum is created in the fuel line which connects the regu lator to the mixer This partial vacuum opens the regulator permitting fuel to flow to the mixer Propane fuel enters the primary port of the LPR and passes through the primary jet and into the primary exchanger chamber As the propane passes through the heat exchanger the fuel expands and creates pressure inside the cham ber The pressure rises as the fuel expands when the pressure rises above 10 34 kpa 1 5 psi sufficient pressure is e
150. nce Propane Fuel System The Propane fuel system installed on this industrial engine has been designed to meet the emission standard applicable for this equipment for 2004 mod el year To ensure compliance to these standards follow the recommended maintenance schedule con tained in this section Inspection And Maintenance Of The Fuel Storage Cylinder The fuel storage cylinder should be inspected daily or at the beginning of each operational shift for any leaks external damage adequate fuel supply and to insure the manual service valve is open Fuel stor age cylinders should always be securely mounted inspect the securing straps or retaining devices for damage insure that all locking devices are closed and locked Check to insure that the fuel storage cylinder is positioned with the locating pin in the tank collar on all horizontally mounted cylinders this will insure the proper function of the cylinder relief valve When refueling or exchanging the fuel cylinder check the quick fill valve for thread damage Insure the o ring is in place check the o ring for cracking chunk ing or separation replace if damaged before filling Check the service line quick coupler for any thread damage Insure the o ring is in place check the o ring for cracking hardening chunking or separation Replace if damaged When refueling the fuel cylinder wipe clean both the female and male connection with a clean rag prior to filling This will p
151. ndicate 220 system degrees F or greater Verify ECT circuit function Follow diagnostic test procedure for DTC 122 ECT Low Voltage SM20042002LPGDBW 121 124 ECT Higher Than Expected 2 YEL GRY Sensor Ground Conditions for Setting the DTC Engine Coolant Temperature Check Condition Engine Running Fault Condition Engine Coolant temperature reading or estimate greater than 235 degrees F and engine RPM greater than 500 for 60 seconds MIL On for active fault and for 15 seconds after active fault Adaptive Enabled Closed Loop Enabled Engine Shut Down Circuit Description 122 The Engine Coolant Temperature sensor is a thermistor temperature sensitive resistor located in the engine coolant The ECT Engine Coolant Temperature sensor that is located in the coolant near the thermostat The ECT is used for engine airflow calculation ignition timing control fuel enrichment to enable certain features and for engine protection The ECM provides a voltage divider circuit so when the sensor reading is cool the signal reads higher voltage and lower when warm This fault will set 1f coolant temperature reaches 235 degrees F and engine RPM exceeds 500 rpm then engine will shut down SM20042002LPGDBW DIS 124 ECT Higher Than Expected 2 Did you perform the On Board OBD Go to to Sio Go to OBD System Check 2 System Check Section Key On Go to Step Intermittent DS
152. ndition Drive the vehicle at the speed of the complaint Monitoring the oxygen sensors will help identify the problem Check for a sticking mixer air valve Verify proper operation of the PTV and FTV Perform a cylinder compression test Refer to Engine Mechanical in the Service Manual Check the LPR fuel pressure Refer to the LPG Fuel System Diagnosis Check mixer module assembly for proper installation and connection 60 SM20042002LPGDBW Ignition System Checks Check for the proper ignition output voltage using the spark tester J26792 or the equivalent Verify that the spark plugs are correct for use with LPG R46TS Check the spark plugs Remove the plugs and inspect them for the following conditions Wet plugs Cracks Wear Improper gap Burned electrodes Blistered insulators Heavy deposits Check the spark plug wires by connecting an ohmmeter to the ends of each wire in question If the meter reads over 30 000 ohms replace the wires Additional Checks Important The LPG Fuel system works on a fumigation principle of fuel introduction and is more sensitive to intake manifold leakage than the gasoline fuel supply system Check for vacuum leaks Vacuum leaks can cause a higher than normal idle and low throttle angle control command Check the ECM grounds for being clean tight and in their proper locations Check the battery cables and ground straps They should be clean and secure Erratic voltage may cause
153. ng clean tight and in their proper locations Check the generator output voltage If all procedures have been completed and no malfunction has been found review and inspect the following items Visually and physically inspect all electrical connections within the suspected circuit and or systems Check the scan tool data 57 Poor Fuel Economy DEFINITION Fuel economy as measured by refueling records is noticeably lower than expected Also the economy is noticeably lower than it was on this vehicle at one time as previously shown by an by refueling records Preliminary Checks Refer to Important Preliminary Checks e Check the air cleaner element filter for dirt or being plugged e Visually Physically check the vacuum hoses for splits kinks and proper connections e Check the operators driving habits for the following items Is there excessive idling or stop and go driving Are the tires at the correct air pressure Are excessively heavy loads being carried Is their often rapid acceleration e Suggest to the owner to fill the fuel tank and to recheck the fuel economy e Suggest that a different operator use the equipment and record the results Fuel System Checks e Check the LPR fuel pressure Refer to LPG Fuel System Diagnosis e Check the fuel system for leakage Sensor Checks Check the Temperature Manifold Absolute Pressure TMAP sensor Ignition System Checks Verify that the spark plugs
154. ns for Setting the DTC Foot Pedal Position Check Condition Key On Fault Condition FPP sensor voltage less than 0 200 MIL On during active fault Power Derate 1 Low rev limit 1300 rpm Force Idle 700 rpm Circuit Description The Foot Pedal Position sensor uses a variable resistor to determine signal voltage based on pedal position Less depression of pedal results in lower voltage and greater depression results in higher voltage This fault will set if voltage is less than 0 2 volts at any operating condition while the key is on If the voltage is less than 0 2 then FPP is considered to be out of specifications At this point the ECM does not have a valid signal and must therefore enforce the low rev limit and Power Derate level 1 When these are enforced the maximum throttle position is 50 and the maximum engine speed is 1300 RPM The Low Rev Limit is enforced for the remainder of the key on cycle to 700 rpm Rev limit is still enforced if the active fault is no longer present 200 SM20042002LPGDBW DTC 612 FPP Voltage Low Values Yes No Did you perform the On Board OBD GotoStep Goto OBD System Check 2 System Check Section Key ON Engine OFF Go to Step Go to Step DST Diagnostic Scan Tool connected in 7 3 System Data Mode Does the DST display FPP voltage of 0 2 volts or less with the foot pedal in the idle position e Slowly depress FP while observing FPP Go to step Intermittent voltage
155. o lift against the air valve spring The amount of AVV generated is a di rect result of the throttle position At low engine 26 speed the air valve vacuum is low and the air valve position is low thus creating a small ven turi for the fuel to flow As the engine speed increase the AVV increases and the air valve is lifted higher thus creating a much larger venturi This air valve vacuum is communicated from the mixer venture to the LPR secondary cham ber via the low pressure fuel supply hose As the AVV increases in the secondary chamber the secondary diaphragm is drawn further down forcing the secondary valve lever to open wider The mixer is equipped with a low speed mixture adjustment which is retained in a tamper proof housing The mixer has been preset at the fac tory and should not require any adjustment In the event that the idle adjustment should need to be adjusted refer to the Fuel System Repair section of this manual The mixer is mounted into the air stream utiliz ing an adapter which contains the Fuel Trim Valve FTV The FTV is utilized to assist with SM20042002LPGDBW fuel control while the engine is operating The FTV is a 12 volt normally closed electric valve and is connected to the LPR by a fuel line The FTV normally receives a pulse from the ECM which causes the FTV to be cycled open and closed to allow additional fuel to be supplied to the air stream above the throttle plate During normal closed loop op
