Engine Electronic Control System Service Manual
Contents
1. Speed sensor O A C evaporator sensor O O Air conditioner switches O O Fuel Enriching enrich ground wire O No1 Fuel Enriching enrich ground wire O No2 Ground wire ignition timing O Ignition switch O O O O O O O The function and general requirement are described as follows 1 Throttle position sensor Characteristics curve Wy U of Voltratio 4 e L Angle range Function it supplies information about the engine load and operating condition Principle In fact this sensor is a swivel arm potentiometer with linear output characteristics The swivel arm is coaxially mounted with the throttle When the throttle turning the swivel arm goes along with the throttle to indicate a certain resistance therefore the voltage signal output of the potentiometer is proportional to the position of throttle U Output signal voltage Uy Operating voltage N Theoretical characteristics curve T Characteristics curve deviation Engine Electronic Control System Service Manual page 12 of 65 Technical specifications Electronic angle range lt 96 Rotation direction Arbitrary Resistance 2K Q 20 Operating voltage 5V Operating temperature 30 C 110 C 40 C 120 C in short term Protection resistance for swivel arm 710 Q 1380 Q Permitted current for swivel arm lt I8SLA Service life 2 000 000 cycles2. ceeeeee eee es 52 4 6 Air conditioner control system e ccc eee eee seee 52 4 7 Primary faults checking flow cccceeeee eee eee 53 4 7 1 Difficult to start or not to start ccc cece cece eee 53 AD Poor IMIS speeds nirritorna a teen ena 54 4 7 3 Insufficient sPOW EL osss sien oi aa AAE A A 55 4 7 4 Engine responded sluggishly cecee eee 56 Br fe Ten S Unsteady vehicle E a E E EE E ee Oo 4 7 6 Over consumption of fuel cc cece eee e eee eeee 58 4 7 7 Emissions exceed Limits 9 500ssawestavcos Siena ss anaes 59 4 7 8 Self adaptation value out of limit 60 Engine Electronic Control System Service Manual page 4 of 65 4 8 Circuit diagram of engine electronic control system engine F SOPICS x E tps E and ree aed haa one ET 61 1 Precaution It is important to observe the follows during use check diagnosis and maintenance of the engine F series 1 When checking the electric elements without need of power disconnect the cathode of battery 2 When disconnecting the electrodes of battery disconnect the cathode first then the anode when connecting the battery do it in reverse order 3 Whenever using seal parts new gasket and O ring should be chosen as far as possible and the surface should be cleaned up to keep the tightness 4 After repairing any line check all related pipes and joints
3. General requirement The output signal value should be in conformity with the aperture width of the throttle prevent the sensor from showering impacting and shocking keep the connector in good appearance without dirt deformation and corrosion 2 Intake pressure temperature sensor Function It is used to gauge the absolute pressure in the intake manifold and supply the information on engine load Principle This sensor is composed of a Si chip The pressure diaphragm is etched on the chip the fixed value and rectifying circuits are also integrated on the chip Variation of air pressure will deform the diaphragm by force and its resistance changes on the effect of piezoresistance After processing by the chip the voltage signal is generated in linear relation with the pressure This sensor is direct mounted on the manifold To the sensor model DS S TF the air pressure and temperature sensors are integrated in one Features It adopts the advanced sensing technique and has _ the advantages of light body compact structure and small occupation in the manifold Eas feii ee Output voltage i55kPa Absolute pressure Characteristics curve Engine Electronic Control System Service Manual page 13 of 65 Section of pressure sensor model DS S Technical specification 1 Seal ring 2 Stainless steel bush 3 PCB base 4 Sensing element 5 Case 6 Pressure bracket 7 Welded connect
4. System Service Manual page 57 of 65 4 The engine operates in dull response The causes may be 1 The throttle position sensor or intake pressure and temperature sensor is out of work 2 There are something wrong with distributor ignition coil high tension wire and spark plug 3 The fuel delivery system has fault 4 The idle stepping motor does not operate properly 5 Ignition timing adjustment is improper 6 Mechanical faults such as insufficient pressure in the cylinder Repairing procedure 1 Eliminate all faults determined by the fault diagnosis instrument 2 Check the ignition advance angle at idle speed 3 Check and eliminate the ignition system fault 4 Check and eliminate the fuel delivery fault 5 Check and eliminate the other mechanical faults Engine Electronic Control System Service Manual page 58 of 65 5 The engine operates unsteadily The causes may be 1 There is something wrong with distributor ignition coil high tension wire or spark plug 2 The throttle position sensor or coolant temperature sensor is out of work 3 The fuel pressure is not steady 4 The spray nozzle has fault 5 The idle stepping motor does not operate properly 6 The voltage is too low e g the generator is damaged 7 There is a fault on ECU 8 Mechanical faults such as insufficient pressure in the cylinder Repairing procedure 1 Eliminate all faults determined by the fault diagnosis in
5. faults stated above have been found during diagnosis eliminate the faults according to the requirement for circuit repair the circuit must be in good contact and isolation to the other circuit nearby after repair then handle this circuit with moistureproof treatment 3 4 Power of Electronic Control engine management System and ignition switch circuit Circuit diagram To main relay l Ignition switch E i Battery anode IUNDE E Ground of power loop Ground of control loop Fault diagnosis Repeat turning on and off ignition switch Engine Electronic Control System Service Manual page 27 of 65 YES Check if energized click of relays is Power supply is normal heard Voltage of battery is less than 11V Charge the battery or replace it Measure if the resistance between the Make all ground ground terminals to cathode of battery is terminals in good contact less the 0 5 Q Measure if the voltage from pin No 18 to NO Check if the NO Replace the fuse ground is equal to that of battery fuse 7 5A is normal YES Measure if the voltage from pin No 27 to Check the wire from pin battery is equal to that of power supply No18 to anode of battery Check the harness from pin No27 to anode of battery and ignition switch Check the harness from pin No46 to NORMAL Replace ECU or main relay main relay and check the main relay Circuit diagram
6. stsouseiq Josuas JJeH JOSU S y Catalytic converter uomsoda yoy L Ioue ITV ISTUV poo uong Josu s TO nn a ne Joyooluy Joma Iosu s dura Ajea Bind amssard pny ssoid oyeyuy Joystues Sketch of Electronic control engine MPI engine 2 1 Air intake system idle stepping motor and It is composed of air cleaner throttle body manifold etc Function expression Function description Fresh air is filtered by air cleaner then it is distributed into the Engine Electronic Control System Service Manual page 8 of 65 combusting chamber through the manifold at a certain air flow rate controlled by throttle body When the engine running at idle speed the idle stepping motor actuates according to the command from ECU to control the air intake rate The intake manifold will generate vacuum pressure to supply the whole vehicle as a negative pressure source General requirement The air cleaner must have the function to filter the impurity dust from the atmosphere and have the intake resistance as small as possible The throttle can operate smoothly and its internal face surface keeps clear The air valve operated by the idle stepping motor must be clear without any obstruction There is not any crack air and water leakage on the manifold PVC valve Harness Manifold Timing i a check pointer hole Wna nns Throttle body Idle stepping motor To air cleaner Sketch of El
