Chery QQ Maintenance Manual 372 EFI System
Chapter 1 The princple for EFI and actuator
1.Intake air pressure and intake than the up limit or lower than lower limit,ECU Temperature sensor will judge thar sensor is malfunction ( The intake Usage: Measure baro pressure in manifold and air pressure is below lower limit in starting, but intake air temperature to supply laod information ECU can juge sarting condition), “CHECK for engine. ENGINE”light will on at same time and engine Constitute and pricinple:The sesor will run at malfunction mode. ( The light will not Consisits of two sensors, MAP and IAT, which on for all malfunctions). mounted on voltage stablizer box. MAP: Map consisits of one silicon chip that etched a film on the chip. There are 4 piezoelectirc resistances that consist of a Wiston bridge. The information processing circuit is also on the chip. The chip consists of closed reference space with a metal shell. The air absolute pressure in the space is nearly to zero. In this way, a micro electric-mechnic system is formed. The active face of the chip is endured a pressure nearly to zero, and MAP pressure applies MAP/ IAT on the back of the chip through a connecting pipe. The thickness of the chip is only several microns （ um），so the change of MAP pressure will result the mechanical disform for the chip together with 4 resistances to change their resistance. The voltage signal that is linearity with pressure is formed after processing by information processing circuit in the chip. Intake air pressure: IAT is a resistor with NTC. Like coolant temperature sensor, the resistance
进气压力温度传感器 decreased with the temperature increasing. ECU in MAR/IAT engine monitors the change of intake air temperature (conresponding in series circuit). The circuit for MAR/IAT Diagnosis: The open, short or wear of sensor could Pins: No.1 Ground be ditected by the rear electronic unit of MAP. No.2 Output signal of temperature ECU will judge the malfunction of sensor if the No.3 To 5V out put signal exceeds the signal outside the curve No.4 Output pressure signal of output feasure.
For examle, if the intake air pressure is higher
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Chery QQ Maintenance Manual 372 EFI System
output
The section plane of MAP/IAT 1.Seal 2. Stainless steel bush 3. PCB plate 4. Sensor 5. Shell6. Support 7. Welding conncetion 8. Felt connection
2. TPS Usage: TPS is used to supply Throttle angle signal. According to this signal, ECU will receive enging 节气门位置传感器 TPS load signal and working condition signal such as starting, idle, back up, partial load, and full load) as well as acceleration and decelation signal. Diagram of TPS Consititue and pricinple:TPS is a angle sensor with 3. ECT TF-W linear output. It consists of 2 arc slide resistors and Usage: ECT is used to supply Coolant temerature 2 slide arms. The shaft of arm and throttle shaft information for the timing and fuel inject pulse connect to one axes. When running throttle, arm width control on engine start, idle, normal running. run together and slides on resistor. Putout UP as Constitue and pricinple: ECT is a termal sensive output voltage. resistor with ntc. The resistance decreases with So it is a angle potetiameter. ECU use UP/US as coolant temperature increase, but it is nor linrearity. ratio to vioid the fluctuate of sensor value caused The resistor is enclosed in copper bush. The by engine voltage fluctuate. change of resistance is transformed into changing Diagnosis: ECU check if throttle angle exceeds voltage to ECU by a voltage distribute circuit to the up limit or lower Limit of output signal. If so, monitor the change of water temperature. ECU will judge TPS malfunction, engine will run Diagnosis: When coolant temperature is over up at malfunction mode, MIL will on( Knock sensor limit, or below lower limit, MIL is on, engine run or dirty will cause engine malfunction). at malfunction mode. ECU control ignition and Install: Screw torque for bolts: 1.5Nm-2.5Nm fuel inject according to set temperature. Fan runs at high speed. Limit data: 2.5±5%KΩ Hint: Screw torque: 15±2Nm Hint: There are 2 sensors in vehicle. One is single pin water temperature and supply water temperature signal for water temp meter; The other Out view of TPS is double pins and supply the temp signal to ECU. Pins:1. Volt output 2. Signal ground 3. Signal
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Chery QQ Maintenance Manual 372 EFI System
onengine. The sense element is a piezoelectricity element. The vibration of cylinder is transformed to piezoelectrical crystal through mass block in
sensor. The pressure of crystal produce voltage on two polar faces and change vibration signal into output AC voltage signal. Because the frequency of vibration caused by engine knock is much higher than normal Diagram of ECT frequency of engine vibration signal, so ECU can Pins: There are 3 pins which could be distingquish knock and unknock signals after interexchangable. filtering the signal of KS. When engine load, speed a. EFI water temperature signal pin, resistance and coolant temperature exceed gate value, and not is 2.45KΩ at 200C. set KS malfunction information record, the signal b. Instrument water temperature signal pin, of KS will be used to close loop control for resistance is 0.05KΩ at 800C. knocking. When the control is actuated, the signal c. Signal ground of KS will input to ECU for integral after amplify and filter. When certain integral value in crank angle exceeds gate value, ECU will consider the knock happens, and reduce 1 degree of ignitionadvanced-angle. If knock happens on next cycle, ECU will reduce 1 degree of ignitionadvanced-angle again; If no b knocks happen in next cycles, ECU will resume the angle to normal value. Diagnosis: ECU monitors each sensor, actuator, power amplifier and check circuit. KS will mark malfunction position once following situations happen: KS malfunction 接仪表 KS control data process circuit malfunction Circuit diagram of ECT Cyinder identification signal is untrustable Hint: There are 1 water temperature sensor with 3 After KS marks the malfunction position, knock lines on it. One is ower line, two are signal lines close loop control will shut off and reduce 1 safty which one to ECU and the other to instrument. degree for ignition advanced-angle stored in ECU. When wrong frenquency is below set value, 4. KS malfunction position will resume. Usage: Supply knock signal to ECU for knock Hint: Screw torque 20± 5Nm. control. Consititution and principle: KS is vibration accelaration sensor mounted
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Chery QQ Maintenance Manual 372 EFI System
5. Oxygen sensor Usage: The sensor is used to supply the information that if oxygen is superfluous after the fuel in cylinder combused completely in intake air.ECU uses the information to close-loop control for quantitative fuel and transforms or purifies three venomousnee ingredients such as HC, CO and NOX in catalyzer. Constitue and priciple: The sense element is a ceramic pipe with bores. The outside of pipe is surrounded by exhaust of engine, and inside is touched with automosphere. The pipe wall is one kind of solid electrolyte with electric heating pipe KS with cable in it to heat ceramic body to 300 Cº for ceramic body to work.The oxygen ion can pass pipe freely. The concentration diffrencial is transformed into electric differencial with this feature to form electric signal. If mix air is richer, electric differencial and output voltage are higher; if mix air is leaner, electric diferencial and output voltage are lower. The working voltage of sensor fluctuates between 0.1-0.9V with 5-8 times every 10 seconds. Sensor is aging if the frequency is below this value and needs replacing. The sensor cannot be repaired. Disgnosis: ECU monitors each sensor, actuator, 爆震传感器 power amplifier and check circuit. ECU will mark the malfunction position for oxygen sensor once one of following situations happen: The diagram of KS Battery voltage is not trustable. MAP signal is not trustable. Pins: pin 1 and pin 2 connect ECU Injector driver is fault. The shield wire of sensor is folded on outside of After marking malfunction position for oxygen signal wire. sensor, fuel ration close-loop control will shut off and will be carry on according to basic inject time stored in ECU. Install hint: The screw torque of sensor is 50-60Nm. Smear anti-corsion oil on sensor after replacing.