156. oltage Does the DST display BP pressure of 16 00 psia or greater e Check for continuity between TMAP sensor connector ground pin A and ECM connector pin 49 Do you have continuity between them Key OFF Goto step Repair the Disconnect ECM connector 10 circuit as e Check for continuity between TMAP necessary sensor connector pin C and ECM Refer to connector pin 50 Wiring Do you have continuity between them Repairs in Engine Electrical Repair the Go to Step circuit as 11 necessary Refer to Wiring Repairs in Engine Electrical Check for continuity between TMAP sensor connector 5 volt reference signal pin C and engine ground Do you have continuity 136 SM20042002LPGDBW Inspect TMAP AND ECM connectors pins for corrosion contamination or mechanical damage Any problems found Repair the Go 3a circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to step 17 Go a 2 Repair the circuit as necessary Refer to Wiring Repairs in Engine Electrical Replace ECM Refer to ECM replacement in the Engine Controls Section Is the replacement complete e Disconnect ECM connector e Check for continuity between TMAP sensor connector pin D and ECM pin 33 Do you have continuity between them e Inspect ECM connector and wire harness connector pins for corrosion contamination or mechanical damage Any problems found Repair the Go Eug circuit as necessary Refer to Wi
157. ome on with the vehicle key on engine off repair it as soon as possible Once the engine is in start or run mode the lamp should go off If the lamp illuminates while the engine is in the start or run mode a current Diagnostic Trouble Code may be set Always use the OBD System Check chart on the next page of this manual to verify proper MIL operation before proceeding with a DTC diagnostic code repair 92 SM20042002LPGDBW OBD System Check Value s Yes No Go to Step Go to Step 2 3 MIL is Go to Step working 10 properly OBD System Check is complete Go Mak Repair MIL voltage source Refer to OEM body and chassis wiring diagrams Go to step Go 2 2 1 Go ie ae Go to Step 8 Repair the Go i circuit as necessary Refer to Wiring Repairs in Engine Electrical 2 Key Engine OFF Does the MIL illuminate Start the engine Does the MIL lamp turn off Key ON engine OFF Check for voltage between MIL power source and engine ground Do you have voltage Replace MIL lamp Did that solve the problem Key OFF Disconnect ECM wire harness connector C001 Using a DVOM check for continuity between MIL side of connector C022 and ECM terminal 26 Do you have continuity Inspect the MIL lamp socket connector C022 and ECM terminal 26 for damage corrosion or contamination Did you find a problem 7 Replace ECM Is the replacement complete SM20042002LPGDBW 93 94 Back pro
158. on Tighten 9 Nem 80 Ib in 4 Remove the feeler gauge 5 Start engine 6 Check for any DTC codes and clear 7 Verify engine is in closed loop and MIL lights are present SM20042002LPGDBW 263 264 SM20042002LPGDBW
159. on to ensure throttle shaft is not sticking repair if necessary e Check FTV electrical connection to ensure con nector is fully seated and locked e Check for leaks at the throttle body and intake manifold Exhaust System And Catalytic Converter Inspection And Maintenance The exhaust system on this emission certified engine contains an Exhaust Gas Oxygen Sensor EGO which provides feed back to the ECM on the amount of oxygen present in the exhaust stream af ter combustion The measurement of oxygen in the exhaust stream is measured in voltage and sent to the ECM The ECM then makes corrections to the fuel air ratio to ensure the proper fuel charge and optimum catalytic performance Therefore it is im portant that the exhaust connections remain secured and air tight A CAUTION The EGO sensor is sensitive to silicone or silicone based products Do not use silicone sprays or hoses which are assembled using silicone lubricants Silicone contamination can cause severe damage to the EGO When inspecting the Exhaust system check the fol lowing e Check the exhaust manifold at the cylinder head for leaks and that all retain bolts and shields if used are in place e Check the manifold to exhaust pipe fasteners to ensure they are tight and that there are no ex haust leaks repair if necessary Check EGO electrical connector to ensure con nector is seated and locked check wires to en sure there is no cracking splits ch
160. onmental conditions Failure to follow this recommendation may result in a false DTC diagnosis SM20042002LPGDBW DTC 721 Transmission Over Temperature Step Action 7 Value s Yes No Did you perform the On Board OBD Go to Step Goto OBD 2 System Check Section System Check Go to step Perform the 3 Diagnostic Aids check for DTC 721 Did you perform the Diagnostic Aids check for DTC 721 e Verify transmission relay lamp circuit is in proper working order and not shorted to ground Is the transmission relay lamp circuit ok Go to Step Repair the 5 circuit as required See chassis electrical system section Go to Step 6 e Replace transmission temperature switch B i 3 Key Off Repair the Go to Step Disconnect ECM connector C001 shorted 4 Disconnect transmission temperature a ui switch connector CO20 9 Using a high impedance DVOM Refer to check for continuity between ECM pin Wiring 36 and engine ground Repairs in Engine Do you have continuity Electrical mE Is the replacement complete SM20042002LPGDBW 249 System OK Go to Step 7 Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature running the transmission to similar conditions whe
161. onments The recommended schedule is a rec ommended guide line for the owner and servicing agency to follow however certain environmental op erating conditions may require more frequent inspec tion and maintenance In addition the owner may have installed additional equipment to the equipment which may also increase the requirements for ser vice on certain components Therefore the owner and servicing agent should review the operating condition of the equipment and determine if more frequent inspections and maintenance cycles maybe required A WARNING The engine installed in this equipment may use one or both accessory drive belt configurations The drive belt may be incorporated to drive the water pump alternator and addition pumps or devices It is important to note the drive belt is an integral part of the cooling and charging system and should be in spected at a minimum according to the maintenance schedule in this section and in extremely hot and dirty environments more often When inspecting the belts check for Cracks e Chunking of the belt Splits Material hanging loose from the belt e Glazing hardening If any of these conditions exist the belt should be re placed with an OEM replacement belt V Belt Systems Check the belt tension by pressing down on the midway point of the longest stretch between two pulleys The belt should not depress beyond 13mm 1 2 inch If the depression is more than allowable 1
162. ool with 2 holes in timing wheel and the crank pulley Figure 6 Removing Timing Wheel TIMING WHEEL REPLACEMENT Figure 6 1 Remove the four retaining bolts and lock washer and retain 2 Remove the timing wheel Installation Procedure Remove any debris from the magnetic sensor 3 Loosen the top and bottom Sensor Bracket bolts slightly and pivot the bracket away from the timing wheel 4 Locate the timing wheel to the pulley by aligning the slot in the timing wheel with the TDC mark on the crankshaft pulley 5 Re install the 4 retaining bolt and lock washers Install hand tight only 6 Insert the timing wheel installation tool into the timing wheel Hold tool against the face of the crank pulley Bolts can be used to 261 10 11 12 13 hold the tool place if necessary Center the timing wheel to the pulley Timing wheel should have very little Install the four 4 bolts and tighten to specification Tighten 9 Nem 80 Ib in Remove the timing wheel tool Adjust air gap of Magnetic Pickup Refer to Magnetic Pickup Air Gap Adjustment Start engine Check for any DTC codes and clear Verify engine is in closed loop and no MIL lights are present Timing Wheel Locator Magnetic Pick up Timing Wheel e ER Manual Marks at 12 00 3 00 6 00 and 9 00 Timing wheel Mounting Bolts Figure 7 Installing Timing Wheel TIMING WHEEL REPLACEMENT WITHOUT SPECIAL TOOL Figure 6 1 2
163. operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 636 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 231 DTC 637 Throttle Unable To Open TPS 1 Signal Sensor Ground TPS 2 Signal 5 VOLTS Conditions for Setting the DTC Throttle Position Sensor Check Condition Cranking or Running Fault Condition Throttle command is 20 more than throttle position MIL On during active fault Engine Shut Down Circuit Description 232 There are 2 Throttle Position Sensors located within the throttle which use variable resistors to determine signal voltage based on throttle plate position TPS1 will read low voltage when closed and TPS2 will read high voltage when closed The TPS1 and TPS2 percentages are calculated from these voltages Although the voltages are different the calculated values for the throttle position percentages should be very close to the same The TPS values are used by the ECM to determine if the throttle is opening as commanded This fault will set if the throttle command is 2096 or more than the actual throttle position During this active fault the MIL light will turn on and the engine will shut down SM20042002LPGDBW DTC 637 Throttle Unable to Open Step Action Value s Yes No Did you perform the On Board
164. or necessary positive and D for negative check for Refer to voltage Wiring Do you have voltage Repairs in Engine Electrical Key OFF Repair the Go a NU Disconnect HO2S sensor wire harness circuit as connector necessary Disconnect ECM wire harness connector Refer to Key ON Wiring R Using a DVOM check for voltage at HO2S R Jee connector signal pin B and engine ground Electrical Do you have voltage BN SM20042002LPGDBW 159 Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 243 check for any stored codes Does the engine operate normally with no stored codes 160 SM20042002LPGDBW SM20042002LPGDBW 161 DTC 244 Adaptive Learn Low LPG DK GRN ORN BLK LT GRN Sensor Ground PNK DK GRN To Engine Ground be p To System Power Relay Conditions for Setting the DTC Heated Oxygen Sensor Check Condition Engine running Fault Condition Adaptive multiplier out of range at limit of 30 MIL Disabled Adaptive Enabled Closed Loop Enabled Circuit Description The HO2S sensor is used to determine if the fuel flow to th
