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Troubleshooting

1. Troubleshooting Troubleshooting Procedures l How To Begin Troubleshooting When the Malfunction Indicator Lamp MIL has been reported on or there is a driveability problem use the appropri ate procedure below to diagnose and repair the problem A When the MIL has come on 1 Connect the Honda PGM Tester or an OBD Il scan tool to the 16P Data Link Connector DLC located under the glove box behind a removable cover 2 Turn the ignition switch ON II 3 Check the DTC and note it Also check and note the freeze frame data Refer to the Diagnostic Trouble Code Chart and begin troubleshooting MALFUNCTION INDICATOR NOTE See the OBD Il scan tool or Honda PGM Tester user s manuals for specific operating instructions e The scan tool or tester can read the Diagnostic Trouble Codes DTC freeze frame data current data and other Engine Control Module ECM data e Freeze frame data indicates the engine conditions when the first malfunction misfire or fuel trim malfunction was detected It can be useful information when troubleshooting B When the MIL has not come on but there is a driveability problem refer to the Symptom Chart on page 11 42 C DTCs will be indicated by the blinking of the Malfunction Indicator Lamp MIL with the SCS service connector con nected Connect the SCS service connector to Service Check Connector as shown The 2P Service Check Connector is located under the dash on th
2. e passenger s side of the vehicle Turn the ignition switch on Il SERVICE CHECK DATA LINK CONNECTOR 16P CONNECTOR 2P S My T Y KW OBD II SCAN TOOL or SCS SERVICE CONNECTOR HONDA PGM TESTER 07PAZ 0010100 11 38 ll Engine Control Module ECM Reset Procedure Either of the following actions will reset the ECM Using the OBD Il scan tool or Honda PGM Tester to clear the ECM s memory NOTE See the OBD II scan tool or Honda PGM Tester user s manuals for specific operating instructions Turn the ignition switch OFF Remove the CLOCK 7 5 A fuse from the under hood fuse relay box for 10 seconds CLOCK 7 5 A FUSE UNDER HOOD FUSE RELAY BOX ll Final Procedure this procedure must be done after any troubleshooting 1 Remove the SCS Service Connector if it is connected If the SCS service connector is connected and there are no DTCs stored in the ECM the MIL will stay on when the ignition switch is turned on 2 Do the ECM Reset Procedure 3 Turn the ignition switch OFF 4 Disconnect the OBD II scan tool or Honda PGM Tester from the Data Link Connector 16P IV Known Good ECM Substitution The ECM is part of the immobilizer system If you substitute a known good ECM the ECM will have a different immo bilizer code In order for the engine to start you must rewrite the immobilizer code with the Honda PGM Tester 11 39 Troubleshooting Troubleshooting Procedures con
3. icates changes occuring in the fuel supply system over a long period If long term fuel trim is higher than 1 00 the amount of injected fuel must be increased If it is lower than 1 00 the amount of injected fuel must be reduced The IAT sensor converts intake air temperature into voltage and signals the ECM When intake air tempera ture is low the internal resistance of the sensor increases and the voltage signal is higher Based on the accelerator pedal position the opening angle of the throttle valve is indicated Ignition Timing Calculated Load Value CLV 30 43 19 25 With cold engine Same as ambient temper ature and ECT At idle Approx 10 At full throttle Approx 90 The ignition advance angle is set by the ECM The ECM matches ignition timing to the driving conditions CLV is the engine load calculated from the MAP data At idle speed 15 2 BTDC with the SCS service connector connected At idle speed 15 35 At 2 500 rpm with no load 12 30 11 45
4. o output Engine Speed Vehicle Speed Manifold Absolute Pressure MAP The ECM computes engine speed from the signals sent from the Crankshaft Position sensor This data is used for determining the time and amount of fuel injection The ECM converts pulse signals from the Vehicle Speed Sensor VSS into speed data The absolute pressure created in the intake manifold by engine load and speed Nearly the same as tachometer indication at idle speed A T 780 50 rpm M T 800 50 rom Nearly the same as speedometer indication With engine stopped Nearly the same as atmo spheric pressure at idle speed 24 37kPa 180 280 mmHg 7 1 11 0 inHg Engine Coolant Temperature ECT Heated Oxygen Sensor HO2S Bank 1 Sensor 1 Bank 1 Sensor 2 Bank 2 Sensor 1 Bank 2 Sensor 2 11 44 The ECT sensor converts coolant temperature into volt age and signals the ECM The sensor is a thermistor whose internal resistance changes with coolant tem perature The ECM uses the voltage signals from the ECT sensor to determine the amount of injected fuel The Heated Oxygen Sensor detects the oxygen content in the exhaust gas and sends voltage signals to the ECM Based on these signals the ECM controls the air fuel ratio When the oxygen content is high that is when the ratio is leaner than the stoichiometric ratio the voltage signal is lower When the oxygen content is low that is when the ratio i