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Chery QQ Maintenance Manual 372 EFI System
system. Sensors supply every signal for ECU. After caculation, ECU will control the action of
actuator such as injector and ignition coil to control engine operation. Constitute: There are shield shell and PC board in ECU. Many electronic control units are interated Oxygen sensor on the board to control EFI system. Install: ECU is double connector type and is fixed 主继电器 under instrument panel by screws. Series 372 only use one connector with 81pins.
氧传感器
The diagram of oxygen sensor Oxygen sensor connects with cable. The other end os cable is electric connector. There is asbestos Cover on outside. Pins on connector: No.1: Connect heat source (+)/white No.2: Connect heat source (-)/white No.3: Connect signal (-)/gray No.4: Connect signal (+)/black The heat coil of sensor is controlled by ECU. When sensor is heated to certain temperature, ECU will cut current to the coil and stop heating.( when open or short heating coil, ECU will find malfunction information and MIL will on. Engine will run under malfunction mode in some working conditions). 6. ECU Usage: ECU is central part of electronic control
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Chery QQ Maintenance Manual 372 EFI System
ECU pins: 1. Battery ground 29. CKP input 57. Not used 2. Battery ground 30. CMP ground 58. A/C apply 3. 3 Ignition coil 3 31.Water temperaturesignal 59.O2 ground 4. Ignition coil 1 32.TPS input 60. IAT ground 5. Ignition coil2 33. Not used 61. Injector of No.2 cylinder2 6. Can Bus lowCAN 34. Not used 62. Not used 7. Canbus highCAN 35. Step motor B+ 63. ECU powerECU） 8. O2 sensor 36. Step motor B - 64.High speed fan relay control output 9. Not used 37. Not used 10. KS signal 38. TPS ground 65. High Speed fan relay control output 11. Not used 39 Speed signal 66. Engine speed input signal 12. Evaporator temperature sensor input 40. Not used 67. Main relay control output 13. Evaporator temperature sensor ground 41. Not used 68. A/Crelay control output 14. Not used 42. Not used 69. Fuel pump relay output 15. Not used 43.O2 sensor 70. Trouble lamp 16. Not used 44. ECU power（+12V BAT） 71. Not used 17. Not used 45.TPS power supply（+5V） 18. Not used 46. IAT power supply（+5V） 19. Step motor A + 47. Not used 72. CKP input 20. Step motor A - 48 IAT ground 73. Water teperature sensor ground 21. Main relay power supply 49. Not used 74. Power steering pressure switch signal 22. Ignition switch power supply 50. 75. Not used 23. No.3 injection nozzle 51. Not used 76. Not used 24. No.1 injection nozzle 52 Not used 77. Diagnostic（K wire） 25. Not used 53. Not used 78. Not used 26. Canistor relay 54. KS ground 79. Not used 27. CKP ground 55. Ignition coil ground 80. Not used 28. Not used 56. IAT signal 81. Not used
Pins and out view of connector
7. Fuel pump interference elements). The pump and Usage: Fuel pump feeds fuel with certain motor are mounted on same shaft and pressure and quantity to engine. The sealed in same shell. Pump and motor in temperature and voltage have great influnce on pump. Constitute and principle: The pump shell are surouned by fuel for radiation and consistsof DC motro, vane motor and lubrication. cover( together with stop return valve, leak valve and anti-electromaganatic Battery supplies voltage to pump through
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Chery QQ Maintenance Manual 372 EFI System pump relay. The relay only switches on pump circuit during engine starting and 主继电Main 器relay 主电源 running. When engine stops for malfunction, Power pump will stop automatically. The maximum pressure on outlet of pump is desided by leak valve. Series 372 use non-return fuel system and fuel pressure 燃油泵继电器 regulator is mounted on pump assembly. The regulator adjusts pump pressure to Fuel pump relay 380kPa to adapt the requirment for system operation. The diagram of fuel pump Note: The temperature of fuel has great Pins: There are 2 pins on pump to connect influnce on pump function. When working pump relay. Marks “+”and“-”are cut on under high temperature for a long time, the the shell of pump. pump pressure will drop rapidly if fuel temperature is over certain value. If engine 8. Injector cannot be heat started, please check carfully Usage: Injector injects atomized fuel to whether the high temperature working engine in specified time according to function is good. instruction of ECU. Constitute and principle: ECU sends pulses to injector coil to form magnetic fiel force. When the force increased enough to overcome the resultant force of spring pressure, weight of needle valve and friction, needle valve begins to lift and inject process starts. The maximum lift height of needle valve does not exceed 0.1mm. When inject pulses stop, needle valve closes again by the pressure of return spring. Fuel pump Install hint: The injector must use suitable connector. Inorder to mounting easily, recommend to smear non-silicon clear oil on the surface of O-ring connected with fuel distribution pipe. Pay attention to not pollute internal injector and injector hole by oil. Install injector to the seat vertically to injector seat, then clamp injector on the seat by clip.
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Chery QQ Maintenance Manual 372 EFI System
Pins: There are 2 pins on each injector. One Note: For long stopped vehicle, please of pins marked (+) on side of shell connects check carefully if the fuel cohered blocks pin 87 on pump relay, and another connects injector. pin 23,24 or 61 on ECU.
Diagnosis: S11 EFI system does not 9. Step motor DLA diagnose the injector itself, but diagnoses for Function: Step motor with idle actuator injector driver. When injector driver is short offers by-pass intake air channel. When to battery voltage or overload, short to throttle closes, air will enter engine through ground or open, ECU will mark malfunction the channel. ECU can regulate the section of position. Oxygen sensor close-loop control chennel to adjust mass airflow and adjust and self-study pre-control will shut off. The inject fuel amount. When engine works, last self-study data is effective. After ECU will control step motor according to troubleshooting, malfunction position different working conditions to change the resumes. operation of engine. Constitute and principle: Step motor is a micro motor that consists of several steel stators and one rotor. A coil is reeled on each stator. Rotor is a perminent maganet with a nut on the center. All stator coils is always connected with electricity. If changing current direction in one coil, rotor will turn a degree. When current direction in each stator coil is changed in suitable order, revolutionary field is formed to run rotor in Injector certain direction. Disgnosis: ECU can monitor the short or open of two coils for step motor and lights MIL. Engine runs at malfunction mode. Some time use test can find the steps changing, but engine still does not work normally. Please check if intake air pressure changes to confirm is the piston of step 主继电器 motor works.
缸 缸 缸
喷油器组
The diagram of injector
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Chery QQ Maintenance Manual 372 EFI System
10. Ignition coil ZSK-ROV Function: Ignition coil transforms low voltage on primary coil into high voltage on secondary coil and produces sparks through spark plug to light fuel-air mix in cylinder. Independent ignition: There are 3 ignition coils on vehicle. ECU will control the ground of these coils according to the signal of crank position and cam position to control Step motor ignition of engine. Constitute and principle: Ignition coil consists of primary coil, secondary coil, iron core and shell. When battery voltage supplies on primary coil, the coil is charged. Once ECU cuts off the return loop of primary coil, charging stops. The high voltage is induced in secondary coil at same time. Diagnosis: ECU does not have diagnosis function for ignition coil. So if ignition coil is fault, DTC does not exist. It can judge if 怠速步进电机 the coil works normally only by checking The diagram of step motor resistance of ignition coil. Usually, ignition coil produces more heat during the working, but over heat of coil will result in increasing for coil resistance. It will cause unstable running and automatically stopping work for engine. Primary coil: 0.47 ohms. Secondary coil: 8 ohms.