165. ors are used for improved safety and redundancy The Throttle Position sensor TPS2 uses a variable resistor to determine signal voltage based on throttle plate position and is located within the throttle Less opening results in higher voltage and greater opening in lower voltage The TPS value is used by the ECM to determine if the throttle is opening as commanded This fault will set if voltage is above 4 8 volts at any operating condition while the engine is cranking or running Power derate 1 will be enforced limiting the throttle to 50 maximum Low rev limit and forced idle will also be enforced during this fault SM20042002LPGDBW DTC 633 TPS 2 Signal Voltage High Step Value s Yes No Did you 191 the On Board System i Go to OBD 2 System Check Section e Key ON Engine OFF Go to Step Go to Step e DST Diagnostic Scan Tool connected in 4 3 DBW Drive by Wire throttle test mode Does the DST display TPS 2 voltage of 4 8 volts or greater with the throttle closed e Slowly depress Foot Pedal while Go gt gt Intermittent observing TPS 2 voltage problem Does TPS 2 voltage ever exceed 4 8 volts Go to Intermittent section e Key OFF e Disconnect electronic throttle connector e Key ON Does DST display TPS 2 voltage less than 0 2 volts Replace ECM Is oie replacement complete 7 Back probe sensor ground circuit at the ECM side of the wire harness pin 49 with Go Go y Sr Key OFF
166. ostic code and turn on the MIL light in the dash A CAUTION The Heated Exhaust Gas Oxygen Sensor HEGO is an emissions control component If the HEGO fails to operate replace only with SM20042002LPGDBW INPUTS 02 gt Throttle ENGINE CONTROL MODULE Coolant Temperature Air Temperature gt Manifold Absolute Pressure Battery Foot Pedal Position gt LPG ECM OUTPUTS Throttle Control Pressure Trim Valve Fuel Trim Valve 5 Electric Lockoff Valve Governor Speed Control Timing Ignition Gauges Malfunction Indicator Lamp Figure 10 Engine control unit ECM an OEM replacement part The HEGO sen sor is sensitive to silicone and silicone based products and can become contaminated Avoid using silicone sealers or hoses treated with sili cone lubricant in the air stream or fuel supply lines SM20042002LPGDBW Figure 11 Exhaust Gas Oxygen Sensor EGO 29 Temperature Manifold Absolute Pressure Sensor TMAP The ECM receives signal from sensors mounted to the engine and fuel system to control engine operation and emission control The TMAP is a dual sensor mounted in the air
167. p Enabled Engine Shut Down Circuit description This fault will set anytime the engine RPM exceeds 4100 for 2 seconds or more continuously When these conditions are met the ECM will shut off spark to the engine This is to help prevent engine or equipment damage The MIL will be on during this active fault and the engine will shut down 246 SM20042002LPGDBW DTC 653 Spark Rev Limit Step Action 7 Value s No Did you perform the On Board OBD System Go to Step Go to OBD Check 2 System Check Section e Key ON Engine OFF Go to Step Go to Step 3 4 e DST in Active Fault Mode Are any other DTC codes present with DTC 651 Go to step 4 Go to Step Go to Step 5 6 e Replace ECM with correct Service Part Go to Step Number 9 Is the replacement complete e Diagnose any other DTC codes before proceeding with this chart Have any other DTC codes been diagnosed and repaired 4 e Check the Service Part Number on the ECM to ensure correct calibration is in use Is the Service Part Number Correct e Check the mechanical operation of the throttle Is the mechanical operation of the throttle OK e Correct mechanical operation of the throttle Refer to Engine amp Component R amp R Section 1E Has the mechanical operation of the throttle been corrected e Check engine for large manifold vacuum leaks Refer to Fuel Systems Section 1B Symptom Diagnostics Did you find and correct the vacuum leak
168. p connectors for damage corrosion or circuit as 8 contamination necessary Were any problems found Refer to Wiring Repairs in Engine Electrical 98 SM20042002LPGDBW SM20042002LPGDBW 99 DTC 112 IAT Low Voltage TMAP SENSOR Conditions for Setting the DTC Intake Air Temperature Check Condition Engine Cranking or Running Fault Condition IAT Sensor Voltage less than 0 05 MIL On during active fault and for 2 seconds after active fault Adaptive Disabled during active fault Closed Loop Enabled and allowed to stay at limit if required but will then also set the limiting fault Circuit Description The TMAP is a combined IAT Intake Air Temperature and MAP Manifold Absolute Pressure sensor A temperature sensitive resistor is used in the TMAP located in the intake manifold of the engine It is used to monitor incoming air temperature and the output in conjunction with other sensors is used to determine the airflow to the engine The ECM provides a voltage divider circuit so that when the air is cool the signal reads higher voltage and lower when warm The IAT is a calculated value based mainly on the IAT sensor at high airflow and influenced more by the ECT Engine Coolant Temperature at low airflow This fault will set if the signal voltage is less than 0 05 volts anytime the engine is cranking or running The ECM will use the default value for the IAT sensor in the event of this fault 100 SM20042002LPGDBW D
169. p Go to Step circuit pin B with a test light connected to 12 14 battery voltage Does the test light come on Key OFF Repair the Go to step Disconnect ECM wire harness connector circuit as 13 Inspect the ECM wire harness connector necessary terminals for damage corrosion or Refer to contamination Wiring Do you have voltage between them Repairs lem Did you find a problem in Engine Electrical Replace FPP sensor Go to step Is the replacement complete 15 198 SM20042002LPGDBW EIN __ _Value s _ __Yes__ Key OFF Go to Step Repair the Disconnect ECM connector 10 circuit as Check continuity between FPP sensor necessary connector ground pin B and ECM Refer to connector FPP sensor ground pin 49 Wiring Do have continuity between them sepals in Engine Electrical Remove all test equipment except the System OK Goto OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 611 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 199 DTC 612 FPP Low Voltage FPP LT GRN RED DK BLUE BLK LT GREEN Sensor Ground ECM Conditio
170. per sealing if damage replace e Check for coolant leaks at the radiator tank seams and inlet joints repair or replace as necessary e Check for leaks at the radiator hose connections tighten hose clamps if necessary Check Radiator hoses for swelling SM20042002LPGDBW separation cracks deterioration in the hoses or hardening if any of these conditions exist the hose should be replaced with the OEM replacement parts Check coolant level if low add with 50 50 mixture Do not add plain water Replace coolant per the recommended schedule at the end of this section CHECKING THE COOLANT LEVEL A WARNING Do not remove the cooling system pressure cap when the engine is hot Allow the en gine to cool and then remove the cap slowly allowing pressure to vent Hot coolant un der pressure may discharge violently 1 Check coolant level in coolant recovery tank Add specified coolant as required The engine manufacturer and the fuel system sup plier do not recommend the use of stop leak addi tives to repair leaks in the cooling system If leaks are present the radiator should be removed and repaired If the radiator requires repair insure that the radiator core repairs did not result in a significant reduction in the cooling capacity of the radiator The engine manufacturer recommends the cooling system be filled with a 50 50 mixture of ethelyene glychol anitfreeze and water This GM industrial engine can util
171. performance and driveability After operating the engine within the test parameters of DTC 511 check for any stored codes Does the engine operate normally with no stored codes SM20042002LPGDBW 173 DTC 512 Invalid Interrupt Microprocessor Conditions for Setting the DTC Engine Control Module Check Condition Key on Fault Condition Internal microprocessor error MIL On until code is cleared by technician Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Power Derate level 2 until fault is cleared manually Circuit Description The ECM has checks that must be verified each time an instruction is executed Several different things can happen within the microprocessor that will cause this fault The ECM will reset itself in the event this fault 15 set and the MIL will be on until the code 15 cleared This fault should be erased after diagnosis by removing battery power It will not self erase During this active fault Power Derate level 2 will be enforced When this is enforced maximum throttle position will be 20 This is enforced until the fault is manually cleared 174 SM20042002LPGDBW DTC 512 Invalid Interrupt Did you perform the On Board OBD Go to OBD System Check 2 System Check Section Key On Engine Running Go to Step Intermittent DST Diagnostic Scan Tool connected in 3 problem System Data Mode Go to Clear system fault code Intermittent Does DTC 512 reset