7. the coolant temperature above 70 C Trial run must be taken for 10s in the condition of throttle aperture width above 75 The engine must keep running at idle speed for 30s before it flameouts 3 2 Read out status parameter of the engine By means of the fault diagnosis instrument for electronic injection system recommended by Chang an Co the status parameters of the engine can be read out during the engine running e g speed coolant temperature etc these parameters is in aid of the service men to determine where the fault takes place and repair the vehicle The operation of the instrument refers to the instruction manual Notice Do not turn on the ignition switch before the diagnosis instrument connects with the Electronic Control engine management System If the diagnosis instrument has no response for a long time press the reset Engine Electronic Control System Service Manual page 26 of 65 key 3 3 Diagnosis on connectors and harness The fault of connectors and harness may have 4 sorts as follows 1 Broken circuit The poor contact or broken wire has happened in this circuit 2 Short circuit to the anode A part of the circuit connects to the anode where it is not allowed to do so 3 Short circuit to the cathode A part of the circuit connects to the cathode where it is not allowed to do so 4 Short circuit to each other the independent circuit connects to another one or electric leakage takes place If the
8. the sensor so as to ensure the catalytic converter has ot the maximum conversion ratio or the emissions of HC CO and NOx Principle The element of oxygen sensor Is composed of a ceramic tube the atmosphere goes through inside of the tube and the exhausted gas vents from the outside This ceramic tube is a solid electrolyte after Output volt Us Tennan waves A Engine Electronic Control System Service Manual page 16 of 65 heating the catalyzer on the external wall activates various compositions in the gas to produce chemical reactions the diffuse of oxygen ion on the tube generates a potential difference between the internal wall and external wall i e a signal voltage which is proportional to the content of oxygen in the exhausted as eatures It has the advantages of leadproof little dependence on exhaust temperature rapid entrance into closed loop control after starting 1 Cable 2 Disc spacer3 Lower insulating m bush C aT 4 Protective sheath 5 Contacting wire n SS eee 6 Heating rod 7 Contacting shim 8 sensor seat 9 Ceramic probe 10 Protective tube Technical specification Tightening torque 40Nm 60Nm Protective tube 3 slots Operating temperature Ceramic probe exhaust 200 C 850 C Hexagon nut 570 C Cable outlet 250 C Connectors 150 C Temperature gradient in Ceramic probe Max 100k s Lifetime gt 160 000km General requirement Keep con
9. A C relay compressor and related harness Engine Electronic Control System Service Manual page 23 of 65 Function expression Function description ECU controls the A C relay i e switches indirectly on or off the compressor subject to various input signals and operation condition of the engine General requirement Keep all switches and harness in good contact and perfect condition The other requirements refer to the chapter about air conditioner 3 Fault diagnosis Summary Engine Electronic Control System Service Manual page 24 of 65 To the engine F series ECU of the Electronic Control engine management System has equipped with a memory for storing faults information During operation ECU continues to perform the self diagnosis on the relevant parts and their work conditions of the system it will record the faults or error codes into the memory as soon as any abnormal cases are found This stored information can be read out and gives the service persons some prompts on faults for easy and rapid elimination If the faults are caused by temporary cable breakage or poor contact such sort of faults will be recorded as an occasional fault The occasional fault recorded in the memory will be cleaned out automatically by ECU if it does not occur again within 40 times of engine starts If a setup error of air fuel ratio occurs the error will not be recorded within 4 minutes The fault information in ECU will be cleaned ou
10. Eliminate all faults determined by the fault diagnosis instrument 3 Check and eliminate the ignition circuit fault 4 Check and eliminate the fuel pressure fault 5 Check and eliminate the spray nozzle fault 6 Check the pressure in the cylinder 7 Check and eliminate the mechanical fault such as improper throttle gap Engine Electronic Control System Service Manual page 55 of 65 2 The idle speed of the engine is not steady or in poor performance The causes may be 1 Ignition time and ignition order are not right 2 There is something wrong with distributor ignition coil high tension wire or spark plug 3 The fuel or pressure is insufficient 4 The idle stepping motor does not operate properly 5 The throttle position sensor or coolant temperature sensor is out of work 6 The throttle cable has fault 7 There are some air leakage from various pipes mounted with intake manifold 8 The Canister Canister Purge control valve does not work properly 9 A self adaptive teaching is not performed by the controller 10 A C signal is not normal 11 Abnormal voltage 12 Mechanical faults such as lower pressure in the cylinder Repairing procedure 1 Make sure sufficient fuel in the tank 2 Eliminate all faults determined by the fault diagnosis instrument 3 Check and adjust the throttle cable 4 Check and eliminate the leakage fault to various vacuum hoses 5 Check and eliminate the
11. Engine Electronic Control System Service Manual KZE Bio BRERIZSRiiSiRZo Preface Chang an Co has newly developed the electronic fuel injection EFI engines F series Jiangling brand on the basis of the original Jiangling engines F series with the advanced electronic control technique of Germany Bosch Co This engine is designed as multipoint injection one equipped with an oxygen sensor for accurate control of air fuel ratio as well it is equipped with a catalyst to lessen the emission therefore not only the sufficient power and lower fuel consumption economical efficiency are obtained but the lower emission can meet the current strict regulations at home even more it can reach the extreme requirement of the emission regulations in the future It is a so called green and environmental protection engine When the engines of F series take experiments in severe conditions such as in extreme cold high temperature or high altitude area they are indicative of the characteristics of easy startup stead idle speed smooth acceleration large power and low fuel consumption Since either the engine or a c system can be controlled by ECU the a c amplifier can be omitted thus the performances of a c have greatly been improved It is believed that this engine will attract the customers all around the country along with it being put into the market This manual describes the structure of Electronic Control engine manag
12. Engine Electronic Control System Service Manual page 28 of 65 Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if the fault diagnosis instrument can communicate with ECU Check if power supply is normal YES The fault diagnosis instrument is normal Repair power supply circuit or ignition switch circuit Measure if the resistance between terminal C and ground is less than 0 52 Measure if the voltage between terminal A and ground is equal to that of battery Measure if the resistance between terminal B and pin No 55 of ECU is less than 0 59 Repair harness to terminal C Check the harness from terminal A to anode Check the harness from terminal B to pin No 55 of ECU Check if the fault diagnosis instrument is abnormal Replace ECU Replace the fault diagnosis instrument and the connecting wire Engine Electronic Control System Service Manual page 29 of 65 3 6 Intake pressure and temperature sensor circuit Circuit diagram Intake pressure and temperature sensor Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if the intake pressure and temperature sensor is abnormal The Intake pressure and temperature sensor i