Pins: Pin1: Connect pin 19 on ECU. Pin2: Connect pin 20 on ECU. Pin3: Connect pin 35 on ECU. Pin4: Connect pin 36 on ECU. Pin 1 and pin 2 are on one coil and pin 3 and pin 4 are on the other. The resistances in both coils are same. Please confirm if the resistance is in standard values.
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Chery QQ Maintenance Manual 372 EFI System
of clearing air. The out view of ignition coil( for 372, there 3 such coils) Diagnosis: ECU does not have diagnosis function for canister control valve, but can diagnoses canister control valve driver. When canister control valve driver is short to battery voltage or over load, short to ground and open, the basic self-study of fuel 主继电器 metering close-loop control is shut off. If canister solenoid is fault, engine will be unstable idle or over high idle.
The diagram of ignition coil( with distributor) Pins: There are 2 pins on low voltage side of coil. Pin marked (+) connects battery and the other connects ECU.
11. Canister control valve Usage: The valve is used to control flux to clean canister. The valve is controlled by Out view of canister control valve ECU according to engine load, lasting time and ferequency of puleses. The fuel vapor in canister will accumulate to leak fuel for 主继电器 polluting enviroment. The function of
canister solenoid is to open the solenoid to pass superfluous vapor into intake air pipe to be in combustioned. Constitue an principle: The valve consists of magnetic coil, iron core and vlave body.
There is filter on inlet. Mass flow through 炭罐电磁阀 the valve is related with the frequency of electric pulses that put out to control valve The diagram of canister control valve by ECU and with the pressure differencial TEV-2 between inlet and outlet. If no pulses, Pins: There 2 pins on canister control valve. canister control valve will close. ECU One connects pin 87 on main relay and the controls the electrify time for canister other connects pin 26 on ECU. solenoid to indirectly control the mass flow
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Chery QQ Maintenance Manual 372 EFI System
12. Steel fuel distribution pipe assembly Usage: To store and distribute fuel and return superfluous fuel into fuel tank. Injector and fuel pressure regulator are mounted on the tank to offer stable pressure circustance to balance the fuel pressure and amount of fuel for smooth running of engine.
Constitute: Series 372 fuel distribution pipe assembly consists of injector and fuel supply pipe aeembly. Since system does not use Fuel distribution pipe assembly return fuel control, there is no fuel pressure regulator.
Install request: Clamp in/out fuel pipe and rubber hose with clip. The type of clip should be matched with rubber hose to insure the seal between in/out fuel pipe and the hose.
Diagnosis: Usually, fuel supply pipe
assembly is seldom to be fault. Mostly bad installing causes the fuel leakage. Pay more attention during installation. Don’t install the seal or o-ring that are used.
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Chery QQ Maintenance Manual 372 EFI System
Chapter 2 Basic principle for diagnosis of EFI
(1) Fault information record ECU continually detect the sensors, actuator, related circuit, MIL and battery voltage as well as ECU itself, and carry on reliability test for sensor output signal, actuator drive signal and internal signal such as oxygen close loop control, knock control, idle control and battery voltage control. Once the malfunction in one point is found, or one signal is not true, ECU will set the malfunction information record on RAM memory. The record exists as DTC form and displays as the order of DTC appearing. Malfunction can de divided as stable malfunction or temporary malfunction such as the fault caused by short-lived, harness open or bad contact for inserters according to the frequency
(2) Malfunction statues If the lasting time for one malfunction detected exceeds stable time settled, ECU will consider it as a stable fault and stores it as “stable malfunction”. If it disappears, ECU will store it as “temporary malfunction” or “not existing”. If it is detected again, it will be “temporary malfunction”, but the existing history malfunction does not influence the normal use of engine.
(3) Malfunction types Short to positive pole of battery Short to ground Open (In the case of up or down resistors, ECU will identify the open fault in input terminal as short between input terminal and battery positive pole or short to ground).
(4) Limp drive home For some important faults detected, if their lasting time exceeds the setting stable time, ECU will apply some software methods, for example, to close some control function of oxygen sensor close loop control and set substitute value for some unbelievable value. At the moment, through the working condition of engine is not so good, but the vehicle can be drive home. In this way, vehicle can drive home or service station for repairing to void stop on road. Once the fault detected disappears and Hz deducted to 40, the normal values will be used again.
(5) Warning Some 372 of MS200 system vehicles equip MIL. When some important parts such as ECU, MAP, TPS, ECT, KS, O2, phase sensor, injector, idle actuator, 2 drive poles of step motor, canister control valve, fan repay are fault, ECU will turn MIL on and warning until the faults disappear.
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Chery QQ Maintenance Manual 372 EFI System
(6) Fault read out The malfunction information records can be read out from ECU by tester, or be read by flashing DTC codes. If the faults relate the function of fuel/air mix ratio regulator, engine will read malfunction information records after running at least 5 minutes.
Fig. 3 ISO 9141-2 Standard diagnosis connector The diagnosis connector install under glove box of sub cab
(7) Clear DTC When eliminate the faults, DTC should be cleared. There are 5 methods: Clear DTC by using tester with the order of “clear DTC”. Remove ECU terminals or battery terminals to clear DTC outside of RAM.
(8) Finding faults Getting above DTC means only to know the faults position, but not the real fault because the reason for one fault may be the electric or mechanical one such as sensor, ECU or actuator damage, or open circuit or short circuit or even mechanical damage.
Fault is internal, but the appearances are various. Firstly use tester or flashing light to check if existing any DTC, and troubleshoot the faults accord to DTC, then find the reason of fault according to engine symptom.
The step of fault diagnosis according to fault information record DTC 13 A/C evaporator outlet temperature sensor
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Chery QQ Maintenance Manual 372 EFI System
The diagram for A/C evaporator temperature sensor
No. Operation steps Test Next step results 1 Turn on ignition key. Next 2 Pull out connector of A/C evaporator Yes Next
temperature sensor, measure if the volt No 4 between 2 pins is 5V with multimeter.
3 Check any open or short between 2 pins Yes Replace sensor
with multimeter. No Replace ECU
4 ECU and harness, check any open or short Yes Repair or replace between pin 30 , 39 of ECU and pin (1) and harness (2) of sensor with multimeter. No Replace ECU
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Chery QQ Maintenance Manual 372 EFI System
DTC 14 TPS
The diagram of TPS
No. Operation steps Test Next step results 1 Turn on ignition key. Next 2 Pull out connector of A/C evaporator Yes Next temperature sensor, measure if the volt between 2 pins is 5V with multimeter. 5 No 3 Measure the resistance between pin (1) Yes Next and (2) if in 1.6 to 2.4k with multimeter. No Replace sensor
4 Run slowly TPS from one end to another Yes Replace sensor and check any open or short between pin (1) and (3). No Replace ECU 5 Connect adaptor between ECU and Yes Repair or harness, check any open or short between replace harness pin 12 , 30 of ECU and pin (1) and (2) of No Replace ECU sensor with multimeter.