172. pulses increases or decreases fuel delivery ENGINE Input Exhaust Gas Oxygen Sensor HEGO to ECM T to the engine ECM Calaculates the change and commands PTV OR FTV signals to increase or decrease Figure 15 Propane Closed Loop Control Schematic present in the exhaust gases after combus tion The correct air fuel ratio is necessary to maintaining proper temperature in the catalyst for conversion of the unburned gases after combustion and supplying sufficient power for engine operation Closed Loop Control System Closed Loop control is the term used to de scribe the strategy used by the ECM to maintain proper tail pipe emission The ECM utilizes the input of the sensors in the system to adjust air fuel ratio The HEGO provides a signal to the ECM which indicates the amount of oxygen SM20042002LPGDBW 31 32 SM20042002LPGDBW SM20042002LPGDBW SECTION 1B1 LPG FUEL SYSTEM DIAGNOSTICS 33 Coolant Inlet Fitting Secondary Test Port Cap Primary Test Port Fitting Je Retaining Pins LPG Fuel System Diagnosis Fuel System Description The Engine Control Module ECM receives in formation from various engine sensors in order to control the operation of the fuel control sole noid valves FTV and the low pressure lock off LPL solenoid The LPL solenoids prevent fuel flow unless the engine is cranking or running LPG is stored in
173. r Using a DVOM check for continuity between FPP sensor connector 5 volt reference pin A and ECM connector 5 volt reference pin 50 Do you have continuity between them e Using a DVOM check for continuity between ECM connector 5 volt reference pin 50 and ECM sensor ground pin 49 Do you have continuity between them Repair the Go to Step circuit as 13 necessary Refer to Wiring Repairs in Engine Electrical Repair the Go to Step circuit as 17 necessary Refer to Wiring Repairs in Engine Electrical e Inspect FPP and ECM connector terminal terminals for damage corrosion or contamination Any problems found Using A DVOM check for continuity Repair the Go to Step between ECM 5 volt reference pin 50 and circuit as 12 engine ground necessary Do you have continuity between them Refer to Wiring Repairs in Engine Electrical 202 SM20042002LPGDBW Go to Step Repair the 15 circuit as necessary Refer to Wiring Repairs in Engine Electrical Repair the Go to Step circuit as 16 necessary Refer to Wiring Repairs in Engine Electrical Using a DVOM check for continuity Repair the Go to Step between ECM FPP signal pin 38 and circuit as 13 ECM connector FPP sensor ground pin necessary 49 Refer to Do you have continuity between them Wiring Repairs in Engine Electrical Key OFF Disconnect ECM wire harness connector C001 Using a DVOM check for continuity between FPP connector signal pin
174. r Repair the Go to Step damage corrosion or contamination circuit as 7 Did you find a problem necessary Refer to Wiring Repairs in Engine Electrical SM20042002LPGDBW 141 Inspect the ECM connector C001 pins 11 and 12 for damage corrosion or contamination Did you find a problem Repair the Go to step Circuit as 8 necessary Refer to Wiring Repairs in Engine Electrical Using a DVOM check for continuity Repair the Go to Step between ECM connector pins 11 and 12 shorted 10 to engine ground circuit as Do you have continuity necessary Refer to Wiring Repairs in Engine Electrical Replace CKP sensor 10 e Replace ECM e 15 the replacement complete 16 11 Key OFF Repair the Go to Step Inspect the pulse wheel and CKP distributor as 12 sensor for mechanical damage necessary corrosion or contamination Refer to Did you find a problem Engine Repairs in Engine Section 12 Check the CKP pulse wheel to sensor 030 to Go to step Go to Step air gap 040 inches 13 14 Is the air gap correct 13 Check CKP for excessive movement Go to Step Go to Step or broken mounting bracket Does the 15 9 CKP show excessive movement on the bracket 14 030 to Go to Step Reset air gap to the correct 040 inches 16 specification Is the gap now set to the correct specification 142 SM20042002LPGDBW Go to Step 16 Replace CKP sensor bracket Go to Step Is the replacement complete 16
175. r arms Worn camshaft lobes Broken or weak valve springs e Check the intake and exhaust manifold passages for casting flash SM20042002LPGDBW 51 Fuel System Checks Check the fuel system plugged fuel filter low fuel pressure etc Refer to LPG Fuel System Diagnosis Check the condition of the wiring to the low pressure lock off solenoid Additional Check Check for Electromagnetic Interference EMI EMI on the reference circuit can cause a missing condition Monitoring the engine RPM with a scan tool can detect an EMI A sudden increase the RPM with little change in the actual engine RPM indicates EMI is present If the problem exists check the routing of the secondary wires and the ground circuit 52 SM20042002LPGDBW Hesitation Sag Stumble DEFINITION The vehicle has a momentary lack of response when depressing the accelerator The condition can occur at any vehicle speed The condition may cause the engine to stall if it s severe enough Preliminary Checks Refer to Important Preliminary Checks Fuel System Checks Check the fuel pressure Refer to LPG Fuel System Diagnosis Check for low fuel pressure during a moderate or full throttle acceleration If the fuel pressure drops below specification there is possibly a faulty low pressure regulator or a restriction in the fuel system Check the Manifold Absolute Pressure MAP sensor response and accuracy Check LPL electrical connection Check
176. r of importance Having DTC 112 and DTC 122 both concerning the oxygen sensor is possible By repairing DTC 112 first the problem causing the DTC 122 may also be corrected SM20042002LPGDBW 83 DIAGNOSTIC COMMUNICATION ERROR The ECM 5 volt reference circuit powers the Spectrum diagnostic link cable In the event that the 5 volt reference signal is open or shorted to ground you will not be able to connect to the system If you are unable to connect follow the quick checks listed below Be sure you are using the correct password and latest software for the system you are connecting to Check the ECM system power and ground circuits Refer to DTC 261 for the power schematic Also check for 12 switched power at ECM pin 21 with the ignition key on Check for power at the DLC connector for 5 volts between pins C LT GRN RED and pin D BLK with the ignition key in the on position You may still be able to retrieve a code using the blink code function if none of the above recommendations prove useful In the event of a 5 volt reference signal malfunction DTC 531 or 532 should set If you find one of these codes using the blink code function follow the DTC diagnostic chart recommendations in the DTC section of this manual 84 SM20042002LPGDBW USING A LAPTOP COMPUTER TO DIAGNOSE THE SPECTRUM SYSTEM A laptop computer is the preferred tool for performing diagnostic testing of the Spectrum system A laptop computer with the system diagnos
177. rature Observe the MIL Observe engine performance and SM20042002LPGDBW 111 DTC 121 ECT High Voltage YEL GRY Sensor Ground Conditions for Setting the DTC ECT Engine Coolant Temperature Check Condition Engine Running E sadi Fault Condition ECT sensor voltage exceeds 4 95 deg F MIL On during active fault and for 2 seconds after active fal Adaptive Disabled during active fault Closed Loop Enabled Circuit Description The ECT Engine Coolant Temperature sensor is a temperature sensitive resistor located in the engine coolant It is used for the engine airflow calculation gasoline cold enrichment and to enable other temperature dependant 2 689 features The ECM provides a voltage divider circuit 5 576 so that when the coolant is cool the signal reads higher voltage and lower when warm This fault will set if the signal voltage is greater than 4 95 volts anytime the engine is running The ECM will use a default value for the ECT sensor in the event of this fault 99 301 112 SM20042002LPGDBW DTC 121 ECT VOLTAGE HIGH Step Yes No Did you perform the On Board OBD System LT Go to OBD Check 2 System Check Section 2 Go to step Intermittent KeyOn 3 problem DST Diagnostic Scan Tool connected in Go to System Data Mode Intermittent Does DST display ECT voltage of 4 95 or section Key Off Go to step Go to Step 3 Disconnect the ECT sensor from the
178. rce Closed Loop Operation Applies to systems utilizing an oxygen sensor In this mode of operation the system uses oxygen sensor information to determine air fuel ratio Adjustments are made accordingly and checked by com paring the new oxygen sensor to previous signals No stored information is used CNG Compressed Natural Gas CKP Crankshaft Position Sensor CMP Camshaft Position Sensor Conductor A material normally metallic that permits easy passage of electricity Contaminants Impurities or foreign material present in fuel Control Module One of several names for a solid state microcomputer which monitors engine conditions and controls certain engine functions i e air fuel ratio injection and ignition time etc Converter A LPG fuel system component containing varying stages of fuel pressure regulation combined with a va porizer Cryogen A refrigerant used to obtain very low temperatures Current The directed flow of electrons through a conductor Measured in amps Dedicated Fuel System A motor fuel system designed to operate on only one fuel type Diaphragm A thin flexible membrane that separates two chambers When the pressure in one chamber is lower than in the other chamber the diaphragm will move toward the side with the low pressure Diaphragm Port The external port located at the fuel inlet assembly and connected to the vacuum chamber above the air valve diaphragm Digital Volt Ohm Meter DVOM A meter