5. o page 11 38 Troubleshoot each probable cause in the order listed from left to right until the symptom is eliminated The probable cause and troubleshooting page reference can be found on next page SYMPTOM PROBABLE CAUSE Engine will not start 4 2 3 5 19 13 1 Hard starting 2 4 10 12 18 Cold fast idle too low 7 6 Cold fast idle too high Idle speed fluctuates Misfire or rough running Troubleshoot for misfire on pages 11 90 11 94 Low power 2 8 9 11 16 15 17 10 Engine stalls 2 4 10 19 7 5 14 Other Probable Causes Engine will not start Compression Engine locked up Timing belt Starting system Overheating Battery 11 42 K i Probable Cause List For the DTC chart see page 11 52 Probable Cause Page 1 11 61 11 62 Engine Control Module ECM 11 132 11 139 Fuel pressure and fuel pump relay 11 143 PGM FI main relay Section 23 Ignition system See DTC chart Crankshaft Position Cylinder Position sensor circuit See DTC chart Intake Air Temperature IAT sensor circuit 11 128 Idle speed adjustment 11 151 Throttle body 11 150 Throttle cable See DTC chart Manifold Absolute Pressure MAP sensor See DTC chart Throttle Position TP sensor O JOINIoO aA AJOJN Oo 4 12 See DTC chart Barometric press
6. s richer than the stoichio metric ratio the voltage signal is higher With cold engine Same as ambient temper ature and IAT With engine warmed up approx 176 194 F 80 90 C 0 0 1 25V At idle speed about 0 1 0 9V Data HO2S Feedback Loop Status Bank 1 Rear Bank 2 Front Description Operating Value Freeze Data Loop status is indicated as open or closed Closed Based on the H02S output the ECM deter mines the air fuel ratio and controls the amount of injected fuel Open Ignoring HO2S output the ECM refers to signals from the TP MAP and ECT sensors to control the amount of injected fuel Short Term Fuel Trim Bank 1 Rear Bank 2 Front Long Term Fuel Trim Bank 1 Rear Bank 2 Front Intake Air Temperature IAT Throttle Position At idle speed closed The air fuel ratio correction coefficient for correcting the amount of injected fuel wnen HO2S feedback is in the closed loop status When the signal from the HO2S is weak short term fuel trim gets higher and the ECM increases the amount of injected fuel The air fuel ratio gradually gets richer causing a higher HO2S output Consequently the short term fuel trim is lowered and the ECM reduces the amount of injected fuel This cycle keeps the air fuel ratio close to the stoichiometric ratio when in closed loop status Long term fuel trim in computed from short term fuel trim and ind
7. t d If the inspection for a particular code requires voltage or resistance checks at the ECM connectors remove the bulkhead panels Unbolt the ECM Check the system according to the procedure described for the appropriate code s listed on the following pages ECM BULKHEAD PANELS How to Use the Backprobe Sets Connect the backprobe adapters to the stacking patch cords and connect the cords to a multimeter Using the wire insula tion as a guide for the contoured tip of the backprobe adapter gently slide the tip into the connector from the wire side until it comes in contact with terminal end of the wire DIGITAL MULTIMETER Commercially available or KS AHM 32 003 STACKING PATCH CORD BACKPROBE SET 07SAZ 001000A two required BACKPROBE ADAPTER 11 40 CAUTION Puncturing the insulation on a wire can cause poor or intermittent electrical connections Bring the tester probe into contact with the terminal from the connector side of wire harness connectors in the engine compartment For female connectors just touch lightly with the tester probe and do not insert the probe RUBBER SEAL TESTER PROBE ULLAL Rg Bem WIRE HARNESS TERMINAL 11 41 Troubleshooting Troubleshooting Procedures cont d Symptom Chart Listed below are symptoms and probable causes for problems that DO NOT cause the Malfunction Indicator Lamp MIL to come on If the MIL was reported on go t
8. ure BARO sensor 13 11 122 11 125 A T gear position signal or clutch switch signal 14 11 127 Brake switch signal 11 149 Air Cleaner 16 11 154 Intake Air Bypass IAB control system and intake air pipe 11 159 Three Way Catalytic Converter TWC 11 167 Evaporative emission EVAP control Contaminated fuel 11 43 Troubleshooting Troubleshooting Procedures cont d ECM Data By connecting the OBD Il scan tool or the Honda PGM Tester to the 16P data link connector DLC various data can be retrieved from the ECM The items listed in the table below conform to the SAE recommended practice The Honda PGM Tester also reads data beyond that recommended by SAE Understanding this data will help to find the causes of intermittent failures or engine problems NOTE The operating values given below are approximate values and may be different depending on the environment and the individual vehicle e Unless noted otherwise at idle speed means idling with the engine completely warmed up A T in P or N position M T in neutral and the A C and all accessories turned off Description Operating Value Freeze Data Diagnostic Trouble Code DTC If the ECM detects a problem it will store it as a code consisting of one letter and four numbers Depending on the problem an SAE defined code POxxx or a Honda defined code P1xxx will be output to the tester If no problem is detected there is n

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