KS
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Chery QQ Maintenance Manual 372 EFI System
爆震传感 器
Diagram for KS
No. Operation steps Test Next step results 1 Turn off ignition key, engine nor run. Next 2 Pull out connector of KS sensor, measure if Yes Next
the resistance between pin 1, pin 2 of sensor No Replace sensor is over 1M with multimeter. 3 Slightly knock around sensor with small Yes Next
hammer and check if any AC signals putout No between pin1 and pin2 of sensor. Replace sensor 4 Turn on ignition key but engine not run Next
Connect adaptor between ECU anfd harness Yes Repair or replace and check any open or short between pin harness 11, pin 30, pin19 of ECU and pin 1 and pin2 No 更换ECU and pin 3 with multimeter. Replace ECU
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Chery QQ Maintenance Manual 372 EFI System
DTC 18 IAT
进气压力温度传感器
Diagram of MAP and IAT No. Operation steps Test Next step results 1 Turn on ignition key. Next 2 Pull out the connectors on harness of Yes 4 MAP and IAT and check if the voltage between pin1 and pin 2 is 5V with No Next multimeter. 3 Connect the adaptor between ECU and Yes Repair or replace harness, check if open or short between harness pin 48, pin 46, pin 60 of ECU and pin 1, No Next pin 3, pin 4 separately with multimeter.
4 Turn on ignition key but engine not run Next
5 Put on N shaft and run engine in idle. Step Yes Replace ECU down accelarate pedal to fully open. Check if the voltage between pin 4 and No Replace ECU or pin 1 of sensor is incrasing to 4V with sensor multimeter.
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Chery QQ Maintenance Manual 372 EFI System
Oxygen sensor
主继电器
氧传感器
The diagramOxy ofg enoxygen sensor sensor No. Operation steps Test Next step result 1 Turn on ignition key. Next 2 Put out the connector on oxygen sensor and check Yes Next if the voltage between pin 1 and pin 2 is 12 V. No 4 3 Check if the resistance between pin 1 and pin 2 on Yes Replace ECU oxygen sensor is from 6 to 25. No Replace sensor 4 Check if the fuse in oxygen sensor heating circuit Yes Replace fuse is burn out. No Next 5 Check if open or short between pin 1 on sensor Yes Repair or replace and pin 87 on fuel pump relay, check open or short harness between pin 2 and pin 59. No Next 6 Insert the connector of oxygen sensor harness. Put Next N shaft and run engine in idle to normal coolant temperature. 7 Put out the connectors of oxygen sensor from Yes Next harness. Check if output 0.1-0.9V voltage between pin 4（+） and pin 3（-） Yes Repalce sensor 8 Connect the adaptor between ECU and harness. Yes Repair or replace Check if open or short between pin 43, pin 59 on harness ECU and pin 3, pin 4 separately No 更换 Replace ECU
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Chery QQ Maintenance Manual 372 EFI System
DTC 18 IAT
进气压力温度传感器
The diagram of MAP and IAT
No. Operation Steps Test Next step result 1 Turn on ignition key. Next 2 Put out the connectors on MAP and IAT Yes Next
harness.Check if the voltage between pin 1 No 4 and pin 2 is 5 V. 3 Check if the resistance between pin 1 and Yes Replace ECU
pin 2 is suit to the temperature ( see related No Replace sensor parts in this manual). 4 Connect the adaptor between ECU and Yes Repair or replace harness. Check if open or short between pin harness 30, pin 12, pin 44 on ECU and pin 1, pin 3, No Replace ECU pin 2 separately.
Coolant temperature sensor
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Chery QQ Maintenance Manual 372 EFI System
b
接仪表
The diagram of CTS
No. Operation steps Test Next step result 1 Turn on ignition key. Next 2 Put out the connector on CTS harness, Yes Next
check if the voltage between pin and pin c is No 4 5V. 3 Check if the resistance between pin a and Yes Replace ECU
pin c is suit to the temperature ( see related No Replace sensor parts in this manual).
4 Connect the adaptor between ECU and Yes Repair or replace harness. Check if open or short between pin harness 73, pin 31 on ECU and pin a, pin c No Replace ECU separately.
Injector
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Chery QQ Maintenance Manual 372 EFI System
主继电器
缸 缸 缸
喷油器组 The diagram of injector
No. Operation steps Test result Next step 1 Turn on ignition key without engine run. Next 2 Put out al connectors on injector harness; connect two Next probes of multimeter on pin 1 and engine ground. 3 Turn on ignition key. See if the display on multimeter Yes Repeat step 2 is 12 V for 1 second once turning on the key. Yes 6 No Next 4 Use multimeter to check if open or short between Yes Repair or replace pin 87 on pump relay output and pin 1 on each harness injector. No Next 5 Repair or replace pump replay, main repalay and Yes Repair or replace circuit. harness 6 Connect the adaptor between ECU and harness. No Next Check if open or short between pin 24, pin 61, pin 23 on ECU and pin 2 on each injector separately. 7 Use multimeter to check if resistance between pin 1 Yes Repeat step 7 and pin 2 on injector is 12—16V in 20 C. Yes Next
No Replace injector 8 Reinsert all injector connector. Put N shaft and run Yes Repeat step 8 engine in idle. Put out each injector connector in turn No Replace ECU and check if the vibration of engine becoe serious.
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Chery QQ Maintenance Manual 372 EFI System
Canistor control driver
Diagram of canistor control valve
No. Operation steps Test result Next step 1 Run engine in idle to normal coolant Next temperature. 2 Put out the connector on canistor valve and Yes Next check if the voltage between two pins is 12 No 5（Check live V. wire） 3 Reinsert conncetor of canistor valve Yes Next harness. Run engine to 1500 RPM. Touch （ valve with hand and check if any slightly No 7 Check ground ） viabration or impact on valve. wire 4 Use multimeter to check if resistance Yes ReplaceECU between pin 1 and pin 2 is 22—30. No Replace canister control valve 5 Use multimeter to check if open or short Yes Repair or replace between pin 87 on main relay and pin 1 on harness valve. No Next 6 Repair or replace main relay and circuit. 7 Shut off engine. Connect adaptor between Yes Repair or replace ECU and harness. Use multimeter to check harness if open or short between pin 26 on ECU and No Replace ECU pin 2 on valve.
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Chery QQ Maintenance Manual 372 EFI System
MIL driver
The diagram of MIL
NO. Operation steps Test result Next step 1 Turn on ignition key Next 2 Remove instrument panel. Put out MIL Yes Next bulb. Use multimeter to check if the voltage No 5（Check live in MIL socket is 12 V. wire）
3 Use multimeter to check if MIL bulb is Yes Next good. No Replace bulb. 4 Connect the adaptor between ECU and Yes Repair or replace harness. Check if open or short between pin harness 70 on ECU and input connector of MIL. No Replace ECU 5 Check if the fuse in oxygen heating circuit Yes Replace fuse is burn out. No Next 6 Use multimeter to check if open or short Yes Repair or replace between pin 87 on main relay and pin 1 on harness MIL socket. No Next 7 Repair or replace main relay and circuit.