179. re sensor A temperature sensitive resistor is used in the TMAP located in the intake manifold of the engine It is used to monitor incoming air temperature and the output in conjunction with other sensors is used to determine the airflow to the engine The ECM provides a voltage divider circuit so that when the air is cool the signal reads higher voltage and lower when warm The IAT is a calculated value based mainly on the IAT sensor at high airflow and influenced more by the ECT Engine Coolant Temperature at low airflow This fault will set if the signal voltage is more than 4 95 volts anytime the engine is running The ECM will use the default value for the IAT sensor in the event of this fault SM20042002LPGDBW er Ca 111 IAT VOLTAGE ots tion Did you perform the On Board OBD System Go to Step Go to OBD Check 2 System Check Section Intermittent Key On problem e DST Diagnostic Scan Tool connected in Go to System Data Mode Intermittent section Does DST display IAT voltage of 4 95 or greater Key OFF Jumper TMAP sensor connector signal pin B to engine ground Key ON Does DST display IAT voltage of 0 1 volts or less Is the replacement complete Key OFF Disconnect the ECM wire harness connector Check for continuity between TMAP sensor connector signal pin B and ECM IAT signal pin 32 Do you have continuity between them Go to Step 11 Go to step 1 Repair the circuit as
180. re the DTC 721 previously set Observe the MIL Observe engine performance and drive ability After operating the engine within the test parameters of DTC 721 check for any stored codes Does the engine operate normally without setting DTC 721 Replace the ECM Go to Step 8 Is the replacement complete Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature running the transmission to similar conditions where the DTC 721 previously set Observe the MIL Observe engine performance and drive ability After operating the engine within the test parameters of DTC 721 check for stored codes Does the engine operate normally with no stored codes Remove all test equipment except the System OK DST 250 SM20042002LPGDBW SM20042002LPGDBW SECTION 1E1 FUEL SYSTEM 251 REPAIR INSTRUCTIONS PROPANE FUEL SYSTEM PRESSURE RELIEF A WARNING The propane fuel system operates at pressures up to 21 5 BAR 312 psi To minimize the risk of fire and personal injury relieve the propane fuel system pressure where applicable before servicing the propane fuel system components To relieve propane fuel system pressure 1 Close the manual shut off valve MSV on the propane fuel tank 2 Start and run the vehicle until the engine stalls 3 Turn
181. revent dust dirt and debris from being introduced to the fuel cylinder and prolong the life of the fuel filter Inspection And Replacement Of The Fuel Filter The Propane system on this emission certified en gine utilizes an in line replaceable fuel filter element This element should be replaced at the intervals specified in the recommended maintenance sched ule When inspecting the fuel filter check the follow ing 13 Check for leaks at the inlet and outlet fittings us ing a soapy solution or an electronic leak detec tor if leaks are detected make repairs Check to make sure filter is securely mounted Check filter housing for external damage or dis tortion if damaged replace fuel filter To replace the filter use the following steps 1 Move the equipment to a well ventilated area and insure all external ignition sources are not present 2 Start the engine 3 With the engine running close the manual valve 4 When the engine runs out of fuel turn OFF the key when the engine stops and disconnect the battery negative cable A WARNING A small amount of fuel may still be present in the fuel line use gloves to prevent burns wear proper eye protection If liquid fuels continues to flow from the connections when loosened check to make sure the manual valve is fully closed Slowly loosen the inlet fitting and disconnect Slowly loosen the outlet fitting and disconnect Remove the filter housing
182. rew driver push locking clips back on FTV connection at FTV and LPR 2 Remove the hose and discard 259 Installation Procedure A CAUTION FTV hoses are specifically designed DO NOT use hose material or length other than the OEM specified parts 3 Reinstall hose at the FTV and LPR and push locks in place 4 Start engine and check for leaks ENGINE CONTROL MODULE REPLACEMENT Disconnect Negative battery cable 2 Remove controller from mounting bracket 3 Push connector lock back to unlock con nector 4 Unplug controller and remove Installation Procedure Controller is calibrated for each engine verify you have the correct controller 5 Plug connector into controller 6 Push lock into place 7 Mount controller into mounting bracket 8 Reconnect the battery cable 9 Install Diagnostic service tool 10 Start engine 11 Check for any DTC codes and clear 12 Verify engine is in closed loop and no MIL lights are present 260 HEATED EXHAUST GAS OXYGEN SENSOR REPLACEMENT 1 Disconnect the O 2 sensor electrical con nector 2 Using a O 2 Sensor socket remove the O 2 Sensor and discard Installation Procedure Before install the O 2 sensor lubricate threads with anti seize compound GM P N 5613695 or equivalent Avoid getting compound on the sensor tip 3 Install O 2 sensor Tighten 41 Nem 30 lb ft 4 Start engine 5 Check for any DTC codes and clear 6 Verify engine is
183. ring Repairs in Engine Electrical Go to Step 18 Go to Bod Bod Replace ECM Refer to ECM replacement in the Engine Controls Section Is the replacement complete e Check for continuity between TMAP Repair the Go p sensor connector pin D and engine circuit as ground necessary Do you have continuity Refer to Wiring Repairs in Engine Electrical Replace TMAP sensor 17 Is the replacement complete SM20042002LPGDBW 137 Remove all test equipment except the System OK Go to OBD DST System Connect any disconnected components Check fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 135 check for any stored codes Does the engine operate normally with no stored codes 138 SM20042002LPGDBW SM20042002LPGDBW 139 DTC 142 Crank Sync Noise GRY BRN Crank PPL ORN 12 Conditions for setting the DTC Crankshaft Position sensor Check Condition Engine running Fault Condition 1 invalid crank re sync MIL On during active fault and for 10 seconds after active fault Adaptive Disabled for the remainder of the key on cycle Closed Loop Enabled Circuit Description 140 The Crankshaft Position sensor is a magnetic transducer mounted on the engine block ad
184. s shown in this service manaual that have tool product numbers beginning with J or BT are available for world wide distribution from o Kent Moore Tools o 28635 Mound Road o Warren MI 48092 1 800 345 2233 Special Tools which are required to service the LPG fuel system are listed below SM20042002LPGDBW o Hand held diagnostic scanner ITK 1 Fuel pressure test kit The tools are available from IMPCO Engine System Division 7100 East 15 Mile Road Sterling Heights MI 48312 1 586 276 4333 English And Metric Fasteners A CAUTION Late model engines use a combination of English and Metric fasteners The components affected are the starter motor engine mounts and flywheel hous ing mounting Other components may also have a combination of fasteners always verify that the proper fasteners are used whenever removing or re placing any components Handling Electrostatic Discharge ESD Sensitive Parts Many solid state electrical components can be dam aged by electrostatic discharge ESD Some will display a label but many will not In order to avoid possibly damaging any compo nents observe the following 1 Body movement produces an electrostatic charge To discharge personal static electricity touch a ground point metal on the vehicle This should be done any time you e Slide across the vehicle seat Sit down or get up Do any walking 2 Do not touch exposed electric terminals on
185. s that must be carefully observed in order to reduce the risk of personal injury during service or repair Improper service or repair may damage the engine or render it unsafe or fail to make the engine emissions com pliant It is also important to warn of all hazardous consequences that might result from careless treat ment of the engine Failure to observe these items could influence terms of the warranty To reduce the chance of personal injury and or prop erty damage the following instructions must be care fully observed Proper service and repair are important to the safety of the service technician and the safe reliable opera tion of all engines The service procedures recom mended and described in this service manual are effective methods of performing service and repair Some of these procedures require the use of tools specially designed for the purpose If part replacement is necessary the replacement part must be of the same part number or equivalent part Do not use a replacement part of lesser qual ity In the case of replacement parts for the emission control system use only genuine OEM replacement parts Before using a replacement part service procedure or a tool which is not recommended by the engine manufacturer it must first be determined that neither personal safety nor the safe operation of the engine will be jeopardized by the replacement part service procedure or the tool selected Special service tool