13. ctors ECU Connectors Ground Special precaution To the vehicles e g SC6350C SC6331EAC equipped with the engines JL465Q5 displacement is 1 012L the pin No8 of ECU white with blue tracer should be connected to the ground permanently Fault diagnosis Disconnect the fuel Enriching enrich wire from the ground as a usual measure the voltage between the Enriching enrich wire and the ground the voltage should be less than 4 V if not check the harness for electric leakage Connect the Enriching enrich wire to the ground only if the power is insufficient on the plateau or the engine degraded 3 14 Ignition advance angle correcting circuit Circuit diagram ECU 51 a ar Engine Electronic Control System Service Manual page 37 of 65 Fault diagnosis When the engine runs properly disconnect the connector check the ignition advance angle with ignition timing lamp at various running speeds in this case the angle should have a greater change otherwise check if the lead of pin No51 connects to the ground or has some leakage to the ground 3 15 Idle stepping motor circuit Idle stepping motor Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if there is any fault information on the Check if the idle stepping idle stepping motor motor runs smoothly Check if the connectors and harness are Check and re
14. ctors any dirt and corrosion 17 Measure if the voltage of battery is equal to or over 11V before check the electric system and measure circuit voltage 18 When installing the electronic devices such as antitheft device wireless or mobile telephone the following points will be observed 1 The antenna will be placed to the Electronic Control engine management System as far as possible 2 Do not connect any other wire onto the harness of Electronic Control engine management System 19 When the vehicle is in demand of weld or bake remove the ECU before doing so 20 This manual is suitable for the electronic control engine MPI engine F series Jialing brand and the relevant vehicle Chang an brand Engine model Vehicle model JL465Q5 SC6350 FHA SC6331E ECA SC1020A JL465Q7 SC6350C FAA SC6331 EYA SC6330C FAA SC6330DA Engine Electronic Control System Service Manual page 6 of 65 JL462Q3 SC1011D SC6320A SC633DB JL368Q3 Horizontal SC7080A JL368Q3 longitudinal SC6331D SC1012C 2 Summary The Electronic Control engine management System of the engine F series is composed of 6 subsystems such as intake system fuel delivery system control system ignition system emission system and air conditioner system page 7 of 65 Engine Electronic Control System Service Manual yoyorig 2p duind jon que jon Josuas JOUY Josuas oinjesodurs yuR ood i 3 yod
15. e connectors 8 Dismantle the coolant temperature sensor 2 Check if the appearance is in good condition 2 if there is any corrosion to the connectors 3 Assemble Assemble it in inverse order of disassembly 2 Tightening torque 20Nm Engine Electronic Control System Service Manual page 51 of 65 4 3 4 Oxygen sensor 1 Dismantle 1 Disconnect the connectors 2 Dismantle the oxygen sensor K ar A a iD am j Big Wwa lt my i 4 z A ir a eM 2 Check ar ES if the appearance is in good eT a condition 2 if there is any chokage in the sensing hole 8 if there is any abnormal noise in the sensor 3 Assemble Apply little high temperature grease on the thread part but it is not allowed to penetrate the grease into the sensing hole 2 Assemble it in inverse order of disassembly Tightening torque 50Nm 4 3 5 Knock sensor 1 Dismantle 1 Dismantle the knock sensor from the cylinder block 2 Check if the appearance is in good condition 2 If there is any dirt or corrosion to the connectors 3 Assemble 1 Assemble the knock sensor direct on the cylinder block without any washer 2 Tightening torque 20Nm It must tightened to the specified torque Engine Electronic Control System Service Manual page 52 of 65 4 3 6 Main relay fuel pump relay and A C relay 1 Dismantle Dismantle the relays from the holders 2 Check if
16. e hose for fuel delivery system is a specific high pressure hose never use general purpose hose instead of the specific one As well the similar clamp is required to use 6 ECU self teaching function When first start of the engine is done after disconnection of the plug of ECU or the terminal of battery turn the ignition key to the ignition position and remain in this place over 10s then restart the engine If not the idle speed of the engine may be unsteady 7 Since the reliability of the Electronic Control engine management System elements is very high the possibility of fault is very small to the system elements In general do not repair or replace the elements before complete elimination of the mechanical faults 8 When a fault happens to the Electronic Control engine management System the most possible cause may come from the connectors or harness so lay stress on examination of connectors and harness 9 When it is necessary to disassemble the intake manifold the coolant must be drained out completely or the oxygen sensor and cleaner may be damaged 10 In general the wires and connectors are fastened with lock unlock the connectors before disconnect them otherwise the connectors may be damaged When reinstall the connector ensure the Engine Electronic Control System Service Manual page 46 of 65 connectors are in position by hearing a click 4 1 Intake system service 4 1 1 Throttle body Idle stepp
17. ectronic Injection Engine 2 2 Fuel delivery system It is composed of fuel tank fuel pump fuel filter fuel rail fuel pressure regulator fuel injector and fuel pipe etc Function expression Function description Fuel in the tank is pumped out to each injector through the fuel pipe Engine Electronic Control System Service Manual page 9 of 65 filter and fuel rail the pressure regulator integrated with the fuel rail has the function to keep the fuel pressure in the injector 300Kpa higher than that in the intake manifold and to let most fuel come back to the fuel tank through the return pipe The injector is controlled by ECU thus appropriate pressurized fuel injects into the combustion chamber close to the valve on the cylinder head General requirement The fuel filter is able to filter the impurity dust in the fuel with small pressure loss so as not to block the fuel injector The fuel pressure regulator is able to adjust the fuel pressure to a correct level subject to the pressure in intake manifold therefore the fuel can properly atomize in a good pattern Intake pressure To vacuum booster hose temperature sensor Return pipe Vi hose acuum ose To PCV hose fuel regulation 7 Fuel inlet EFI coolant temperature sensor Fuel rail Fuel pressure regulator Fuel injector Manifold amp fuel delivery system 2 3 Electronic Control engine management System It is composed of the follows 1 Var
18. ement System principles and functions of elements and components diagnosis of faults and procedure and method to eliminate typical faults In association with reading the related manual of the engine F series this manual can meet the need of the repairmen and give the engineers and technicians hints for reference The members of compiling group are Luo Jun He Jugang Yang Bailin Wen Chengfu Xu Shaowen Zhong Shixue etc During compiling the manual we have got a great support from the leaders Qing Jianzhong and Cheng Hongbing of the After sale Service Department Chang an Sale Co and from the relevant persons of UAES Co Shanghai Thanks to all the persons stated above in good faith All rights to Chongqing Chang an Automotive Joint Stock Co Ltd any republication without authorization will be punished Compiler Aug 2000 Content I Precautioi sie ogee heron genau ea sainadeaaaaas E RE AEREN E 4 2 S mmary es ene iain danas eee ere eee ava aye ae ane eae A A 6 Dol Intake systemi ienee oa ol a A aE SEEE 7 2 2 Fuel delivery SVSUCING 235508 Goin bie task ions Basen ait sovenacue 8 2 3 Engine electronic control system cceceeeeee eee eees 9 2 3 1 Throttle position Sens Ol lt 2sssvaxciesdssesigeees cies 11 2 3 2 Intake pressure and temperature sensor 12 Didi d Hall sensor a iasde cAekaed E aaa 13 2 3 4 Coolant temperature SeNSOT ce ccc eee eee eens 14 2 3 O