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Chery QQ Maintenance Manual 372 EFI System
No. 1 and No.2 coil driver in step motor
怠速步进电机 The diagram of idle actuator/step motor
No. Operation steps Test results Next step 1 Turn on ignition key but engine not run. Next 2 Put out the connector on step motor and Yes Next check if the resistance between pin 1, pin No Replace idle 2,and pin 3, pin 4 is 40—80. actuator 3 Use multimeter to check if the resistance Yes Next
between pin 1 and pin 2 as well as Pin 3 and No Replace bulb or pin 4 are infinite. actuator 4 Use multimeter to check if voltages between Yes Replace actuator pin 1 and pin 2 as well as pin 3 and pin 4 are 12V. No Next 5 Connect adaptor between ECU and harness. Yes Repair or replace Use multimeter to check if open or short harness between pin 19,pin 20, pin 35, pin 36 on ECU and pin1,2,3,4 on step motor. No Replace ECU
6. The diagnosis steps according to engine symptoms Before beginning diagnosis steps according to engine symptoms, the primary checking should
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Chery QQ Maintenance Manual 372 EFI System be carried out: (1) Make any abnormal situation for ECU and MIL (except vehicle without MIL). (2) Use diagnoses instrument or flashlight to check to insure no any malfunction information records. (3) Use diagnoses instrument to check the idle data on heated engine of EFI system to insure everything is OK. (4) Make sure the sysptoms that driver told exisist and check the exact position of sysptom. Then begin appearance check: Check if clear or substance on harness ground. Check if any break, tweast in vaccum pipe or if connect correctly. Check if any block in vaccum pipe. Check if any stave or damage on intake air pipe. Check if the seal between throttle body and manifold is good. Check if any break, aging on high voltage line in ignition system or connect correctly. Check if the connection of wires is correct or any loose/bad contact on connector. 1） Engine does not run or run slowly on startin No. Operation steps Test step Next step 1 Check if the voltage between two poles on Yes Next battery is 10—12.5 V. No Repair or replace battery 2 Turn on ignition key. Check if the voltage Yes Next on positive poles of battery connected with No Repair poles or replace the key is 10—12.5 V. wires 3 Keep ignition key on start position. Check Yes Next if the voltage on positive pole of stater connected with ignition key is 8V. No Replace bulb, replace actuator, repair or replace ignition key 4 Keep ignition key on start position. Check Yes Next if the voltage on positive pole of stater is No Repair poles or replace 8V. wires
5 Use multimeter to check if open or short Yes Repair or replace start for starter. motor No Next 6 Check if engine blocks for bad lubrication. Yes Trouble shooting No Next 7 If in winter, check if the resistance of Yes Replace suitable oil starter is too big that resulted by wrong No Repair or replace timing lubricant or gear oil. belt
2）Engine can run but cannot start successfully (with distributor) No. Operation steps Check step Next step
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Chery QQ Maintenance Manual 372 EFI System
1 Turn on ignition key. Use tester to check if Yes Eliminate malfunction information record exisits. trouble No Next 2 Pull out cylinder wire and connect ignition plug Yes 8 with the electrode 5—10mm from engine body. No Next Run engine with starter and check if high voltage ignition in blue and white appears. 3 Check if the resistance of high voltage wire is Yes Next normal (about 16k/ m. For exact data, please No Repair or touch manufacture). replace high voltage wire 4 Check if any ablation damage or crack on Yes Replace distributor cove and distributor. No Next 5 Check if any loose or damage for identification Yes Replace ring in distributor. No Next 6 Check if ignition coil is normal. Yes Next No Replace 7 Check if distributor and high voltage coil Yes Next inserter is good. No Connect plug 8 Turn on ignition key. Check if fuel pump relay Yes Next and fuel pump can work for 3 seconds. No Repair fuel pump circuit 9 Connect fuel pessure gauge valve. Short pin 30 Yes Next on fuel pump relay and pin 87 to start fuel pump. Check if fuel pressure is 250—300 kPa. No 13 10 Pull out fuel distribution pipe together with Yes 12 injector. Pull out injector connector on harness. No Next Supply 12V voltage directly from battery to injector. Check if injector can inject fuel. 11 Re-check if injector can inject fuel after Yes Next cleaning. No Replace injector 12 Check If fuel deteroprate or containing water. Yes Replace fuel oil No 18 13 Check if fuel pressure below 300kPa. Yes Next No 17
14 Shut off fuel gauge valve. Connnect ignition key Yes Next again to run fuel pump for 3 seconds Check if
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Chery QQ Maintenance Manual 372 EFI System
again to run fuel pump for 3 seconds. Check if No 16 fuel pressure can be set up. 15 Check if fuel pipe is leaked or blocked. Yes Repair or replace fuel inlet No Replace fuel pump 16 Check returning fuel pipe is blocked or bend. Yes Repair or replace oil return pipe No Replace fuel pressure regulator 17 Connect adaptor between ECU and harness. Yes Next Check if voltage exisit on pin 1,2. Check if the positive source on above pins and ground wires No Repair or replace of pin 22,44,63 on ECU are normal. harness 18 Check if intake air system parts are leakage. Yes Repair No Next 19 Check if MAP or IAT are blocked. Yes Repair or replace No Next 20 Check if ECT is normal. Yes Next No Repair or replace 21 Check if engine cannot start because mechanical Yes Eliminate reason such as cylinder head spacing and malfunction cylinder leakage. No Replace ECU
3）Heat start difficult No. Operation steps Test results Next step 1 Turn onignition key. Use tester to check if Yes Eliminate trouble malfunction information record exisits. No Next 2 Connect fuel pessure gauge valve. Short pin 30 Yes Next on fuel pump relay and pin 87 to start fuel pump. No 9 Check if fuel pressure is 250—300 kPa. 3 Disconnect fuel pipe. Shut off ignition key. Yes Next After 1 hour, check if pressure in fuel system No Repair fuel sys- can keep 150—200 kPa. tem leak 4 Connect fuel pipe. Use returning fuel blocker to Yes Replace fuel pre- block returning fuel pipe and shut off fuel ssure regulator pressure gauge valve. Shut off ignition key. No Next After 1 hour, check if pressure in fuel system can keep 150—200 kPa. 5 Check if injector and fuel pipe leaks fuel. Yes Replace injector and oilpipe
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Chery QQ Maintenance Manual 372 EFI System
No Next 6 Pull out water temperature sensor connector and Yes Check coolant run engine. Check if engine can start. temperature and circuit No Next 7 Connect adaptor between ECU and harness. Yes Next Check if voltage exisit on pin 1,2. Check if the No Repair or replace positive source on above pins and ground wires harness of pin 22,44,63 on ECU are normal. 8 Replace fuel and heat start engine again. Check Yes Harness if engine can start. No Replace ECU 9 Check if fuel pipe blocked or bend, or if fuel Yes Next pump regulator can work normally. No Repair or replace 10 Use multimeter tocheck if voltages between two Yes Next ends of fuel pump inserter exists. No Repair or replace fuel pump relay and leading line 11 Check if fuel pump resistance is correct. Yes Next No Replace fuel pump 12 Yes Replace fuel Check if fuel pump blocked. pump No Replace ECU