186. seal to the bulkhead base SM20042002LPGDBW 10 11 Install the filter to the bulkhead base Install the filter housing to the bulkhead base Install sealing washer and retaining bolt and tighten to specification Tighten 27 Nm 20 ft Ibs Tighten the fuel inlet hose fitting to specifi cation Tighten 27 Nm 20 ft Ibs 12 Reconnect the negative battery cable 13 Open manual shut off valve 14 Start the vehicle and leak check the pro pane fuel system at each serviced fitting Refer to Propane Fuel System Leak Test Inlet fitting to Electric Lock off Coolant Inlet Fitting Coolant Flow Restrictor Electric Lockoff Er Adapter Lockoff to LPR Low Pressure Regulator LPR Pressure Trim Valve PTV Guard PTV Secondary Test Port Cap Primary Test Port e Em y fi X J 4 4 9 R SL 4 4 Vapor Oulet DA 5 Pi Fitting C Fitting Retaining Pins Coolant Outlet Fitting PTV Mounting Bolts LPR Mounting Bolts LPR Mounting Bracket Figure 2 Low Pressure Regulator LOW PRESSURE LOCK OFF LPL SM20042002LPGDBW 253 REPLACEMENT Figure 2 Removal Procedure 1 Relieve the propane fuel system pressure Refer to Propane Fuel System Pressure Relief 2 Disconnect the negative battery cable 3 Disconnect the LPL electrical connector 4 Disconnect the LPG fuel inlet line from the LPL inlet fitting 5 Unscre
187. sure that the manual shut off valve on the LPG tank is fully opened and that the excess flow valve has not been activated SM20042002LPGDBW Tools Required Test Description e 7 16 Open end wrench for test port plugs The numbers below refer to step numbers on the e Straight Blade screw driver diagnostic table e DVOM GM J 39200 Fluke 88 or equivalent Duty Cycle Monitoring Tool 5 This step will determine if the fuel control e Fuel System Analyzer FSA or DVOM solenoid FCS and fuel supply system are GM J 39200 Fluke 88 or equivalent functioning properly The vacuum on the Diagnostic Scan Tool secondary test port will be approximately 1 0 held PDA or equivalent to 2 0 w c If the vehicle has a hard start or Pressure Gauges poor idle check for proper operation of the idle e Water Column Gauge Manometer GM 7333 6 control solenoid ICS 6 This step checks the base mechanical LPR ge output pressure by disabling all fuel control devices 9 This step checks for proper air valve operation 19 This determines if fuel is available from the fuel tank supply system LPG Fuel System Diagnosis Value s Yes no Were you referred to this procedure by a Go to Step 3 Go to Step 2 DTC diagnostic chart Go to the applicable DTC Table Step 3 Perform the On Board Diagnostic OBD System Check Are any DTCs present in the ECM Connect a water column
188. t lines Check coolant supply hose clamp connections ensure they are tight Check the to ensure the Pressure Trim Valve PTV mounting bolts are secure Check PTV for external amage Check PTV electrical connection to ensure the connector is seated and locked e Check to ensure the regulator is securely mount ed Checking draining Oil Build up In The Low Pressure Regulator During the course of normal operation oil or heavy ends may build inside the secondary chamber of the Low Pressure Regulator LPR These oil and heavy ends may be a result of poor fuel quality contamina tion of the fuel supply chain or regional variation of the fuel make up If the build up of oil becomes significant this can affect the performance of the sec ondary diaphragm response The Recommended Maintenance Schedule found in this section recom mends that the oil be drained periodically SM20042002LPGDBW Draining the regulator when the engine is warm will help the oils to flow freely from the regulator To drain the LPR use the following steps 1 Move the equipment to a well ventilated area and ensure no external ignition sources are present 2 Start the engine 3 With the engine running close the manual valve 4 When the engine runs out of fuel turn OFF the key when the engine stops and disconnect the battery negative cable A WARNING A small amount of fuel may still be present in the fuel line use gloves to prevent
189. t when the MAP reading is higher than it should be for the given TPS and RPM When the fault is set the Adaptive Learn will be disabled for the remainder of the key on cycle and the MIL will be on The engine will operate on a default MAP during this active fault Diagnostic Aids If the engine is running rough unstable or missing due to a suspected mechanical problem vacuum leak or other issue causing misfire these problems must be taken care before using the MAP diagnostic chart Failure to follow this recommendation will result in a false MAP diagnostic and repair procedure SM20042002LPGDBW aa 131 MAP HIGH PRESSURE Action Value s Yes No Did you an the On Board OBD System Go to Step Go to OBD 2 System Check Section 3 5 Key On Engine running DST Diagnostic Scan Tool connected in System Data Mode Does DST display MAP pressure of 13 0 psia or greater with the engine idling Go to step Intermittent 3 problem Go to Intermittent section Go to step Go p 4 Go to step Go 5 Go to step Go to Step 6 10 7 Go to step Repair the 7 circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to step 11 SM20042002LPGDBW 125 Key OFF Disconnect the TMAP sensor connector e Key ON Does the DST display MAP pressure less than 0 05 psia e Probe TMAP sensor ground circuit pin A with a test light connected to battery voltage Does the test light come on
190. tamination Inspect HO2S connector terminals A B C and D for damage corrosion or contamination Did you find a problem Remove all test equipment except the DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 212 check for any stored codes Does the engine operate normally with no stored codes Go to Step Go to Step 6 Circuit as necessary Refer to Wiring Repairs in Engine Electrical System OK SM20042002LPGDBW Repair the circuit as necessary Refer to Wiring Repairs in Engine Electrical Repair the circuit as necessary Refer to Wiring Repairs in Engine Electrical Go to Step 9 Go to Step 7 Go to OBD System Check SM20042002LPGDBW 155 DTC 224 Closed Loop Multiplier Low LPG DK GRN ORN Sensor BLK LT GRN Sensor Ground PNK DK GRN To System Power Relay To Engine Ground Conditions for Setting the DTC Heated Oxygen Sensor Functional Fault Closed Loop multiplier out of range at limit of 35 MIL on during active fault Circuit Description The HO2S Heated Oxygen Sensor sensor is us
191. tem pressure Refer to Propane Fuel System Pressure Relief 2 Disconnect the negative battery cable 3 Clamp the coolant hoses to the LPR or drain the radiator 4 Remove the LPL Refer to Low Pressure Lock off Replacement 5 Remove the PTV Refer to Pressure Trim Valve Replacement 6 Disconnect the supply and return coolant lines from the LPR 7 Remove the retaining pin from the water inlet and outlet fittings and retain 8 Remove the coolant inlet and outlet fitting retaining pins and retain SM20042002LPGDBW 9 Remove the outlet fitting locate the orifice in the housing or attached to the fitting and retain 10 Remove the inlet fitting retain 11 Disconnect the FTV supply line 12 Remove the two LPR mounting bolts and retain 13 Lift LPR assembly and remove 14 Loosen the fuel vapor hose clamp at the LPR fuel outlet fitting 15 Disconnect the fuel vapor hose from the LPR outlet fitting and remove the LPR 16 Remove the retaining pin from the vapor outlet fitting and retain 17 Remove and retain the vapor outlet fitting from the LPR 18 Remove the LPR Installation Procedure A CAUTION Do not use Teflon tape on any fuel fitting Use a liquid pipe thread sealant when installing fit tings Lubricate the o ring of the PTV before installing into the LPR Lubricate the o rings on each of the fitting Be sure to reinstall regulator coolant line orifice into the outlet side of the L
192. that uses a numerical display in place of a gauge and is usually of the high impedance type 4 SM20042002LPGDBW DTC Diagnostic Trouble Code DST Diagnostic Scan Tool DVOM Digital volt ohmmeter ECT Engine Coolant Temperature ECM Electronic Control module EFI Electronic Fuel Injection A fuel injection system which uses a microcomputer to determine and control the amount of fuel required by and injected into a particular engine EGR Exhaust gas recirculation EPA Environmental Protection Agency A regulating agency of the Federal government which among other duties establishes and enforces automotive emissions standards Ethanol Grain alcohol C2H5OH generally produced by fermenting starch or sugar crops Evaporative Emissions Controls An automotive emission control system designed to reduce hydrocarbon emissions by trapping evaporated fuel vapors from the fuel system Excess Flow Valve A check valve that is caused to close by the fuel when the flow exceeds a predetermined rate Forced Idle ECM commands electronic throttle controller to an idle position FTV Fuel Trim Valve FFV Flexible Fuel Vehicle Firing Line The portion of an oscilloscope pattern that represents the total amount of voltage being expended through the secondary circuit FMVSS Federal Motor Vehicle Safety Standards FPP Foot Pedal Position Sensor Fuel Injector a spring loaded electromagnetic valve which delivers fuel into the intak