19. er pressure or valve lash 6 The intake pressure sensor works improperly 7 There is a fault on ECU Repairing procedure 1 Eliminate all faults determined by the fault diagnosis instrument 2 Check and eliminate the ignition system fault 3 Check and eliminate the fuel delivery system fault 4 Check and eliminate the intake and exhaust system 5 Check and eliminate the mechanical fault such as insufficient cylinder pressure 6 Replace the intake pressure sensor 7 Replace ECU Engine Electronic Control System Service Manual page 62 of 65 B o Engine Electronic Control System Service Manual page 63 of 65 1 A C evaporator temperature sensor 9 Ji fin Zi DVI TI 2 Coolant temperature sensor 3 Intake pressure and temperature sensor 4 Throttle position sensor 5 Hall sensor 6 Knock sensor 7 Oxygen sensor 8 Speed sensor 9 Air conditioner switch 10 Heater switch 11 Idle stepping motor 12 Spray nozzle in cylinder No 1 13 Spray nozzle in cylinder No 2 14 Spray nozzle in cylinder No 3 15 Spray nozzle in cylinder No 4 4 cylinder engine Canister Canister Purge control valve 3 cylinder engine 16 Canister Canister Purge control valve 4 cylinder engine 17 Powered fuel pump 18 Fuel pump relay 19 A C relay 20 Main relay 21 High tension coil 22 Ignition switch 23 Faults diagnosis interface 24 Battery
20. for leakage or chokage 5 Never disconnect the fuel delivery pipe between pump and nozzle before the fuel pressure drops down or the pressurized fuel will spray out 6 Since the engine is equipped with a catalytic converter unleaded gasoline can be used only 7 It must be prohibited to introduce the unburned fuel into the exhaust pipe or the catalytic converter will be damaged 8 Ignition spark test may only be performed as actual demand is required but the experiment duration is as short as possible with the throttle being closed 9 Never unplug the high tension lead of spark plug while the engine is running 10 Prevent the engine from flameout Engine Electronic Control System Service Manual page 5 of 65 11 When connecting or disconnecting the electric elements turn the ignition switch to Off position otherwise the element will be damaged 12 Do not touch the element pins with finger or the static electricity from body may burn out the element 13 When measuring the circuits a multitester with high input impedance is required to use 14 When measuring the circuits it is prohibited to pierce the isolating layer of the wire if in this way the insulatibity will be affected 15 When measuring the connectors pay more attention not to bend the pins 16 Observe the connection connecter conditions and check if any bent male pins and expanded sockets in addition check if any unlocked conne
21. ignition system fault 6 Check the chokage in the pipe for idle speed 7 Check and eliminate the fuel delivery system fault 8 Check and eliminate the A C signal circuit fault 9 Replace the distributor 10 Check and eliminate the mechanical fault such as improper cylinder pressure or valve lash Engine Electronic Control System Service Manual page 56 of 65 3 Insufficient power from the engine The causes may be 1 The throttle cable is not adjusted properly 2 The fuel pressure is insufficient 3 The spray nozzle has fault 4 The intake pressure temperature sensor and coolant temperature sensor does not work properly 5 The idle stepping motor does not operate properly 6 The ignition timing wire connects to the ground 7 There is something wrong with distributor ignition coil high tension wire or spark plug 8 Ignition timing adjustment is improper 9 Intake and exhaust are not smooth 10 Mechanical faults such as incorrect pressure in the cylinder clutch fault etc Repairing procedure 1 Adjust the throttle cable 2 Check the ignition timing correcting circuit 3 Eliminate all faults determined by the fault diagnosis instrument 4 Check and eliminate the fuel delivery system fault 5 Check and eliminate the ignition system fault 6 Check the intake and exhaust system 7 Check and eliminate incorrect pressure in the cylinder clutch fault Engine Electronic Control
22. ill make higher fuel consumption and deteriorate emissions Special precautions For the vehicles with JL465Q5 engines e g SC6350C THA SC6331E ECA the pin No 8 white with blue tracer wire should connect the ground at any time but the pin No 52 green wire hangs up as a rule 10 Ignition timing wire to the ground Function expression Function description The square plug close to the Enriching enrich ground wire must connect to the ground when ignition timing adjustment is performed with a timing lamp Do not adjust the ignition timing before ECU determines the ignition advance angle General requirement After complete adjustment of ignition advance angle do not forget to disconnect the plug or serious problems will occur such as insufficient Engine Electronic Control System Service Manual page 19 of 65 power and catalytic converter overheat 11 ECU controller Function expression Function description It is used to analyze and process the signals from various sensors and deliver the related commands to the actuators General requirement Prevent the controller from showering impacting shocking and overheating and avoid touching the ECU pins with finger keep the connectors in good appearance without dirt and corrosion o ring Function expression Function description AN 2 Screen i P P 3 Injector with plug It injects an appropriate mixed fuel close to pe the intake valve pr
23. ing JIE 6 Valveneedlewith armature General requirement gt 7 Valve seat with jet orifice It is required to atomize fuel in proper spray pattern and to keep the connector in good contact without dirt and corrosion 13 Ignition coil Function expression Function z 1 scription It generates high tension to the spark plug which can ignite the mixed gas in the combustion chamber at appropriate intervals General requirement The ignition coil is able to produce Engine Electronic Control System Service Manual page 20 of 65 14 Idle stepping motor sufficient high tension Prevent the coil from showering and keep the connector in good contact without dirt and corrosion Function expression Function description It is used to control the intake rate of bypass air according to the commanded current from ECU as a result the idle speed of the engine is regulated to run steadily General requirement Keep the stepping motor turning smoothly and prevent it from showering and oil stain and keep the connector in good contact without dirt 15 Canister Canister Purge control valve oe Function It is used to control the flow rate of reproduced gas in the evaporation emission system Principle The Canister Canister Purge in the evaporation emission control system absorbs the fuel vapor from the tank till the Engine Electronic Control System Service Manual page 21
24. ing motor Throttle position sensor lt Adjust throttle cable N To canister valve hose 1 Adjust throttle cable Adjust the cable nut so that the throttle can be opened or closed completely Read out the aperture width with the fault diagnosis instrument the reading is 0 when the throttle is fully closed and the reading is more than 80 when it is fully opened 2 Dismantle the throttle 1 Dismantle the cable from the throttle body 2 Disconnect the connectors of throttle position sensor and idle stepping motor 8 Dismantle the hoses of the air cleaner and canister 4 Dismantle the throttle body from the intake manifold 3 Check if the throttle rotates smoothly 4 Assemble the throttle body Assemble the throttle body in inverse order of disassembly pay attention to use of a good gasket for the throttle body Engine Electronic Control System Service Manual page 47 of 65 4 1 2 Idle stepping motor 1 Dismantle 1 Dismantle the throttle body 2 Dismantle the idle stepping motor 2 Check if it is clear 2 if it rotates smoothly 8 if the O ring is in good condition 4 if the re is any deformation and corrosion to the connectors 3 Assemble Assemble the idle stepping motor in the original position and replace the old O rings with good ones tightening torque 4 0 5Nm 4 1 4 Throttle position sensor 1 Dismantle 1 Dismantle the throttle body 2 Dismantle the thr