4）RPM is normal but difficult in starting No. Operation steps Test results Next step 1 Turn on ignition key. Use tester to check if Yes Eliminate malfunction information record exists. malfunction No Next 2 Check if air filter is through. Yes Next No Replace 3 Check if MAP pressure is 35—65 kPa in idle Yes Next after start. No Eliminate intake system leak 4 Step down throttle slightly and check engine can Yes Replace or check start easily. throttle valve and idle pass 5 Connect fuel pressure gauge valve. Short pin 30 Yes Next on fuel pump relay and pin 87 to start fuel pump. No 9 Check if fuel pressure is 250—300 kPa. 6 Yes 8
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Chery QQ Maintenance Manual 372 EFI System
Use special connector to supply 12 V voltage No Next from battery to injector and check if injector works normally. 7 Re-check if injector can inject fuel after Yes Next cleaning. No Replace injector 8 Replace fuel. Check If fuel deteriorate or Yes Replace fuel containing water. No 14 9 Check if fuel pressure below 250kPa. Yes Next No 13 10 Shut off fuel gauge valve. Connect ignition key Yes Next again to run fuel pump for 3 seconds. Check if No 12 fuel pressure can be set up. 11 Open fuel gauge valve, use return fuel blocker to Yes Replace fuel clamp fuel pipe for no returning fuel. Check if pressure fuel pressure can be set up soon. regulator No Repair and replace injector or fuel pipe 12 Connect fuel pessure gauge valve. Short pin 30 Yes Repair and on fuel pump relay and pin 87 to start fuel pump. replace fuel pipe Check if fuel pressure is 250—300 kPa No Replace fuel pump 13 Check returning fuel pipe is blocked or bend. Yes Repair or replace returning fuel pipe No Replace fuel prassure regulator 14 Pull out idle actuator connector before coolant Yes Next temperature reaches 35 C and check if engine No Repair or replace speed is dropping. idle actuator 15 Yes Next Turn on ignition key. Check voltages on No Check harness or following pins are normal: 12 V for pin 27 and connector zreo for pin 14 and 19. 16 Run engine in idle. When coolant temperature Yes Next reaches normal, ground pin 51 and check if No Adjust ignition ignition advance angle is 6.75 crank angle. advance angle
17 Check if cylinder compressed pressure is Yes Next normal. No Trouble shooting 18 Yes Repair or replace
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Chery QQ Maintenance Manual 372 EFI System
Check if MAP and IAT blocks. No Next 19 Check if coolant temperature sensor is normal. Yes Replace ECU No Repair or replace
5）Cold start difficult No. Operation steps Check results Next step 1 Turn on ignition key. Use tester to check if Yes Eliminate malfunction information record exists. malfunction No Next 2 Use multimeter to check if coolant temperature Yes Next sensor is normal. Or link 1.5k resistors between No Replace sensor pin 45 and pin 30 on ECU to relace coolant
temperature sensor for starting engine. If engine can start, coolant temperature sensor is normal. 3 Turn on ignition key. Check if voltages on Yes Next following pins are normal: 12 V for pin 27 and No Check harness zreo for pin 14 and 19. and connector 4 Yes Next Check if air filter is through. No Replace 5 Check if MAP pressure is 35—65 kPa in idle Yes Next after start. No Eliminate intake system malfunction 6 Step down throttle slightly and check engine Yes Check throttle can start easily. and idle pass No Next 7 Pull out idle actuator connector before coolant Yes Next temperature reaches 35 C and check if engine No Repair or replace speed is dropping. idle actuator 8 Connect fuel pressure gauge valve. Ground pin Yes Next 86 on fuel pump relay. Turn on ignition key to No 12 run fuel pump relay anfd fuel pump to check if fuel pressure is 250—300kPa. 9 Use special connector to supply 12 V voltages Yes 11 from battery to injector and check if injector No Next works normally. 10 Re-check if injector can inject fuel after Yes Next cleaning. No Replace injector 11 Check If fuel deteriorate or containing water. Yes Replace fuel No 17
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Chery QQ Maintenance Manual 372 EFI System
12 Check if fuel pressure below 250kPa. Yes Next No 16 13 Shut off fuel gauge valve. Connect ignition key Yes Next again to run fuel pump for 3 seconds. Check if No 15 fuel pressure can be set up. 14 Open fuel gauge valve, use return fuel blocker Yes Replace fuel to clamp fuel pipe for no returning fuel. Check pressure if fuel pressure can be set up soon. regulator No Repair or replace injector and fuel pipe 15 Check if fuel pipe is leaked or blocked. Yes Repair or replace intake fuel pipe No Replace fuel pump 16 Check returning fuel pipe is blocked or bend. Yes Repair or replace returning fuel pipe No Replace fuel pressure regulator 17 Check if cylinder compressed pressure is Yes Next normal. No Troble shooting 18 Check if intake air system is leak. Yes Repair No Next 19 Check if MAP and IAT blocks. Yes Repair or replace No Replace ECU
6）Unstable idle at any situation 1 Turn on ignition key. Use diagnostic equipment Yes Eliminate to check if malfunction information record exists. malfunction No Next 2 Check if EWD3 idle actuator or step motor Yes Repair or replace actuator blocked. idle actuator No Next 3 Turn on ignition key. Connect adaptor between Yes Check harness and ECU and harness. Check if voltages on pin 31,56 connector ( output signal for IAT and ECT), pin 19,20,35,36 (output signal for stepmotor) and pin19, 35 (for No Next EWD3) are normal. 4 Yes 8
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Chery QQ Maintenance Manual 372 EFI System
Run engine in idle. Shut off each cylinder one by No Next one and check if engine speed is dropping or fluctuates. 5 Check if each injector works normally. Yes Next No Check injector and harness 6 Check if the resistance of high voltage wire is Yes Next normal No Replace 7 Check if any ablation damage or crack on No Replace distributor cove and distributor. No Next 8 Check if spark plug is normal. Yes Next No Replace spark plug 9 Connect fuel pressure gauge valve. Short pin 30 Yes Next and pin 87 of fuel pump relay to start fuel pump. Check if fuel pressure is 250—300 kPa. No 13 10 Use special connector to supply 12 V voltages Yes 12 from battery to injector and check if injector No Next works normally. 11 Re-check if injector can inject fuel after cleaning. Yes Next
No Replace injector 12 Replace fuel. Check If fuel deteriorates or Yes Replace fuel containing water. No 18 13 Check if fuel pressure below 300kPa. Yes Next No 17 14 Shut off fuel gauge valve. Connect ignition key Yes Next again to run fuel pump for 3 seconds. Check if No 16 fuel pressure can be set up. 15 Open fuel gauge valve, use return fuel blocker Yes Replace fuel to clamp fuel pipe for no returning fuel. Check if pressure regulator fuel pressure can be set up soon. No Repair and replace injector or fuel pipe 16 Check if fuel pipe is leaked or blocked. Yes Repair or replace fuel pipe No Replace fuel pump 17 Check returning fuel pipe is blocked or bend. Yes Repair or replace returning fuel pipe No Replace fuel pressure regulator
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Chery QQ Maintenance Manual 372 EFI System
18 Check if sensor holes on MAP and IAT block. Yes Cleaning No Next 19 Run engine in idle. After coolant temperature Yes Next reaches actuating temperature for closed loop No Check oxygen control, check if oxygen sensor works normally. sensor and harness Chec if intake air system leaks. Yes Eliminate leak 20 No Next
21 Check if cylinder pressure is normal. Yes Next No Trouble shooting
