JAC S2. Engine. Service Manual — part 18

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Ignition switch is ON (does not start), MIL keeps lightening;

After 3s starting the engine, if there is no fault request to light MIL in fault storage, MIL will die out.

If there is fault requests to light MIL in fault storage or from outside of ECM, MIL will be lighted up.

When there is request from outside of ECM or get fire or from fault storage, MIL will glitter with 1HZ

frequency.

4. Trouble shooting steps:

1). Connect the diagnostic tester with diagnostic connectors, then turn on the tester.

2). 。 Turn on the ignition switch.

3). Read relative information (fault code, freeze frame); consult the service book to confirm faulted

components and type; make service proposal according to information and experience.

4). Shoot the trouble.

5). Eliminate fault storage; appropriately drive the vehicle under the condition which meets corresponding
fault diagnosis; read fault info to make sure the fault is solved.

5. Instruction of detection and diagnosis equipment

Maintenance mode of electronic control system is quite different with mechanical system; it relies on electric

equipment and use OBD system to do trouble shooting. Normal equipments used in electronic control system

include auto computer detector, digital multimeter and etc.

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You can build connection with ECM by connect the computer detector with diagnostic socket, and visit

relative fault diagnosis data in ECM storage, including fault code and data flow, in order to know the monitoring

results and system working situation which will provide evidence for trouble shooting. Besides, it also can do

movement test.

(1)Read and eliminate fault code

You can easily read fault code stored in ECM by connect the computer detector with diagnostic socket. The

computer detector will display the code and its meaning on screen. By reading the code, serviceman can handle

faults like short circuit and open circuit of most sensors and controlling circuits in electronic control system.

(2)Read data flow

Connect the computer detector and electronic control system to read ECM working situation and transient data

of input, output signal (signal of sensors, calculation results of ECM, controlling modes, control signal transmitted

to actuators and etc.). Serviceman can judge if the system works normally according to changes of different datas,

or compare the signal value under specified conditions to standard value, in order to correctly judge the type

and position of fault.

(3)Movement test

Movement test: Computer detector gives commands to ECM to drive or stop some work of actuators, for

detecting actuator’s working condition and finding the faulted actuators or controlling circuits.

6. ECU common fault code and instruction

Lighting principles of MIL and SVS: different set of fault types will have different lighting timing and method. And

the fault types can be classified as A, B, C, D, E and Z by degree of influence on exhaust emission, the definition

and lightening rules are as followed:

MIL (relative components of exhaust control) activation rules:

A: as long as the fault occurs, system will light up MIL and record fault code

B: only when the fault occurred in consecutive two emission monitoring

process, system will light up MIL and record fault code

E: only when the fault occurred in consecutive three emission monitoring

process, system will light up MIL and record fault code

Notice A emission monitoring process is a working cycle that all OBD functional tests can be done. It is

also based on EⅢ emission test program.

SVS (relative components of exhaust control) activation rules:

C: record the fault code when it occurred, and light up SVS

indicator light, but not the MIL.

Z: fault diagnosis system didn’t do any analysis to this type of

faults

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(II)Diagnostic analysis table

No.

Fault

Analysis of reason

How to solve

1

engine
cannot start

no oil in tank

add some

oil pump does not work

check the circuit; change the oil pump if necessary

oil injector dose not work

check the circuit; change the oil pump if necessary

ignition system does not work

check the ignition system

oil pressure is too low

check the oil pipes and oil pump

ignition angle of advance is wrong Check VVT and OCV to see if they need any

change

high pressure spark is too weak

change the sparking plug

leakage of oil injector

change the oil injector

ECM does not work

change the ECM

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No. Fault

Analysis of reason

How to solve

2

Engine

is

hard to start

oil pressure is too low

check the oil pipes and oil pump

water temperature sensor has fault change a sensor

leakage of oil injector

change the oil injector

oil injector is plugged

clean the oil injector, or change it if necessary

ignition timing is abnormal

check the OCV; change it if necessary

bad performance of ignition plug
and ignition coil

change the ignition plug and ignition coil

harness of power supply has fault chaeck the harness

pressure of cylinder is too low

check the pressure of cylinder, if the pressure is
lower than 1.1Mpa, that means there is fault
and you should disassemble and check the
engine

ECM does not work

change the ECM

3

idle speed is
not stable

oil pressure is too low

check the oil pressure, if it’s too low, please
check if the oil pump works normally or the oil
filter be plugged

bad atomization, leakage or block
of oil injector

change the oil injector

bad performance of ignition plug check if the ignition plug is too old or has

serious carbon deposition or the clearance is
too big; and change it if necessary