25. ion 8 Bonded connection Pressure range To turbine engine 25kpa 115kpa Max 250kpa Input voltage 5 00 5V Weight Approx 18g 27g Vibration resistance withstand Harmonic wave 250m s Peak 600m s Current 9mA Temperature sensor resistance at 20 C 2 5K Q 5 Operating temperature range 40 C 4125 C Trigger time 0 2ms Measuring error Measuring tolerance 1 5 pressure General requirement Keep the connectors in good appearance without dirt deformation and corrosion 3 Hall sensor in the distributor Hall sensor Function expression Function description It supplies ECU with engine speed signal and crankshaft phase signal these signals will be taken as a reference time for injection and ignition Engine Electronic Control System Service Manual page 14 of 65 Technical specification Power voltage Power Supply voltage within the following temperature 4 5V 30V 40 C 80 C 4 5V 24V 40 C 150 C Supply current when Uv 16V lt 21mA Output voltage when Uv 20V 0 Uv Output current 0 20mA Saturated output voltage lt 0 4V On off time at the point of 10 or 90 output voltage dus Operating ambient temperature 40 C 130 C Limiting temperature in short term 40 C 150 C General requirement Keep the connectors in good appearance without dirt deformation and corrosion 4 Coola
26. ion timing adjustment wire 3 Observe the ignition timing signal from the cylinder Nol in aid of ignition timing lamp adjust the distributor to obtain that the ignition advance angle is 71 4 Disconnect the ignition timing wire from the pin No51 of ECU hang it up Notice It will make a serious problem if the ignition timing wire is not disconnected from the pin No 51 of ECU 4 6 Air conditioner control system Refer to the fault diagnosis Engine Electronic Control System Service Manual page 54 of 65 4 7 Check procedure of primary fault Notice Check coolant machine oil fuel and voltage before repair the engine 1 It is difficult to start up the engine or not able to start it The starting motor works normally The causes may be 1 There is no fuel in the tank 2 The fuel pump or other circuits are abnormal 3 The fuel pressure regulator is out of work 4 The fuel delivery line or spray nozzle is choked 5 The idle stepping motor does not operate properly 6 The intake pressure temperature sensor and coolant temperature sensor does not work properly 7 Ignition time and ignition order are not right 8 There is something wrong with distributor ignition coil high tension wire or spark plug 9 The main relay and fuel pump relay have got fault 10 ECU has broken 11 The Intake line is choked 12 The other mechanical faults Repairing procedure 1 Make sure sufficient fuel in the tank 2
27. ious sensors that are used to probe the running status of engine and other information demanded for proper work Engine Electronic Control System Service Manual page 10 of 65 2 ECU which is used to analyze and process the output signals from the sensors and control the actuators 3 Various actuators that are controlled by ECU 4 Harness which is used to connect sensors ECU and actuators Sensors Controller Actuators Fuel injector Throttle position sensor Ignition coil Manifold pressure sensor Intake temperature sensor Idle stepping motor Hall sensor CPU Canister Purge valve Coolant temperature sensor Main relay Harness Oxygen sensor Fuel pump relay Knock sensor Air conditioner relay Various switches Vehicle Speed sensor Air conditioner sensor bntrol e series Relational table of input and output signals of electronic control engine MPI engine F series Actuators Output signals 5 _ _ 2 z 5 5 5 gt P gt 5 9 on oOo S 2 s g pD g Si p g m 3 g H l aS Q 5 So D a a oO 2 E 2 amp S s 2 Input signals z 5 2 3 is Pi us a O Throttle position sensor P E IO Ome O Manifold pressure sensor R olololo Intake temperature sensor P ololo Hall sensor O O O O O Coolant temperature sensor p Ox 20 0 O O Oxygen sensor yg O Knock sensor O O Engine Electronic Control System Service Manual page 11 of 65
28. it 0 0 0 0 28 3 7 Throttle position sensor CIrCUit 00 cee cee cece eeee ee oreco 29 3 8 Oxygen sensor CMCUI io iia ihm oieeheeieereeieaewe ciendia 30 3 9 Hall SCHSOR Cit CU toes oat ce aly cts a araa e wend pataas 31 3 10 Coolant temperature sensor Circuit c cece eee cee 32 3 11 Knock sensor Cit CUit 2 necece es ad chivas taker enue ene ees 33 3 12 Speed SEMSOr CIRC sone nds Ae ld tey euusau oat te Neds ead uae 34 3 13 Enriching mixture gas circuit at high altitude 35 3 14 Ignition angle correction CircUlt ccc eee cece eee ee cee 35 3 15 Idle adjustment stepping motor circuit 008 36 3 16 Canister purge control valve CC El tan Sey ae Eh Sam cide aes gee eS tap Oe TD 3 17 Fuel injector cite 2 diac Seeyatnrerete eRe Savvees rererere 38 3 18 Powered fuel pump circuit c ccc cece eee e eee serere 39 3 19 Main Relays CHROMIC asenin soles oa utar la aadual tl Olle Dine 40 3 20 Ignition coil CIrCUit pcscan deen cecine eee eit pvencesiaisan dewvlebon 41 3 21 Air conditioner control Circuit c cece cence cence eens 42 AP Fault Clini a hOM essa cee e tes hayes lt Rane A SG BONA eo SE a aas 44 Ay Intake syste iaer t ae e gees eau hon at Aone SE ni 45 4 1 1 Throttle body dismantle check and assemble 45 4 1 2 Idle stepping motor dismantle check and assemble 46 4 1 3 Throttle pos
29. ition SCNSOM sx carsscn te ci ay aceon ssewecaseads 46 4 1 4 Intake anit ooo lotsa ste ni esa ees Gseean scutes 47 4 2 Fuel delivery SVStCM yes ih ceca vines iaveaiicaheredhitenweigreeee 47 4 2 1 Check fuel Pressure asiuedacsacctaovighiad dias rinas 47 Engine Electronic Control System Service Manual page 3 of 65 42 2 Check AUG SPs os sos Sei m ete alee ots 47 4 2 3 Check fuel pressure regulator cee eee neers 47 4 24 Check Mel injector sseni oria Git iaetesttedinwdisess 47 4 3 Electronic Control engine management SAA tC Ak aie ce yews ale aug ed dene ee Ses eee Bnew a OB 4 3 1 ECU dismantle assemble cccee eee e ees 48 4 3 2 Intake pressure and temperature sensor 4 49 4 3 3 Coolant temperature Sensor cce eee eeee eee ees 49 434 ORV OCD SENSO guts cvs u acts eee cage ee ada donee a 50 4 3 5 Knock SCHSOT 5 icc wielisek coder devas Garibad tec yoewentons 50 4 3 6 Main relay fuel pump relay A C relay 51 4 4 Emission control system cccece ence eeee sense enaees 51 4 4 1 Check canister purge control valve 00cee eee 51 4 5 lenition Systemi lt wavccecssexe co tenu ia neces aE AN 52 4 5 1 Distributor SyVStem jont2teacuve deny ive Ail seth ater dle taken 52 4 5 2 Ignition spark inspection c cece cece ence eeeees 52 4 5 3 Ignition timing adjustment
30. l pressure regulator or spray nozzle 3 The catalytic converter is not fully preheated 4 The catalytic converter has degraded 5 The engine does not run at a normal temperature 6 The oxygen sensor has fault 7 There are some air leakage from exhaust system 8 The throttle position sensor or coolant temperature sensor does not work properly 9 Ignition time is not right 10 Intake and exhaust are not smooth 11 There is a fault on ECU 12 Other mechanical faults Repairing procedure 1 Eliminate all faults determined by the fault diagnosis instrument 2 Check and eliminate the ignition system fault 3 Make the engine and catalytic converter to reach the normal temperature 4 Check and eliminate chokage and leakage faults in intake or exhaust system 5 Replace the catalytic converter or oxygen sensor 6 Check and eliminate the fuel delivery system fault 7 Check and eliminate the mechanical fault such as insufficient cylinder pressure Engine Electronic Control System Service Manual page 61 of 65 8 Self adaptive value exceeds lower and upper limits The causes may be 1 Intake and exhaust system are not smooth or they are leak 2 The fuel pressure regulator spray nozzle do not work properly 3 There is something wrong with distributor ignition coil high tension wire and spark plug 4 The oxygen sensor has fault 5 There are mechanical faults such as improper cylind