193. the tank and delivered under pressure to the system as a liquid During key on the LPL receives a two 2 second prime pulse from the ECM which allows LPG to flow from the tank through fuel filter and fuel lines to the low pressure regulator LPR at pressures up to 312 psi In the LPR the fuel is vaporized and the pres sure reduced in two stages The first stage reduces the pressure to approximately 4 5 psi The second stage reduces the pressure to ap proximately negative 1 5 of water column 34 Low Pressure Regulator LPR Coolant Flow 2 Restrictor Pressure Trim pa Valve PTV Guard PTV Coolant Outlet Fitting N x Vapor Fuel Outlet Fitting PAR PTY Mounting Bolts The fuel is then drawn from the secondary chamber of the LPR by the vacuum generated by air flowing through the mixer This vacuum signal is also used to generate lift for the mixer air valve This vacuum signal is most commonly referred to as air valve vacuum In the mixer the fuel mixes with the air entering the engine This air fuel mixture is then drawn into the engine for combustion Diagnostic Aids This procedure is intended to diagnose a ve hicle operating on LPG If the vehicle will not continue to run on LPG refer to Hard Start for preliminary checks Before proceeding with this procedure verify that the vehicle has a suf ficient quantity of fuel and that liquid fuel is be ing delivered to the LPR Also en
194. them e Replace ECM Is the replacement complete Remove all test equipment except the System OK Go to OBD DST Connect any disconnected components fuses etc Using the DST clear DTC information from the ECM Turn the ignition OFF and wait 30 seconds Start the engine and operate the vehicle to full operating temperature Observe the MIL Observe engine performance and driveability After operating the engine within the test parameters of DTC 637 check for any stored codes Does the engine operate normally with no stored codes 234 SM20042002LPGDBW SM20042002LPGDBW 235 DTC 638 Throttle Unable To Close TPS 1 Signal Sensor Ground TPS 2 Signal 5 VOLTS Conditions for Setting the DTC Throttle Position Sensor Check Condition Cranking or Running Fault Condition Throttle position is 2096 greater than throttle command MIL On during active fault Engine Shut Down Circuit Description 236 There are 2 Throttle Position Sensors located within the throttle which use variable resistors to determine signal voltage based on throttle plate position TPS1 will read low voltage when closed and TPS2 will read high voltage when closed The TPS1 and TPS2 percentages are calculated from these voltages Although the voltages are different the calculated values for the throttle position percentages should be very close to the same The TPS values are used by the ECM to determine if the throttle is opening
195. tic cable and diagnostic software is used to read and clear Diagnostic Trouble codes It is also used to monitor sensor and actuator values The diagnostic software also performs several special tests The following procedures will assist you in using a laptop computer to diagnose the Spectrum system INSTALLING THE SPECTRUM DIAGNOSTIC SOFTWARE Loading Software and Connecting the Computer Start Windows e Insert the Diagnostic Interface software CD e Click on the START button e From the Start menu select RUN In the command line text box type the letter of your CD ROM drive followed by setup for example e setup then click OK e Follow the on screen instructions Connecting a Laptop Computer to the Spectrum System Connect the system diagnostic cable to the RS232 port on the back of the computer If you do not have a RS232 port use the USB to RS232 adapter supplied in the IMPCO ITK 2 test kit e Connect the diagnostic cable to the diagnostic connector on the engine harness The diagnostic connector is a square 4 pin connector located near the Spectrum system ECM e Turn the computer ON Start Windows e From the Start menu select Programs Select IMPCO Display e Place the ignition key in the ON position The system Gauge screen should now appear and a green banner in the upper left hand will read Connected SM20042002LPGDBW 85 DIAGNOSTIC TROUBLE CODES EDIS ECI Serial Communications
196. ting adjustment to the fuel deliv ery based on feedback from the HEGO The closed loop multiplier is expressed as a percent age 96 and is not stored in the ECM s memory Fuel and timing modified based on feedback from the O2 sensor Drive by wire Diagnostic Trouble Code A code which is stored in the ECM when an ECM initiated test fails Engine Coolant Temperature Engine Control Module The computer which controls the fuel and ignition system on the en gine See HO2S ECM commands electronic throttle controller to an idle position Foot Pedal Position Heated Oxygen Sensor Intake Air Temperature Idle Validation Switch Secondary engine speed control only used to limit speed when throttle positioning is not main taining desired speed Manifold Absolute Pressure The pressure of the air in the intake manifold Manifold Air Temperature The temperature of the air in the intake manifold Malfunction Indicator Light A dash mounted light that illuminates when the ECM senses a system fault Milli seconds 1 1000 of a second Fuel and timing based strictly on tables stored in the ECM ECM has detected condition in throttle control and limits throttle blade opening to 50 ECM has detected condition in throttle control and limits throttle blade opening to 2096 Pounds per square inch absolute 14 7 psia 0 psig Random Access Memory The portion of computer memory within the ECM which changes as the engine is running and is stor
197. tor C001 Go to Step Repair the Check continuity between FPP sensor 6 circuit as Key OFF Disconnect FPP sensor connector Inspect connector and wire terminals for damage corrosion or contamination Any problems found connector ground pin B and ECM necessary connector FPP sensor ground pin 49 Refer to Do have continuity between them Wiring Repairs in Engine Electrical Repair the Go to Step circuit as 7 necessary Refer to Wiring Repairs in Engine Electrical Key ON Using a DVOM check for voltage at ECM wire harness connector FPP signal pin 38 and ECM sensor ground terminal pin 49 Do you have voltage between them SM20042002LPGDBW 197 Step _____Aetion_____ _Valve s Using a DVOM check for voltage at ECM Repair the Intermittent wire harness connector between ECM circuit as problem FPP signal pin 38 and engine ground necessary Goto Do you have voltage between them Refer to Intermittent Wiring section Repairs in Engine Electrical Key OFF Go to Step Go to Step Disconnect FPP sensor from wire 11 9 harness Key ON Does DSC display FPP voltage less than 0 2 volts e Disconnect ECM wire harness connector Repair the Go to Step C001 circuit as 10 Using a DVOM check for voltage necessary between the ECM FPP signal pin 38 and Refer to engine ground Wiring Repairs in Engine Electrical Is the replacement complete 15 11 Probe FPP sensor connector ground Go to Ste
198. tor for 5 volts between pins C LT GRN RED and pin D BLK with the ignition key in the on position You may still be able to retrieve a code using the blink code function if none of the above recommendations prove useful In the event of a 5 volt reference signal malfunction DTC 531 or 532 should set If you find one of these codes using the blink code function follow the DTC diagnostic chart recommendations in the DTC section of this manual SM20042002LPGDBW 91 OBD System Check Malfunction Indicator Lamp C022 LT BLUE BLK 3 Hot in Start and Run Circuit Description The Spectrum Fuel system is equipped with OBD On Board Diagnostics The system has a dash mounted MIL Malfunction Indicator Lamp for the indication of system problems Engine control system problems that affect emissions or driveability of the vehicle will set a DTC Diagnostic Trouble Code The ECM will then provide a path to ground and illuminate the MIL Malfunction Indicator Lamp The MIL has the following functions 1 It notifies the driver of a problem with the fuel system ignition system or emission control system so the driver can arrange for service as soon as possible 2 It will display DTC s that have been stored due to a system malfunction The lamp should illuminate when the key is in the ON position and the engine is not running This feature verifies that the lamp is in proper working order If the lamp does not c
199. ttle body Check the fuel system pressures Refer to the Fuel System Diagnosis 48 SM20042002LPGDBW Ignition System Checks Engine Mechanical Checks SM20042002LPGDBW Note LPG being a gaseous fuel requires higher secondary ignition system voltages for the equivalent gasoline operating conditions Check for the proper ignition voltage output with J 26792 or the equivalent Verify that the spark plugs are correct for use with LPG R46TS Check the spark plugs for the following conditions Wet plugs Cracks Wear Improper gap Burned electrodes Heavy deposits Check for bare or shorted ignition wires Check for moisture in the distributor cap if applicable Check for loose ignition coil connections Important 1 If the engine starts but then immediately stalls Crankshaft Position CKP 2 Check for improper gap debris or faulty connections Important The LPF Fuel system works on a fumigation principle of fuel introduction and is more sensitive to intake manifold leakage than the gasoline fuel supply system e Check for the following Vacuum leaks Improper valve timing Low compression Bent pushrods Worn rocker arms Broken or weak valve springs Worn camshaft lobes Ref Check the intake and exhaust manifolds for casting flash 49 Exhaust System Checks Check the exhaust system for a possible restriction Inspect the exhaust system for damaged or collapsed pipes Inspect the muffler for signs of he