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inlet air temperature pressure
sensor has fault

change the inlet air temperature pressure
sensor

canister purge solenoid works in
idle speed

check the canister purge solenoid if necessary

air pressure is too low in cylinder
or the difference of pressure in
each cylinder is too big

check the pressure of cylinder, if the pressure is
lower than 1.1Mpa, that means there is fault
and you should disassemble and check the
engine

4

Rotate
speed of idle
speed is too
high

throttle fault

change the throttle

leakage of air inlet pipe

tightening some parts

accelerator pedal fault

change the accelerator pedal

water temperature sensor fault

change the water temperature sensor

canister purge solenoid fault

change the canister purge solenoid

5

怠 速 转 速 波

动过 大

bad atomization or block of oil
injector

change the oil injector

bad performance of ignition plug change the ignition plug

signal of water temperature sensor
is wrong

change the water temperature sensor

oxygen sensor fault

change the oxygen sensor

electronic throttle or control circuit
fault

change the electronic throttle

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No. Fault

Analysis of reason

How to solve

6

vehicle will
easily be shut
down in idle
speed

ignition system does not work
normally

读取， check related parts according to fault

codes

oil system does not work normally check oil pressure, if it is

abnormal, please check related
parts of oil system

electronic throttle fault

change the electronic throttle

bad contact of harness connector
in controlling system

tightening the harness connector
of controlling sytem

7

动力不足 lack of
power

block of air filter

clean the air filter

drop at joints of air inlet pipes

solve the drop problem

electronic throttle fault

change the electronic throttle

oil pressure is too low

check the oil pipes and oil pump;
change it if necessary

bad atomization or block of oil
injector

check oil injector to see if there
are faults like serious carbon
deposition; change it if necessary

water temperature sensor fault

change the water temperature
sensor

fault of inlet air temperature
pressure sensor

change the inlet air temperature
pressure sensor

ignition timing is wrong

check OCV; change it if necessary

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pressure in cylinder is abnormal

check the pressure of cylinder, if
the pressure is lower than 1.1Mpa,
that means there is fault and you
should disassemble and check the
engine

(III)Fault-diagnosis flow chart

Begin to check

1. Get the information

about the fault and

ask the customer for

2. Check and print

DTC; freeze frame data

and check related

3. Confirm the fault and

try to make the

diagnosis based on

4Customer described

the fault; does the

instrument showed

Ye

No

4. Confirm the fault and

try to make the

diagnosis based on

Yes

No

Customer didn’t describe the fault, but

the instrument showed DTC

5. Carry out

steps DTC

Use fault

diagnostic unit

6. Do basic

checks

9. Check fault system

through fault symptom

7. Run the fault-

diagnosis checking

No

Yes

10. Check the

faulted

components based

Find the faulted

components or not

No

No

Beyond the

technical scope or

8. Check the

faulted

Yes

11. Repair or change the

Yes

Abnormal (the fault

still exists)

Abnormal (the fault

still exists)

12. Final check

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(IV)Fault Code Table

Overview

1、 Instruction

1) Unless it is confirmed to be steady state fault, the following service can be started, or it may cause
false diagnosis.

2) The ‘multimeter’ mentioned in the following means digital multimeter. DO NOT use pointer
multimeter to check circuits of electronic control system.

3) If you are checking a vehicle with anti-theft system, and have to change ECM in ‘next steps’, please
pay attention to do matching work after the change.

4) If the fault code says the circuit has too-low voltage, that may implies that there is short circuit or open

circuit in this circuit; if the fault code says the circuit has too-high voltage, that may implies that there is

short circuit to power in this circuit; if the fault code says it’s circuit fault, that may implies that there is

open circuit or multi-fault in this circuit.

2、Diagnosis support

1) If the fault code cannot be eliminated, that is steady state fault; if it is occational fault, you shoud
mainly check whether the connectors are loosen up.

2) During the service, please also pay attention to the Influence of vehicle maintenance condition,
cylinder pressure and mechanical ignition timing on the system.

3、Fault Code Diagnosis

ECM pins mentioned in the following should be subjected to practical wiring diagram.