31. nectors in good appearance without dirt deformation and corrosion It is required to exist no breakage to the lead no abnormal noise when shaking the sensor and no oil stain at the end of the oxygen 6 Knock sensor Function It is used to check knocks from cylinder block so that the operation condition of the engine is able to be identified by the electronic controller Principle The knock sensor is a vibration acceleration sensor One or more are mounted on the cylinder block The pressure sensitive element of the sensor is a a 5 2 Engine Electronic Control System Service Manual page 17 of 65 Technical specification a piezoquartz When the engine is knocking the vibration delivers to the piezoquartz from a probing piece in the sensor A voltage is produced at the electrodes of the piezoquartz under the action of the vibration thus the mechanical vibration transduces into the output voltage signal Features It has the advantages of compact and secured structure high sensitiveness Frequency range 1kHz 20kHz Measuring range 0 1g 400g Sensitiveness at 5kHz 26 8mV g Linearity between 3kHz and 15kHz 15 comparable to 5kHz Primary harmonic frequency gt 20kHz Impedance gt 1MQ Capacitance 800 1600pF Temperature coefficient of sensitiveness lt 0 06mV g C Operating temperature 40 C 130 C General requirement Keep connectors in good appearance
32. nt temperature sensor Function It is used to measure the coolant temperature and intake air temperature Principle In the sensor there is a NTC thermistor its resistance will drop when the temperature rises The variation of coolant temperature or intake air temperature will result in the change of resistance then the varied resistance will be transduced into a voltage signal with a divider circuit and send to the controller Engine Electronic Control System Service Manual page 15 of 65 Characteristics curve Diagram Structure chart 1 Connector 2 Case 3 NTC resistor R 5 3 A 2 3 amp a to oO m 4 ae a ee ee r 20 0 20 40 60 80 100 120 Temperature t Technical specification Measuring range 30 C 130 C Max measuring current passed through sensor 5mA Nominal resistance at 20 C 2 5K Q 5 Max energy loss at 23 C static water A T 1K 15mW Nominal voltage 5V Vibration resistance withstand 600m s Response time in water Approx 15s General requirement Keep the connectors it in good appearance without dirt deformation and corrosion 5 Oxygen sensor Function It is used to determine if the mixture gas mixture is in the state of complete combustion by means of measuring the content of oxygen The electronic controller executes a closed loop control to realize the purpose of the excess air coefficient 1 according to the information from
33. of 65 fuel vapor has saturated The electronic controller opens the Canister Canister Purge control valve to mix the fresh air and saturated fuel vapor and form reproduced gas flow which is introduced into the engine intake pipe Depending on the engine running conditions the solenoid coil in the valve controls the aperture width of the valve by means of the duty ratio of impulse signal delivered from the electronic controller In addition the aperture width is also effected by the pressure difference between two ends of the valve Features it has the advantages of wide operating range accurate control to flow rate and good tightness System diagram 1 From tank 2 Canister 3 Atmosphere 4 Canister control valve 5 To intake manifold 6 Throttle AP isa pressure difference between ambient pressure Pu and intake manifold pressure Ps Technical specification Flow rate 2 or 3 m2 h at 200mbar Air tightness lt 2000cm2 h Control frequency 30Hz Min control pulse 7ms Current consumption 0 5V at 13 5V Resistance 26Q Operating voltage 9V 16V Inductance 48mH f 1kHz Operating temperature 30 C 120 C General requirement Keep the connectors in good contact without dirt chokage and leakage 16 Main relay fuel pump relay A C relay Function expression Function cription They are used to turn on or off the related Asahues e mrs ia Engine Electronic Cont
34. ottle position sensor 2 Check if the O ring is in good condition 2 if the re is any deformation and corrosion to the connectors 8 if the throttle shaft is assembled with tight fit 4 Assemble Assemble the throttle position sensor into the original position tightening torque 2 0 5Nm Engine Electronic Control System Service Manual page 48 of 65 4 1 3 Intake manifold Check 1 if there is any crack 2 if there is any leakage or chokage to the pipes which connect with the intake manifold 4 2 Fuel delivery system 4 2 3 Check fuel pressure 1 Connect a pressure gauge to the fuel delivery pipe with a 3 way 2 The pressure should be 2 5 bar at idle speed and the pressure is about 3 bar when the vacuum hose of the pressure regulator is removed 4 2 4 Check fuel pump if the fuel pump operates normally 2 if the fuel pressure meets the requirement 8 if the fuel filter is clear 4 2 5 Check fuel pressure regulator Check the fuel pressure 2 Check the vacuum hose of the pressure regulator 4 2 6 Fuel injector 1 Dismantle Disconnect the connectors 2 Dismantle the vacuum hose 8 Unscrew the mounting screws of the fuel distribution pipe 4 Dismantle the fuel injector with the fuel distribution pipe 2 Check if the spray orifice is clear without chokage 2 if the O ring is in good condition 8 if there is any deformation or corrosion to the connectors 4 The fuel dripping rate is les
35. pair connectors normal and harness Replace idle stepping motor Engine Electronic Control System Service Manual page 38 of 65 3 16 Canister Canister Purge control valve circuit Circuit diagram Canister control valve Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if there is any fault information on the Check if canister control canister control valve valve is choked or leaks YES Check if the connectors and harness are Check and repair connectors normal and harness NORMAL Replace canister control valve Engine Electronic Control System Service Manual page 39 of 65 3 17 Injector circuit Circuit diagram Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch ECU l mem Injector No 2 Sad A N 1 _ inns Check if there is any fault information on the injector Check if the connectors and harness are normal Replace injector To fuel pump relay Injector No 1 Injector No 3 NO Check if the spray pattern is normal Check and repair connectors and harness Engine Electronic Control System Service Manual page 40 of 65 3 18 Powered fuel pump circuit Circuit diagram Fuel pump relay To battery anode To main relay To other circuit at ILS ee IEH LA YAI NIH e
36. re in good contact NO Make the connectors in good and reliable contact YES Check if the circuit is normal Check and repair circuit YES Check if the resistance between pin C and pin D YES The oxygen sensor is normal is too small NO Replace the oxygen sensor Engine Electronic Control System Service Manual page 32 of 65 3 9 Hall sensor circuit Circuit diagram 1 a ECU 49 Hall sensor Fault diagnosis Turn on ignition switch and measure the engine speed parameter with the reading function of the fault diagnosis instrument Check if the engine can start Hall sensor circuit is normal Check if the fault diagnosis instrument can read out engine YES speed while running Check if the connectors and harness Eliminate the circuit fault are normal Replace Hall sensor distributor assy Engine Electronic Control System Service Manual page 33 of 65 3 10 Coolant temperature sensor circuit Circuit diagram Coolant temperature sensor Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if there is any fault information NO on the coolant temperature sensor Check if the connectors and harness are Check and repair the normal connectors and harness Read out the coolant temperature with the fault diagnosis instr