200. ty Recommendation 5 Use Of Supplemental Additives Use of the oils recommended by the engine manu facturer already contains a balanced additive treat ment The uses of supplemental additives which are added to the engine oil by the customer are not necessary and may be harmful The engine manufacturer fuels system suppliers and engine distributors do not review ap prove or recommend such products Synthetic Oils Synthetic oils have been available for use in in dustrial engines for a relatively long period of time 6 Synthetic oils may offer advantages in cold tempera ture pumpability and high temperature oxidations resistance However synthetic oils have not proven 7 to provide operational or economic benefits over conventional petroleum based oils in industrial en gines Their use does not permit the extension of oil 8 change intervals 12 GRADE MAY BE USED AT level Stop engine if in use Allow sufficient time approximately 5 minutes for the oil to drain back into the oil pan Remove the dipstick Wipe with a clean cloth or paper towel and reinstall Push the dipstick all the way into the dipstick tube Remove the dipstick and note the oil level Oil level must be between the FULL and ADD marks DIPSTICK FULL MARK R ADD MARK Figure 2 Engine Oil Dip stick Typical If the oil level is below the ADD mark proceed to Step 7 and 8 and reinstall the dipstick
201. ult and for 2 seconds after active fault Adaptive Disabled during active fault Closed Loop Enabled Circuit Description The ECT Engine Coolant Temperature sensor is a temperature sensitive resistor located in the engine coolant It is used for the engine airflow calculation gasoline cold enrichment and to enable other temperature dependant features The ECM provides a voltage divider circuit so that when the coolant is cool the signal reads higher voltage and lower when warm This fault will set if the signal voltage is less than 0 05 volts anytime the engine is running The ECM will use a default value for the ECT sensor in the event of this fault 116 SM20042002LPGDBW DTC 122 ECT VOLTAGE LOW Step Yes No Did you perform the On Board OBD System Go to OBD Check 2 System Check Section Go to step Intermittent Key On 3 problem e DST Diagnostic Scan Tool connected in Go to System Data Mode Intermittent Does DST display ECT voltage of 0 05 or SeCUoH less Key Off Go to step Go to step Disconnect the ECT wire harness 4 5 connector Key ON Does the DST display ECT voltage of 4 9 volts or greater 4 Replace ECT sensor Go to Step Is the replacement complete 8 Key OFF Repair the Go to step 5 Disconnect ECM wire harness connector circuit as 6 Check for continuity between ECT sensor necessary Refer to Wiring Repairs in Engine Electrical e Check for continu
202. und in many crude oils Backfire Combustion of the air fuel mixture in the intake or exhaust manifolds A backfire can occur if the intake or ex haust valves are open when there is a mis timed ignition spark Benzene An aromatic C6H6 Sometimes blended with gasoline to improve antiknock value Benzene is toxic and suspected of causing cancer Bi Fueled A vehicle equipped to run on two fuels at the same time such as a fumigated diesel Blow By Gases formed by the combustion of fuel and air which ordinarily should exert pressure only against the pis ton crown and first compression ring When rings do not seal these gases blowby escape down the side of the piston into the crankcase BTU British Thermal Unit A measurement of the amount of heat required to raise the temperature of 1lb of water 1 degree F Butane An odorless colorless gas C4H10 found in natural gas and petroleum One of the five LP gases CAFE Corporate Average Fuel Economy CARB California Air Resources Board Carbon Monoxide CO A chemical compound of a highly toxic gas that is both odorless and colorless Carburetor An apparatus for supplying an internal combustion engine a mixture of vaporized fuel and air Cathode Ray Tube A vacuum tube in which cathode rays usually in the form of a slender beam are projected on a fluorescent screen and produce a luminous spot Circuit A path of conductors through which electricity flows before it returns to its sou
203. uring this fault SM20042002LPGDBW DTC 636 TPS 1 Lower Than TPS 2 Value s Yes No Did you 191 the On Board System ALS Go to OBD 2 System Check Section Key ON Engine OFF Goto Step Intermittent e DST Diagnostic Scan Tool connected in 3 problem System Data Mode Go to Does the DST display more than a 2096 Intermittent difference between TPS 1 and TPS 2 section Key OFF Go to Step Go to Step Disconnect wiring harness connector to S 4 throttle Key ON Change DST mode to DBW drive by wire test mode Is the voltage for TPS 1 and TPS 2less than 0 1 volts Key OFF Repair Go to Step Disconnect ECM wiring harness the TPS 1 13 connector or TPS 2 Key ON circuit as necessary Refer to Wiring Repairs in Engine Electrical Jumper TPS 1 and TPS 2 signal to the 5 Go to Step Go to Step volt reference at the throttle connector 6 8 Does DST display TPS 1 and TPS 2 voltage over 4 95 volts e Inspect wire terminals at throttle Repair the Go je os connector for damage corrosion or circuit as contamination necessary Any problems found Refer to Wiring Repairs in Engine Electrical Replace Throttle Go v D Is the replacement complete SM20042002LPGDBW 229 Using a DVOM check for voltage between TPS 1 or TPS 2 the one that is over 0 1 volts and engine ground Do you have voltage Key OFF Disconnect ECM wire harness connector from ECM Using a DVOM check for
204. vel 1 has detected condition in throttle control and limits throttle blade opening to 50 Power Derate Level 2 has detected condition in throttle control and limits throttle blade opening to 20 Pressure Differential The differential between atmospheric pressure and intake manifold referred to as vacuum pres sure Pressure Regulator A device to control the pressure of fuel delivered to the fuel injector s Primary Circuit The low voltage or input side of the ignition coil Propane An odorless colorless gas C3H8 found in natural gas and petroleum PTV Pressure Trim Valve Reactivity Refers to the tendency of an HC in the presence of Nox and sunlight to cause a smog forming reaction The lighter the HC the lower reactivity tends to be Regulator An assembly used to reduce and control the pressure of a liquid or vapor Resistance The opposition to the flow of current in an electrical circuit Measured in ohms SM20042002LPGDBW 7 SM20042002LPGDBW SECTION 0B MAINTAINENCE SM20042002LPGDBW Maintenance The maintenance of the engine and its related components is critical to the life of the engine and optimum performance during its useful life All en gines require a certain amount of maintenance The suggested maintenance requirements are contained in this section Industrial engines operate in various environments from extremely dusty environments to hot and cold temperature environments and clean envir
205. w the LPL from the LPR inlet fitting Installation Procedure Do not use Teflon tape on any fuel fitting Use a liquid pipe thread sealant when installing fit tings 6 Apply pipe thread sealant to the LPR inlet fitting 7 Install the LPL to the LPR Tighten the LPL finger tight plus 1 to 2 turns and place the LPL in the correct position Install the fuel inlet line Tighten the fuel line fitting to the LPL Tighten 27 Nm 20 ft Ibs 10 Connect the LPL electrical connector 11 Connect the negative battery cable 12 Slowly open the tank manual shut off valve 13 Start the vehicle and leak check the pro pane fuel system at each serviced fitting PRESSURE TRIM VALVE PTV REPLACEMENT Figure 2 1 Disconnect the PTV electrical connection 2 Remove the vacuum hose from the PTV 254 3 Remove and retain the two 2 retaining bolts and PTV guard 4 Remove the PTV Installation Procedure Apply a small amount of O ring lubricant to the PTV O ring before installation 5 Install the PTV and guard using the two mounting bolts 6 Tighten retaining bolts Tighten 9 Nem 80 Ib in Connect the PTV vacuum line 8 Connect the PTV electrical connector 9 Start the vehicle 10 Connect the diagnostic service tool and verify the engine is operating in closed loop and no MIL light is present LOW PRESSURE REGULATOR LPR REPLACEMENT Figure 2 Removal Procedure 1 Relieve the propane fuel sys
206. xerted on the pri mary diaphragm to cause the diaphragm plate to pivot and press against the primary valve pin thus closing off the flow of fuel This action causes the flow of fuel into the regulator to be regulated When the engine is cranking suf ficient vacuum will be introduce into the second ary chamber from the mixer drawing the sec ondary diaphragm down onto the spring loaded lever and opening the secondary valve allowing vaporized fuel to pass to the mixer Increased vacuum in the secondary chamber increases the downward action on the secondary lever causing it to open wider allowing more fuel to flow to the mixer The regulator utilized on this emission certified engine is equipped with a unique Pressure Trim Valve PTV which is directly mounted to the regulator This solenoid is a 12 volt normally closed solenoid The function of this solenoid is to regulate a specific amount of venture vacuum to the atmospheric side of the secondary dia phragm By introducing vacuum to the top side of the secondary diaphragm during regulator operation the amount of fuel being delivered to the mixer can be trimmed or reduced to allow for correction to the air fuel ratio for closed loop fuel control The solenoid receives a reference signal from the ECM which causes the sole noid to be pulsed fast or slow depending on the amount of fuel to be trimmed SM20042002LPGDBW Coolant Inlet Fitting Coolant Flow Restrictor 1 4 6

DTC 244-Adaptive Learn Low (LPG)

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