EF04

EF12

18

05

01

1

2

54

EO01

EO01

A

B

57

VVT1

OCP

EO35

EO35

3

IGN

MAIN

EO35

EO35

EO35

EO35

EO35

MPR

62

22

VBATPROT

VBATPROT

6

B

A

PWR GND EO35

73

CAN HI

CAN HI

CAN LO

CAN LO

EO35

EO35

16

32

VBAT

1

2

4

3

1

FPR

71

EF22

EF06

EO01

72

62

SDATA

IMMORQST

M

Engine Control Module

Main Relay

Evaporative Canister Solenoid

VVT Solenoid

To Ignition Coil

Ignition Relay

Fuel Pump Relay

To Instrument Cluster

Fuel Pump 

Assembly

Anti-theft 

Module

Ignition Switch

FE02-5201b

Engine

Control System JL4G15-D

2-603

EO01

IF

29

23

INJA

INJD

INJB

INJC

65

66

EO01

EO01

EO01

EO01

B

A

C

EO01

EO01

1

17

COILA

COILB

b

EO01

EO01

KNOCK HI

KNOCK LO

12

28

9

27

6

EO01

EO01

EO01

EO01

3

4

1

2

V5REF2

MAP

V5RTN2

MAT

EO01

EO01

29

24

CLT

V5RTN3

3

1

2

1

MP+

ACRQST+

EO35

EO35

EO35

9

65

EO35

51

A/C CLUTCH

A

EO35

EO35

67

66

FANLO

FANHI

1

2

18

BRAKELP

P

Engine Control Module

To Air Conditioning

Pressure Switch

To Brake Light Switch

Engine Coolant Temperature Sensor

Intake Air Pressure 
Temperature Sensor

Knock Sensor

Ignition Coil

Cooling Fan Low Speed Relay

Cooling Fan High 
Speed Relay

Cooling Fan 
Relay

Air Conditioning Compressor Relay

Air Conditioning 
Compressor Clutch

Cylinder No.1 Fuel Injector

Cylinder No.2 Fuel Injector

Cylinder No.3 Fuel Injector

Cylinder No.4 Fuel Injector

Ignition Relay

FE02-5202b

2-604

Control System JL4G15-D

Engine

EO35

13

14

41

14

EO01

D

C

02A HTR

A

B

EO01

10

2

02AHI

02ALO

EO01

D

C

A

B

EO01

EO01

EO01

EO01

EO01

EO01

46

02B HTR

30

02BHI

55

02BLO

EO01

EO01

21

20

B

A

CPS LO

CPS LH

36

12

37

38

27

39

EO35

EO35

EO35

EO35

EO35

EO35

2

4

3

1

5

6

V5REF1

V5REF2

PPS1

PPS2

V5RTN1

V5RTN2

18

56

23

V5RTN2

CAM1

V5REF2

B

A

C

VSS

EO01

EO01

EO01

EO01

EO01

EO01

E

H

26

03

39

04

67

61

C

A

B

D

M

TPSPD

V5RTN1

TPSPU

V5REF1

MTR+

MTR-

S

N

Engine Control Module

Crankshaft 

Position 

Sensor

Accelerator 

Pedal Position 

Sensor

Electronic 

Throttle Body

Pre-catalytic Oxygen Sensor

Post-catalytic Oxygen Sensor

Camshaft Position Sensor

Vehicle Speed Sensor

To Instrument Cluster

FE02-5203b

Engine

Control System JL4G15-D

2-605

2.12.7 Diagnostic Information and Procedures
2.12.7.1 Diagnosis Description

Before  carry  out  the  control  system  diagnostic.  Refer  to

2.12.2

 

Description  and  Operation

and

2.12.3

 

System  Working  Principle

.

Understand and get familiar with control system working principle, and then start systematic diagnostic, so that it will help to determine
the correct diagnostic steps, more importantly, it also help to determine whether the customer described situation is normal.

Before any control system fault diagnostic, using the

2.2.7.2

 

Control System Check

as a starting point to guide the servie personnel

to take the next logical step for fault diagnosis. Understand and correctly use the diagnostic flow chart can reduce the diagnostic
time and avoid misjudge on components.

2.12.7.2 Control System Check

For 4G15-D engine control system check. Refer to the 4G18-D engine

2.2.7.2

 

Control System Check

.

2.12.7.3 Intermittent Fault Check

For 4G15-D engine intermittent fault check, please refer to the 4G18-D engine

2.2.7.3

 

Intermittent Fault Check

.

2.12.7.4 Symptoms Table

If a malfunction occurs, but it has been not stored in ECM DTC code (DTC), and its faulty reason can not be identified in the basic
diagnostic, carry out the diagnostic based on the following table listed order.

Symptoms

Suspected Faulty Items

Relevant Sections

Retardation, Engine Speed Decreases,
Speed Instability
Fault  Definition:  When  pressing  the
acceleration  pedal,  there  is  no
response. 

At 

any 

speed, 

this

malfunction may occur. Start the vehicle
for the first time (for example, start after
parking),  this  malfunction  is  usually
more  obvious.  In  severe  cases,  this
malfunction may lead to engine stalling.

1.ECM Power Supply Circuit

Refer to 

2.12.7.43

 

DTC P0562 P0563

2.  Intake  Manifold  Absolute  Pressure  (MAP)
Sensor

Refer to 

2.12.7.18

 

DTC P0107 P0108

3. Fuel Pressure Abnormal

Refer  to

2.13

 

Fuel  System  JL4G15-

D

in

2.13.1

 

Diagnostic  Information  and

Procedures

4. Injector Working Abnormal

5. Mixture Too Rich

Refer to 

2.12.7.26

 

DTC P0171 P0172

P1167 P1171 P2187 P2188

6. Mixture Too Lean

7. Ignition system: spark plug abnormal, ignition
wires abnormal.

Refer to

2.20

 

Ignition System JL4G15-

D

in

2.20.4

 

Diagnostic  Information  and

Procedures

8. Knock Sensor (KS) system, the ignition delay
is too great.

9. Crankshaft Position Sensor

Refer to 

2.12.7.35

 

DTC P0335 P0336

10. Thermostat Abnormal

2.18

 

Engine Cooling System JL4G15-

D

in

2.18.3

 

Diagnostic  Information  and

Procedures

11. Generators Working Abnormal

Refer  to

2.11

 

Starting  /  Charging

System  JL4G18-D

in

2.11.7

 

Diagnostic

Information and Procedures

Only when Air-Conditioning is working,
the engine stalls.

1. Air-Conditioning Signal Circuit

Refer to

8.2

 

Automatic Air-

conditioning

in

8.2.7

 

Diagnostic

Information and Procedures

2-606

Control System JL4G15-D

Engine