37. rol System Service Manual page 22 of 65 apparatus according to the commands from ECU General requirement Prevent the relays from showering maintain the switches with smooth and reliable operation and keep the connectors in good contact without dirt 2 4 Ignition control system It is composed of distributor assembly knock sensor ECU ignition coil high tension wire and spark plug Function expression Function description ECU is used to estimate the relevant operation conditions of the engine depending on the input signals from various sensors and deliver the relevant ignition signals to fire the mixed gas in the combustion chambers of the engine for a normal run General requirement Keep the elements and spark plug in good condition and reliable contact Adjust the timing reference of ignition properly remain clear in the distributor assembly and no looseness for the signal panel 2 5 Emission control system It is composed of activated carbon canister Canister Canister Purge control valve PCV catalytic converter and related pipes Function expression Function description It is used to lessen the fuel vapor the emission from crankshaft and tail gas pollutant General requirement Keep the all components in good condition and keep the line in air tightness without any chokage and leakage 2 6 Air conditioner control system It is composed of A C switch fan motor switch temperature sensor of evaporator ECU
38. s normal Check if the harness is in good contact with connectors Check if the harness connects with the circuit properly Replace the Intake pressure and temperature sensor Check and replace harness and connectors Check and repair the relevant connectors Engine Electronic Control System Service Manual page 30 of 65 3 7 Throttle position sensor circuit Circuit diagram Throttle Position sensor Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if there is any fault information on the throttle position sensor Check if there are any broken circuit or short Eliminate the circuit fault circuit for connectors or harness Read out the aperture width of throttle with the fault diagnosis instrument Check if it is equal to the actual aperture width The throttle position sensor circuit is normal Check if the throttle position sensor is installed Replace throttle position sensor with the throttle shaft properly Replace throttle body assy Engine Electronic Control System Service Manual page 31 of 65 3 8 Oxygen sensor circuit Circuit diagram TPA To fuel pump sensor Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch NO Check if there is any fault information on the oxygen sensor YES Check if the connectors a
39. s than 2 drip min when the fuel pressure is 3 bar Start the engine after connection connecter of plugs check if the spray pattern of atomized fuel is uniform to each injector and in good shape 3 Assemble Apply little grease on the O ring to the spray nozzle 2 Assemble it in inverse order of disassembly Engine Electronic Control System Service Manual page 49 of 65 4 3 Electronic Control engine management System 4 3 1 Dismantle and assemble the connectors of ECU 1 Dismantle Unlock the connectors 2 Rotate the plug 8 Pull out the plug 2 Check if there is any deformation or corrosion to the connectors 3 Assemble Assemble it in inverse order of disassembly and lock the plug in position Engine Electronic Control System Service Manual page 50 of 65 4 3 2 Intake pressure and temperature sensor 1 Dismantle Disconnect the connectors 2 Dismantle the mounting UES 8 Remove the sensor Yi pe fi belt ae Intake pressure amp temperature sensor 2 Check i if the O ring is in good condition 2 if there is any deformation or corrosion to the connectors 8 if the sensor is clear 3 Assemble Apply little grease on the O ring 2 Assemble it in inverse order of disassembly 8 Tightening torque 7 1Nm 4 3 3 Engine coolant temperature sensor 1 Dismantle Drain the coolant from the engine 2 Disconnect th
40. strument 2 Check and eliminate the ignition system fault 3 Check and eliminate the fuel delivery fault 4 Check and eliminate the other mechanical faults Engine Electronic Control System Service Manual page 59 of 65 6 Fuel consumption is too high The causes may be 1 There is something wrong with distributor ignition coil high tension wire or spark plug 2 Ignition timing adjustment is improper 3 The fuel pressure regulator spray nozzle do not work properly 4 The throttle position sensor or coolant temperature sensor does not work properly 5 There is a fault on ECU 6 Intake and exhaust are not smooth 7 The fuel Enriching enrich wire connects to the ground 8 Intake pressure and temperature sensor is choked 9 There is air leakage in front of or near the oxygen sensor 10 Other mechanical faults Repairing procedure 1 Eliminate all faults determined by the fault diagnosis instrument 2 Check and eliminate the ignition system fault 3 Check and eliminate the fuel delivery system fault 4 Check and eliminate the intake and exhaust system faults 5 Check and eliminate mechanical faults such as insufficient pressure in the cylinder Engine Electronic Control System Service Manual page 60 of 65 7 The emission exceeds limits The causes may be C1 There is something wrong with distributor ignition coil high tension wire and spark plug 2 The fuel delivery system has fault on fue
41. t if the power supply is cut off e g unplug the controller or disconnect the lead on the terminal of the battery Notice 1 If it is necessary to cut off the power of ECU during repair at first read out and record various fault information in the memory of ECU 2 Clean out the fault information in the memory and read out the fault information again after trial drive pay more attention to the repeated faults and check them carefully 3 The fault diagnosis instrument can only clean out the fault information in ECU instead of fault elimination Engine Electronic Control System Service Manual page 25 of 65 3 1 Read out and clean the self diagnosis information in ECU To read out or clean the self diagnosis information in ECU please use the fault diagnosis instrument for electronic injection system recommended by Chang an Co do not operate it before reading its instruction manual carefully The diagnosis interface is placed under the driver seat or near the girder it bands together with the Enriching enrich ground wire and ignition timing wire The fault information in ECU can easily be read out and cleaned just connect the interface with that of the fault diagnosis instrument and turn on the ignition switch Notice To read out the fault information in ECU correctly it is best to take a trial run 1 Trial run The trial time must be longer than 4 minutes Trial run must be taken for 3 minutes at
42. there is any corrosion to the connectors 2 if there is any oil stain 8 if the pins No85 86 of the relay are in open circuit 3 Assemble Assemble the relays in the original direction 2 It is allowed to alternate the three relays 4 4 Emission control system 4 4 1 Canister Canister Purge control valve 1 Dismantle Disconnect the connectors 2 Dismantle the inlet and outlet hoses 8 Dismantle the Canister Canister Purge control valve 2 Check if the appearance is in good condition 2 if there is any air leakage and chokage 3 Assemble Assemble the Canister Canister Purge control valve in inverse order of disassembly 2 Connect the inlet and outlet hoses to the manifold Engine Electronic Control System Service Manual page 53 of 65 4 5 Ignition system 4 5 3 Distributor assy Check if there is any looseness or play to the distributor disc or any high tension leakage from the distributor and check if the distributor cap is tightened in position and the distributor track is in good condition 4 5 4 Spark test 1 Disconnect the connectors of the injector 2 Connect the spark plug to the high tension damping wire or ignition coil connect the spark plug shell to the ground 3 Start the engine to check the spark generated by the spark plug 4 5 5 Ignition timing adjustment 1 Start the engine and keep the engine running at idle speed 2 Connect the pin No 51 of ECU to the ground with an ignit