7） Unstable idle at heat engine 1 Turn on ignition key. Use diagnostic equipment Yes Eliminate to check if malfunction information record exists. malfunction No Next 2 Check if air filter is through. Yes Next No Replace 3 Check if MAP pressure is 35—65 kPa at idle in Yes Next heating engine process. No Eliminate intake system malfunction 4 Shut off engine ,turn on ignition key. Connect Yes Next adaptor between ECU and harness. Check if voltages on pin 31,56 ( output signal for IAT and No Check ECT) is normal. 5 Pull out idle actuator connector before heat Yes Next engine finish and check if engine speed is normal No Replace idle actuator 6 Check if coolant temperatuer sensor is normal Yes Next No Replace
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Chery QQ Maintenance Manual 372 EFI System
8）Unstable idel after heat engine 1 Turn on ignition key.Use diagnostic equipment to Yes Eliminate check if malfunction information record exists malfunction No Next 2 Turn on ignition key.Connect adaptor between Yes Next ECU and harness. Check if voltages on pin No Repair or replace 60,56.31,43( output signal for MAP,IAT,ECT harness and oxygen sensor)and pin 19,20,35,36 (output to
idle actuator)are normal 3 Shout off engine .Check if air filter is through Yes Next No Replace 4 Check if MAP pressure is 35—65 kPa at idle Yes Next No Eliminate intake system leak 5 Connect fuel pressure gauge valve. Short pin 30 Yes Next and pin 87 of fuel pump relay to start fuel pump. No 9 Check if fuel pressure is 250—300 kPa. 6 Use special connector to supply 12 V voltages Yes 8 from battery to injector and check if injector No Next works normally. 7 Re-check if injector can inject fuel after cleaning. Yes Replace No Replace injector 8 Check if fuel is deterirate or containing water Yes Replace fuel No 14 9 Check if fuel pressure blowe 250kpa Yes Next No 13 10 Shut off fuel gauge valve. Connect ignition key Yes Next again to run fuel pump for 3 seconds. Check if No 12 fuel pressure can be set up. 11 Open fuel gauge valve, use return fuel blocker to Yes Replace fuel clamp fuel pipe for no returning fuel. Check if pressure regulator fuel pressure can be set up soon. No Repair and replace injector or fuel pipe 12 Check if fuel inlet is leak or block Yes Repair or replace fuel inlet No Replace fuel pump 13 Check if return fuel pipe is block or bend Yes Repair or replace return fuel pipe No Replace fuel pressure regulator
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Chery QQ Maintenance Manual 372 EFI System
14 Pull out coolant temperature sensor and check if Yes Replace coolant engine is normal temperature sensor No Next 15 Check if cylinder compression pressure of engine Yes Next is normal No Trouble shooting 16 Check if the resistance of high voltage wire is Yes Next normal (about 16k/ m. For exact data, please No Replace touch manufacture).。 17 Check if any ablation damage or crack on Yes Replace distributor cover and distributor No Next 18 Check if spark plug is normal Yes Replace ECU No Replace spark plug
9）Unstable idel or switch off
1 Turn on ignition key.Use diagnostic equipment to Yes Eliminate check if malfunction information record exists malfunction No Next 2 Turn on A/C switch. Turn on ignition Yes Next key.Connect adaptor between ECU and harness. No Repair A/C circuit Check if pin 50 and 58(A/C switch) have signal input 3 Check if A/C system pressure,magnetic clutch of Yes Next compressor and A/C pump are normal No Repair or replace 4 Turn on ignition key. Check if voltage on Yes Next pin19,20,35,36(output to idle actuator)are normal No Check control circuit 5 Remove stepmotor and check if stepmotor is Yes Repair or replace jamming or does not work flexibly stepmotor No Next 6 Turn engine and open A/C .Check if idle actuator Yes Replace ECU is normal No Replace idle actuator
Chery Automobile Co., Ltd
Chery QQ Maintenance Manual 372 EFI System
10）Preiodicity unstable(ECU needs self-study again) 1 Turn on ignition key.Use diagnostic equipment to Yes Eliminate check if malfunction information record exists malfunction No Next 2 Check if air filter is through。 Yes Next No Replace 3 Check if intake pressure is 35—65 kPa in idle Yes Next No Repair 4 Run engine in idle. Shut off each cylinder one by Yes 7 one and check if engine speed is dropping or No Next fluctuates. 5 Turn on ignition key.Connect adaptor between ECU Yes Next and harness. Check if voltages on pin 48,60,45,28( output signal for MAP,IAT,ECT and oxygen sensor),1,2(ground),22(ignition switch)and pin 19,20,35,36(output to idle actuator)are normal No Rpair or replace harness
6 Run engine in idle. After coolant temperature Yes Next reaches normal,check if ignition advance angle is No Adjust ignition normal advance angle
7 Check if sensor holes on MAP and IAT block. Yes Cleaning No Next 8 Check if fuel is deterirate or containing water Yes Replace fuel No Next 9 Use special connector to supply 12 V voltages from Yes Next battery to injector and check if injector works No Repair harness normally. and injector 10 Check if the resistance of high voltage wire is Yes Next normal No Replace 11 Check if any ablation damage or crack on Yes Replace distributor cover and distributor No Next
12 Check if spark plug is normal Yes Replace ECU No Replace spark plug
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Chery QQ Maintenance Manual 372 EFI System
11）Idle is too high (ECU needs self-study again) 1 Turn on ignition key.Use diagnostic equipment to Yes Eliminate check if malfunction information record exists。 malfunction No Next 2 Check if throttle pedal bracing wire is blocked or Yes Adjust or too tight replace No Next 3 Check if canistor control valve,fuel pressure Yes Repair or regulator,PVC vacuum pipe and vacuum replace power-assisted hose of braking system are good No Next 4 Step down brake pedal and check if idle is too high Yes Next while engine idle running and in neutral. No 6 5 Clamp vacuum power-assisted hose and check if Yes Repair or idle is normal replace vacuum actuator No Next 6 Clamp PVC vacuum hose and check if idle is Yes Replace PVC normal No Next 7 Clamp canistor control valve hose and check if idle Yes Replace canistor is normal control valve No Next 8 Check if idle actuator is not flexibly or blocked Yes Repair or replace No Next 9 Check if intake pipe have leak Yes Repair or replace No Next 10 Check if sealing washer of injector is good Yes Next No Replace sealing washer 11 Check if MAP and IAT are good Yes Replace ECU No Replace sensor
12）Speed of engine is low or switch off while speeding up 1 Turn on ignition key.Use diagnostic equipment to Yes Eliminate check if malfunction information record exists。 malfunction No Next z2 Check if air filter is through Yes Next No Replace 3 Check if speed is narmal at idle Yes Next No Next
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Chery QQ Maintenance Manual 372 EFI System
4 Check if intake pressure is 35—65 kPa in idle Yes Next No Repair 5 Run engine in idle. After coolant temperature Yes Next reaches normal, check if ignition advance angle is No Adjust ignition normal advance angle 6 Connect fuel pessure gauge valve. Short pin 30 on Yes Next fuel pump relay and pin 87 to start fuel pump. No 10 Check if fuel pressure is 250—300 kPa 7 Use special connector to supply 12 V voltages Yes 9 from battery to injector and check if injector works No Next normally. 8 Re-check if injector can inject fuel after cleaning. Yes Next No Replace injector 9 Check if fuel is deterirate or containing water Yes Replace fuel 。 No 15 10 Check if fuel pressure below 250kPa. Yes Next No 14 11 Shut off fuel gauge valve. Connect ignition key Yes Next again to run fuel pump for 3 seconds. Check if fuel No 13 pressure can be set up. 12 Open fuel gauge valve, use return fuel blocker to Yes Replace fuel pressure clamp fuel pipe for no returning fuel. Check if fuel regulator pressure can be set up soon。 No Replace and repair injector or fuel pipe 13 Check if fuel pipe is leaked or blocked. Yes Repair or replace fuel inlet No Replace fuel pump 14 Yes Repair or replace Check returning fuel pipe is blocked or bend. returning fuel pipe No Replace fuel pressure regulator 15 Turn on ignition key. Connect adaptor between Yes Next ECU and harness. Check if voltages on pin 32( output signal for TPS) ,pin 38 (ground No Repair or replace connection)and pin 45( for 4.5-5V power of harness sensor) are normal. 16 Check if ignition coil,distrbutor,high voltage wire Yes Replace ECU and spark plug are normal No Repair or replace relate unit
