Chery A21 2005, Service Manual, Page: 324 / 475

CHERY
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A21 SERVICE MANUAL ENGINE EFI SYSTEM
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CONTENT
1. NOTICE TO THE EFI SYSTEM SERVICE .........................................................................................3
1.1. GENERAL SERVICE ...........................................................................................................................3
1.2. NOTICE DURING THE SERVICE .............................................................................................3
1.3. SERVICE TOOLS .........................................................................................................................4
1.4. EXPLANATIONS OF THE ABBREVIATION IN THE MANUAL .........................................6
2. ME7.9.7 SYSTEM INTRODUCTION ....................................................................................................6
2.1. SYSTEM BASIC PRINCIPLE .....................................................................................................6
2.1.1 SYSTEM GENERAL INTRODUCTION: ME7.9.7-MOTRONIC EMS .......................6
2.2. CONTROL SIGNAL: ME7.9.7 SYSTEM INPUT/OUTPUT SIGNAL....................................8
2.3. INTRODUCTION OF SYSTEM MALFUNCTION DIAGNOSIS FUNCTION.....................9
2.3.1. MALFUNCTION INFORMATION RECORD ...............................................................9
2.3.2, CONTROL STRATEGY OF FAILURE LAMP ..............................................................9
2.3.3, DIAGNOSIS METER CONNECTION..........................................................................10
2.3.4, READ MALFUNCTION INFORMATION BY WINK CODE....................................10
3. WORKING PRINCIPLE AND CHARACTER OF EFI SYSTEM ELEMENT ...............................10
3.1 ELECTRONIC CONTROL UNIT - ECU ..................................................................................10
3.2 COOLANT TEMPERATURE SENSOR ....................................................................................14
3.3 KNOCK SENSOR ........................................................................................................................15
3.4 OXYGEN SENSOR ......................................................................................................................16
3.5 SPEED SENSOR (CRANKCASE POSITIONING SENSOR) .................................................17
3.6 PHASE SENSOR (CAM SHAFT POSITIONING SENSOR) ..................................................19
3.7 ELECTRIC FUEL PUMP ...........................................................................................................20
3.8 ELECTROMAGNETIC INJECTOR .........................................................................................21
3.9 AIR FLOW SENSOR ...................................................................................................................22
3.10 DOUBLE SPARK IGNITION COIL ........................................................................................23
3.11 CARBON CANISTER SOLENOID VALVE ............................................................................25
3.12 FUEL PRESSURE REGULATOR ............................................................................................26
3.13 ELECTRONIC THROTTLE VALVE AND ACCELERATOR ..............................................27
3.14 FAN CONTROL .........................................................................................................................28
3.15 AIR CONDITIONER CONTROL ............................................................................................29
4 ME7 SYSTEM TEST AND REPAIR ACCORDING TO TDC ...........................................................30
4.1 ENGINE DTC (DIAGNOSTIC TROUBLE CODE) LIST .......................................................30
4.2 DIAGNOSIS FLOW WHEN THERE IS DIFFERENT DTC ..................................................32
5. TYPICAL FAILURE AND ITS DIAGNOSIS FLOW .........................................................................52
5.1 EXPLANATION ...........................................................................................................................52
5.2 TYPICAL FAILURE DIAGNOSIS FLOW ...............................................................................53
1. The engine does not rotate or rotate slowly when it is started ............................................53
2. The engine can draw rotating but can not start successfully when it is started. ...............54
3. It is hard to start the heating car. ..........................................................................................55
4. It
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s hard to start the cold car. .................................................................................................56
5. Normal engine speed but hard to start at any time. ............................................................57
6. Regular starts but the idle speed is not steady at any time. ................................................58
7. Regular starts but the idle speed is not steady during engine heating. ..............................59
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