43. tronic Control System Service Manual page 42 of 65 3 20 Ignition coil circuit Circuit diagram To ignition switch High tension coil ECU High tension wire Fault diagnosis Turn on ignition switch Ignition coil works properly Check if the engine is started properly Check if the spark test of high tension wire is normal Check the connectors and harness Check and repair the connectors and harness Replace high tension coil distributor and ECU Engine Electronic Control System Service Manual page 43 of 65 3 21 Air conditioner control system circuit Circuit diagram A C relay To compressor E ee ee To battery anode gt To main relay To A C switch and heater switch circuit A C condenser temperature sensor Fault diagnosis 1 Diagnosis on A C condenser temperature sensor Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if there is any fault YES Check if the Check and repair information on the A C connectors and the connectors and condenser harness are normal harness Measure if the resistance of temperature 4 Replace the temperature sensor is about 2K at ambient temperature A sensor and the resistance decreases while the temperature rising The temperature sensor circuit of A C condenser is normal Engine Electronic Control System Service Man
44. ual page 44 of 65 2 Diagnosis on the voltage between the pinNo40 and pin No41 of ECU When the A C switch and heater switch are turned off simultaneously The engine will increase 100 rounds at the idle speed the voltage should be less than 0 5V from the pin No41 and Pin No40 to the ground in other case such voltage is equal to power supply otherwise check the relevant circuits 3 Diagnosis on A C relay After finishing steps 1 and 2 above perform the following diagnosis The engine has run steadily Turn on the A C and heater switches Check if energized click of A C relay is Check if any voltage heard outputs from A C relay Check if the connectors and harness are Check and repair the normal connectors and harness Replace A C relay Engine Electronic Control System Service Manual page 45 of 65 4 Fault elimination Special precaution 1 When measuring the cylinder pressure The Hall sensor plug must be disconnected from the distributor 2 When determining the operating condition to each cylinder just unplug the relevant fuel injector instead of disconnecting the high tension wire of spark plug 3 If it is necessary to dismantle the pipe joint the oil stain around the joint must be cleaned out carefully 4 The fuel delivery system is under pressure so when loosening the joint wrap the joint with a dry cloth to suck the fuel exuded from the pipe and remove the pipe carefully 5 Th
45. ument Check if the displayed temperature is Coolant temperature sensor equal to actual temperature circuit is normal Replace coolant temperature sensor Engine Electronic Control System Service Manual page 34 of 65 3 11 Knock sensor circuit Circuit diagram 1 sensor 3 Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if there is any fault information NO on the coolant temperature sensor YES Check if the connectors and harness are NO normal NORMAL Replace the nock sensor Knock sensor circuit is normal Check and repair the connectors and harness Engine Electronic Control System Service Manual page 35 of 65 3 12 Speed sensor circuit Circuit diagram Fault diagnosis Connect the fault diagnosis instrument with the interface and turn on ignition switch Check if there is any fault information on the speed sensor Check the On Off status between the pin No 9 of ECU and ground 4 times of On Off are required while flexible shaft turning one round Check and repair the connectors harness flexible shaft of speedometer and speed sensor Speed sensor The speed sensor circuit is normal YES Engine Electronic Control System Service Manual page 36 of 65 3 13 Plateau fuel Enriching enrich circuit Circuit diagram Conne
46. without dirt deformation and corrosion It is required to exist no breakage to the lead 7 Speed sensor Function expression Function description It is mounted in the speedometer to supply the ECU with the speed signal for accurate determination of the engine operation condition running at idle speed General requirement Keep the connectors in good appearance without deformation and corrosion It is required to exist no breakage to the lead Engine Electronic Control System Service Manual page 18 of 65 8 Air conditioner sensor Function expression Function description It is used to supply the ECU with the evaporator temperature signal for control of air conditioner relay and indirect control of the a c compressor General requirement The sensor must be placed in correct position to reflect the evaporator temperature It is required to exist firm connection and no breakage to the lead 9 Enriching enrich ground wires Nol No 2 i e pin No 8 of ECU white with blue tracer wire and pin No 52 green wire Function expression Function description Two round plugs are placed in front of battery under the driver seat for vehicle SC6350C or near the girder for other models If they are manually connected to the ground ECU will thicken the mixed gas automatically to obtain sufficient power in the plateau region with thinner atmosphere General requirement Never connect them to the ground if not necessary or it w
47. xygen SCUSOL js ot eas seye tata an E eee nies Sere eacaneks 15 2 3 6 Knock SSOTISOL ix ccpacicace dass igaweedawn nese dee shaadea eee 16 2 3 Ope de SENSOR closure te aire es ond E E ai 17 2 3 8 Temperature sensor on A C evaporator 65 17 2 3 9 Ground wires No 1 No2 for enriching mixture gas 17 2 3 10 Ignition correction ground Wire ceeee eee 17 2 3 11 Electronic control unit ECU 0 ccc cece cece eens 18 ZO ND Fuel MJet onenarena aia hi i a 18 2 313 Ignition COM coca s a sated aie ues aan A EEE 19 2 3 14ldle stepping Motor 2 dc0 00 idaeesdeeddeaakeiavesieere es 19 2 3 15 Canister purge VALVE cerrenevsas aiadaved eevneun yPashattaal ye 20 24 Teniton system se eneen ae eet nee 1S SN 21 2 a D Emission control SyS tE eee aS dee Peas a a a E as ace asa a wee ae 26AIC Control syste Miriann tea EE e eia 22 3 Diagnosis of faults nnununnnssssessseeenrreersssssssrrerrrer 23 3 1 Read out and clear self diagnostic fault information 24 Engine Electronic Control System Service Manual page 2 of 65 3 2 Read out status parameter of engine c eee ee ee eens 25 3 3 Diagnosis of connections and harness 00ceeeeeee 25 3 4 Power of engine electronic control system amp ignition switch circuit 25 3 5 SEU Cla SHOSHC CIRCUIT ossessione a e saunas 27 3 6 Intake pressure and temperature sensor circu
48. y Ground Powered pump Fault diagnosis Turn on ignition switch Check if click of relay is heard Check the power supply when turn on or off ignition switch and main relay circuit Check if the connectors and Check and repair connectors and harness Replace fuel pump relay Check if the released click is heard till the ignition switch harness are normal remains on for 3s YES Powered fuel pump circuit Check if the running noise of pump YES Check if any pressure is heard within 3s after the ignition exists in fuel outlet switch turns on works properly NO Check if the fuse or harness is Check if the pump is normal Connected inversely Correct it Replace powered pump Repair harness or replace fuse assy Engine Electronic Control System Service Manual page 41 of 65 3 19 Main relay circuit Circuit diagram Main relay 37 ECU To other circuit To battery anode gt Fault diagnosis Repeat to turn on ignition switch Check if energized or released click of YES Check if the main relay relay is heard supplies power NO Check if the ignition switch and power Check and repair ignition and supply circuit are normal power supply circuit YES Replace the main relay IF NO CLICK Replace ECU Engine Elec
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