4、MT22.1 ECM controlling system common fault code sheet

No. Fault code

Fault code information

Type of
fault

1

P 0012

big phase error of air inlet VCP camshaft

E

2

P 0016

learning deviation of air inlet VCP cam wheel is out of range

A

3

P 0026

vise of air inlet VCP hydraulic control valve

E

4

P 0031

front oxygen sensor heater short-circuit to low voltage

A

5

P 0032

front oxygen sensor heater short-circuit to high voltage

A

6

P 0037

rear oxygen sensor heater short-circuit to low voltage

A

7

P 0038

rear oxygen sensor heater short-circuit to high voltage

A

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8

P 0068

electronic throttle valve air mass flow fault

A

9

P 0076

low voltage or open circuit of air inlet VCP hydraulic control valve coil

A

1
0

P 0077

high voltage of air inlet VCP hydraulic control valve coil

A

1
1

P 0105

signal vise of air inlet pressure sensor

E

1
2

P 0106

inlet air pressure/accelerator pedal position

E

1
3

P 0107

low voltage circuit or open circuit of inlet air pressure sensor

A

1
4

P 0108

high voltage circuit of inlet air pressure sensor

A

1
5

P 0112

ow voltagecircuit l of inlet air temperature sensor

E

1
6

P 0113

high voltage or open circuit of inlet air temperature sensor

E

1
7

P 0117

low voltage circuit of coolant temperature sensor

E

1
8

P 0118

high voltage or open circuit of coolant temperature sensor

E

1
9

P 0122

low voltage circuit of electronic throttle valve position sensor 1#

A

2
0

P 0123

high voltage circuit of electronic throttle valve position sensor 1#

A

2
1

P 0131

front oxygen sensor short-circuit to low voltage

E

2
2

P 0132

front oxygen sensor short-circuit to high voltage

E

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No.

Fault code

Fault code information

Type of
fault

23

P 0133

too-low reacting of front oxygen sensor

E

24

P 0134

short-circuit of front oxygen sensor

A

25

P 0137

rear oxygen sensor short-circuit to low voltage

E

26

P 0138

rear oxygen sensor short-circuit to high voltage

E

27

P 0140

short-circuit of rear oxygen sensor

E

28

P 0171

too lean of oil system under non-idle speed

E

29

P 0172

too rich of oil system under non-idle speed

E

30

P 0222

low voltage circuit of electronic throttle valve position sensor 1#

A

31

P 0223

high voltage circuit of electronic throttle valve position sensor 1#

A

32

P 0230

oil pump relay fault

A

33

P 0261

low voltage circuit fault of 1

st

cylinder nozzle

A

34

P 0262

high voltage circuit fault of 1

st

cylinder nozzle

A

35

P 0264

low voltage circuit fault of 2

nd

cylinder nozzle

A

36

P 0265

high voltage circuit fault of 2

nd

cylinder nozzle

A

37

P 0267

low voltage circuit fault of 3

rd

cylinder nozzle

A

38

P 0268

high voltage circuit fault of 3

rd

cylinder nozzle

A

39

P 0270

low voltage circuit fault of 4

th

cylinder nozzle

A

40

P 0271

high voltage circuit fault of 4

th

cylinder nozzle

A

41

P 0300

single or multi cylinders are on fire

A/B

42

P 0324

block control system fault

C

43

P 0325

block sensor fault

C

44

P 0335

no signal of circuit of crankshaft position sensor

A

45

P 0336

signal interference circuit of crankshaft position sensor

E

46

P 0340

no signal of circuit of camshaft position sensor

E

47

P 0341

fault of circuit reasonability of camshaft position sensor

E

48

P 0340

state diagnosis of air inlet VCP camshaft position sensor

A

49

P 0341

diagnosis fault of air inlet VCP target wheel

A

50

P 0351

1

st

cylinder ignition coil fault

A

51

P 0352

2

nd

cylinder ignition coil fault

A

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52

P 0353

3

rd

cylinder ignition coil fault

A

53

P 0354

4

th

cylinder ignition coil fault

A

54

P 0420

low efficiency of catalytic converter

A

55

P 0458

canister purge solenoid short-circuit to low voltage or open circuit

E

56

P 0459

canister purge solenoid short-circuit to high voltage

E

57

P 0480

low-speed fan fault

C

58

P 0481

high-speed fan fault

C

59

P 0502

no signal of speed sensor

E

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No.

Fault code

Fault code information

Type of
fault

60

P 0504

correlative fault of brake switch

C

61

P 0506

idle speed is too low

E

62

P 0507

idle speed is too high

E

63

P 0562

system voltage is too low

C

64

P 0563

system voltage is too high

C

65

P 0571

on-off state of brake light didn’t change while braking

E

66

P 0602

ECM programming error (mismatch of software version)

A

67

P 0606

ECM processor fault

A

68

P 0606

ECM processor fault

A

69

P 0606

ECM processor fault

A

70

P 0606

ECM processor fault

A

71

P 0606

ECM processor fault

A

72

P 060A

ECM processor fault

A

73

P 060A

ECM processor fault

A

74

P 060A

ECM processor fault

A

75

P 0616

low voltage of starter relay

A

76

P 0617

high voltage of starter relay

A

77

P 0633

non-learning fault of burglar alarm

C

78

P 0641

ETC reference voltage A# amplitude fault

A

79

P 0646

short circuit to low voltage or open circuit of AC clutch relay circuit C

80

P 0647

short circuit to high voltage of AC clutch relay circuit

C

81

P 0650

fault indicator light failure

C

82

P 0651

ETC reference voltage B# amplitude fault

A

83

P 0685

main relay fault

A

84

P 0685

main relay fault

A

85

P 0831

signal of clutch switch circuit is often low (short circuit to ground or
open circuit)