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Chery QQ Maintenance Manual 372 EFI System
13）Speeding up is slow 1 Turn on ignition key.Use diagnostic equipment to Yes Eliminate malfunction check if malfunction information record exists No Next 2 Shout off engine .Check if air filter is through Yes Next No Replace 3 Check if speed is narmal in idle Yes Next No Refer to trouble shooting of idle system 4 Check if intake pressure is 35—65 kPa in idle Yes Next No Repair 5 Turn on ignition key. Connect adaptor between Yes Next ECU and harness. Check if voltages on pin No Repair or replace 32( output signal for TPS) ,pin38 (ground connection)and pin 45( 4.5-5V power for sensor) are normal. 6 Run engine in idle. After coolant temperature Yes Next reaches normal, check if ignition advance angle No Adjust ignition advance is normal angle
7 Connect fuel pessure gauge valve. Short pin 30 Yes Next on fuel pump relay and pin 87 to start fuel pump. No 11 Check if fuel pressure is 250—300 kPa 8 Use special connector to supply 12 V voltages Yes 10 from battery to injector and check if injector No Next works normally. 9 Re-check if injector can inject fuel after cleaning. Yes Next No Replace injector 10 Check if fuel is deterirate or containing water Yes Replace fuel No 16 11 Check if fuel pressure below 250kPa. Yes Next No 15 12 Shut off fuel gauge valve. Connect ignition key Yes Next again to run fuel pump for 3 seconds. Check if No 14 fuel pressure can be set up. 13 Open fuel gauge valve, use return fuel blocker Yes Replace pressure to clamp fuel pipe for no returning fuel. Check if regulator fuel pressure can be set up soon No Repair and replace injector or fuel pipe 14 Check if fuel pipe is leaked or blocked. Yes Repair or replace fuel pipe No Replace fuel pump
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Chery QQ Maintenance Manual 372 EFI System
15 Check returning fuel pipe is blocked or bend. Yes Repair or replace fuel pipe No Replace pressure regulator 16 Check if exhaust system and TWC is blocked Yes Replace or cleaning No Replace ECU
14）Poor performance of acceteration and power lessness 1 Check if exist malfunction as following: clutch Yes Repair slipping,air pressure of tire is low,braking No Next drag,size of tire and four-wheeled alignment are miscorrect 2 Check if throttle can full-open Yes Next No Rpair or replace throttle 3 Turn on ignition key.Use diagnostic equipment Yes Eliminate malfunction to check if malfunction information record No Next exists。 4 Run engine in idle. After coolant temperature Yes Next reaches normal, groun pin 51 on ECU and check if ignition advance angle is 6.75 crank No Adjust ignition advance angle. angle
5 Turn on ignition key.Connect adaptor between Yes Next ECU and harness. Check if voltages on pin 48,60,45,28( output signal for MAP,IAT,ECT and oxygen sensor),1,2(ground),22(ignition switch)and pin 19,20,35,36(output to idle No Repair or replace actuator)are normal harness
6 Check if intake pressure is 35—65 kPa in idle Yes Next after start No Repair 7 Connect fuel pessure gauge valve. Short pin 30 Yes Next on fuel pump relay and pin 87 to start fuel No 11 pump. Check if fuel pressure is 250—300 kPa 8 Use special connector to supply 12 V voltages Yes 10 from battery to injector and check if injector No Next works normally. 9 Re-check if injector can inject fuel after Yes Next cleaning. No Replace injector 10 Check if fuel is deterirate or containing water Yes Replace fuel No 16 11 Check if fuel pressure below 250kPa. Yes Next No 15
Chery Automobile Co., Ltd
Chery QQ Maintenance Manual 372 EFI System
12 Shut off fuel gauge valve. Connect ignition key Yes Next again to run fuel pump for 3 seconds. Check if No 14 fuel pressure can be set up. 13 Open fuel gauge valve, use return fuel Yes Replace pressure blocker to clamp fuel pipe for no returning fuel. regulator Check if fuel pressure can be set up soon。 No Repair and replace injector or fuel pipe 14 Check if fuel pipe is leaked or blocked. Yes Repair or replace fuel inlet No Replace fuel pump 15 Check returning fuel pipe is blocked or bend Yes Repair or replace returning fuel pipe No Replace pressure regulator 16 Check if the date of MAP or IAT are normal。 Yes Next No Replace sensor 17 Check if ignition coil,distrbutor,high voltage Yes Next wire and spark plug are normal No Replace or adjust 18 Check if A/C system is malfunction. Yes Check A/C system No Replace ECU
15）A/C system malfunction 1 Check if there is full coolant and check if A/C Yes Next belt,A/C clutch ,pressure switch are narmal No Eliminate malfunction 2 Turn on A/C switch in engine idle.Check if A/C Yes Eliminate thermistor is malfunction malfunction No Next 3 Turn on A/C switch. Connect adaptor between ECU Yes Next and harness.Check if output signal for ECU pin 50 No Check harness and 58(A/C switch) is normal 4 If the vehicle is low-level contro, check if A/C can Yes Replace bulb or working when turn off A/C. repair harness No Next 5 Check if output low-level for ECU pin 68(connect Yes Repair A/C earthing terminal of A/C relay pull-in coil) relay and harness No Replace ECU
Chery Automobile Co., Ltd
Chery QQ Maintenance Manual 372 EFI System
8. Precaution for service 1) Precaution for service EFI (1) Controler removal request Remove controller before welding or painting; Turn off ignition switch when removing controller to void gamage; Don’t remove power wires from battery when engine running or electric appliance is in using; Don’t start engine with high current; Note that the ambient temperature of controller could not exceed 80Cº (2) Clean request: Please observe following regulations: Put removed parts on clean place and cover them with suitable cloth. Only allowed to pull out ot insert each harness or tester harness after ignition switch turns off. Make sure the correction for connecting wires when measuring voltage or ground for electronic control system; Removing power wires from battery or pulling out controller connector will cause losing the information for diagnosis and self-study stored in memory (3) Precaution for fuel system service When removing or installing fuel pump in fully or partial fully fuel tank, pay close attention to: Mounting equipment that could absorb leaked fuel on tank outlet before operation; Avoid skin touch with fuel directly; Cover or block out the opened parts if not be used at once; Take out parts only before installing. Don’t use the parts witout pakage; Don’t damage o-ring during installing injector. Smear a little lubricant on o-ring for beteer fitting; Don’t use compressed air or move vehicle when opening system.
2) Safety precaution In order to avoid personal hurt or damage injector and ignition unit, pay close attentionto: (1) Don’t touch otr pull out ignition harness if engine is running or starting; (2) Pull bout harness connector if engine is started by starter motor (for example in the situation of checking compressed air).
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