C

86

P 0832

signal of clutch switch circuit is often high (short circuit to ground
or open circuit)

C

87

P 1167

front oxygen is too rich during deceleration fuel cutoff

E

88

P 1171

front oxygen is too thin during acceleration enrichment

E

89

P 1336

58 tooth gear error non-learning

A

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90

P 1397

no signal of wheel speed sensor

C

91

P 1516

diagnosis error for ETC drive steady state

A

92

P 2101

diagnosis error for ETC drive second order

A

93

P 2104

forced idle of engine

A

94

P 2105

forced stop of engine

A

95

P 2106

engine performance limitation

A

96

P 2110

engine power management

A

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No.

Fault code

Fault code information

Type of
fault

97

P 2119

electronic throttle valve return fault

C

98

P 2122

low voltage of electronic accelerator pedal position sensor 1#
circuit

A

99

P 2123

high voltage of electronic accelerator pedal position sensor 1#
circuit

A

100

P 2127

low voltage of electronic accelerator pedal position sensor 2#
circuit

A

101

P 2128

high voltage of electronic accelerator pedal position sensor 2#
circuit

A

102

P 2135

correlative fault of electronic throttle valve position sensor 1#, 2#
circuit

E

103

P 2138

correlative fault of electronic accelerator pedal position sensor 1#,
2# circuit

A

104

P 2187

too-thin fuel system under idling condition

E

105

P 2188

too-rich fuel system under idling condition

E

106

P 2A01

slow response of rear oxygen sensor during deceleration fuel cutoff E

107

U 0167

(C167) no response of burglar alarm

C

108

U 0426

(C426) burglar alarm authentication

failure

C

109

B 0010

(8010) fault of crash fuel cutoff rationality

C

Fault Code ：P0012

fault code

P0012

air inlet VCP cam phase is big

setting emergency control scheme

light up fault lamp until it is off

connection terminal

MT22.1

VPC control

normal measurement
signal

variable timing control signal

43

B

0 ～ 1000mV

main relay

\

A

12V

judging criteria

possible fault reason

referenced trouble shooting scheme

engine running fault
lasts for more than 2
seconds

1. poor connecting of connectors

1. connect again

2. open circuit of variable timing control signal 2. repair wiring harness

3. short circuit of variable timing control signal 3. repair wiring harness

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4. circuit fault of main relay

4.

repair wiring harness

5. sensor damage

5. change the sensor

6. timing control signal inputing port fault on
ECM

6. change the ECM

Fault Code :P0026

fault code

P0026

air inlet VCP hudraulic control valve vise

setting emergency control scheme

light up fault lamp until it is off; turn off the air inlet VCP
hudraulic control valve

connection terminal

MT22.1

VPC control

normal measurement
signal

variable timing control signal

\

A

12V

main relay

43

B

0-12V

judging criteria

possible fault reason

referenced trouble shooting scheme

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fault code

P0026

air inlet VCP hudraulic control valve vise

lasts for more than 2
seconds

1. hydraulic control valve drive circuit got
short circuit to system power positive

1. repair wiring harness

2. hudraulic control valve damage

2. change the control valve

3 ECM fault

3. change the ECM

Fault Code P0107

fault code

P0107

open circuit or low voltage of air inlet pressure sensor circuit

setting emergency control scheme

light up fault lamp until it is off; engine is stop: 100kPa; engine is
in idle: ≈ 32kPa
engine is running: manifold pressure changes with the opening of
throttle valve

connection terminal

MT22.1

pressure sensor

normal measurement
signal

5V reference voltage

66

3

5V

manifold pressure signal

54

4

0.5 ～ 4.5V

sensor signal ground

76

1

0V

judging criteria

possible fault reason

referenced trouble shooting scheme

engine is running

without TPS fault

MAP<14.017KPa

RPM<1050rpm

TPS>18.75 % the

fault lasted for

more than 2.5

seconds

1. poor connecting

1. connect it again

2. open circuit of harness pressure signal
circuit

2. repair wiring harness

3. short circuit to ground of harness
pressure signal circuit

3. repair wiring harness

4. open circuit of 5V reference voltage
circuit

4. repair wiring harness

5. open circuit of sensor signal ground
circuit

5. repair wiring harness

6. harness of 5V reference voltage circuit is

in reverse with reference ground wire (this

fault can cause damage of sensor)

6.repair wiring harness

7. sensor damage

7. change the sensor

8. MAP signal inputing port fault on ECM

8. ECM change the ECM

Fault Code :P0108