2

1

Cylinder No.4 Fuel Injector

FE02-5070b

(a)

Disconnect the fuel injector wiring harness connector EO14.

(b)

Measure resistance between the two fuel injector terminals.

Standard Resistance: 11.6-12.4 Ω at 20°C(68 ºF)

(c)

Connect the fuel injector wiring harness connector EO14.

No

replace fuel injector. Refer to 

2.2.8.2

 

Fuel

Injector Replacement

.

Yes

Step 3

Measure fuel injector working power supply.

FE02-5267b

2

1

Cylinder No.4 Fuel Injector Harness 
Connector EO14

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect cylinder No.4 fuel injector wiring harness
connector EO14.

(c)

Turn the ignition switch to "ON" position.

(d)

Measure voltage between cylinder No.4 fuel injector wiring
harness connector EO14 terminal No.2 and a reliable ground.

Standard Voltage: 11-14 V

(e)

Connect cylinder No.4 fuel injector wiring harness connector
EO14.

Voltage normal?

No

Go to step 5

Yes

Step 4

Check the fuel injector control circuit.

FE02-5268b

2

1

Cylinder No.4 Fuel Injector Harness 
Connector EO14

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect cylinder No.4 fuel injector wiring harness
connector EO14.

(c)

Connect a light-emitting diodes test lamp to the fuel injector
wiring harness connector EO14 terminal No.1 and 2.

(d)

Start the engine.

(e)

Observe whether test lamp is flashing.

Is the test lamp flashing?

No

Go to step 6

Yes

Go to step 7

Engine

Control System JL4G15-D

2-711

Step 5

Check and repair cylinder No.4 fuel injector power circuit.

1413 12 1110

5

1

2

3

4

6

7

8

9

J

L

K

I

G

D

C

B

E

F

A

86

86

30

87

85

86

86

87

87

87

30

30

30

85

85

85

2

2

3

3

5

5

1

1

1

2

5 3

1

2

5 3

86

87

30

1

1

2

5
3

2

5
3

85

EF14

EF24

EF28

EF27

EF26

EF18

EF07

EF06

EF30

EF19

EF20

EF21

EF22

EF23

EF25

EF15

EF16

EF17

EF13

EF12

EF1

1

EF10

EF09

EF08

EF05

EF04

EF03

EF02

EF01

G

1

2

5 3

2

1

Cylinder No.4 Fuel Injector Harness 
Connector EO14

FE02-5269b

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect the fuel injector wiring harness connector EO14.

(c)

Remove the engine main relay.

(d)

Measure resistance between cylinder No.4 fuel injector
wiring harness connector EO14 terminal No.2 and engine
main relay terminal No.3.

(e)

Measure resistance between cylinder No.4 fuel injector
wiring harness connector EO14 terminal No.2 and a reliable
ground.

Test Items

Standard Value

Resistance Between EO14 (2) and Main
Relay Terminal No.3

Less than 1 Ω

Resistance Between EO14 (2) and A
Reliable Ground

10 kΩ or higher

(f)

Install the engine main relay.

(g)

Connect cylinder No.4 fuel injector wiring harness connector
EO14.

Exclude fuel injector power circuit malfunction.

Next

Go to step 9

Step 6

Check cylinder No.4 fuel injector control circuit.

2

1

1

17

33

53

54

55

56

57

58

59

60

61

62

63

64

66

67

68

69

70

71

72

73

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

65

Cylinder No.4 Fuel Injector Harness 
Connector EO14

ECM Harness Connector EO01

FE02-5270b

(a)

Turn the ignition switch to "OFF" position.

(b)

Disconnect cylinder No.4 fuel injector wiring harness
connector EO14.

(c)

Disconnect ECM harness connector EO01.

(d)

Measure resistance between cylinder No.4 fuel injector
wiring harness connector EO14 terminal No.1 and ECM
harness connector terminal No.66. Check whether the circuit
is open. Otherwise, repair the faulty part.

(e)

Measure resistance between cylinder No.4 fuel injector
wiring harness connector EO14 terminal No.1 and a reliable
ground. Check whether the circuit is short to ground.
Otherwise, repair the faulty part.

(f)

Measure voltage between cylinder No.4 fuel injector wiring
harness connector EO14 terminal No.1 and a reliable ground.
Check whether the circuit is short to power supply. Otherwise,
repair the faulty part.

Test Items

Standard Value

Resistance Between EO14 (1) and EO01
(66)

Less than 1 Ω

2-712

Control System JL4G15-D

Engine

Resistance Between EO14 (1) and a reliable
ground

10 kΩ or higher

voltage between EO14 (1) and A Reliable
Ground

0 V

Execute next step as per normal.

Next

Step 7

Check ECM power supply circuit.

(a)

Check whether ECM power supply circuit is normal.

(b)

Check whether ECM ground circuit is normal.

No

Repair the faulty part.

Yes

Step 8

Replace ECM.

(a)

Carry out crankshaft self learn after ECM replacement. Refer
to 

2.12.7.11

 

Crankshaft Position Sensor (CKP) Learn

.

Next

Step 9

Use scan tool to confirm whether the DTC code is stored again.

(a)

Connect scan tool to the datalink connector.

(b)

Turn the ignition switch to "ON" position.

(c)

Clear DTC code.

(d)

Start and run the engine at idle speed to warm up the engine
for at least 5 min.

(e)

Road test the vehicle for at least 10 min.

(f)

Read control system DTC code again to confirm that the
system has no DTC code.

No

Intermittent Fault. Refer to 

2.2.7.3

 

Intermittent

Fault Check

.

Yes

Step 10

Diagnostic completed.

5. Repair Instructions:

Replace the fuel injector. Refer to 

2.2.8.2

 

Fuel Injector Replacement

.

2.12.7.33 DTC P0300

1. DTC Descriptor:

DTC

P0300

One or More Cylinder Misfire

Engine

Control System JL4G15-D

2-713

The engine control module (ECM) uses information from the crankshaft position (CKP) sensor and the camshaft position (CMP)
sensors to determine when an engine misre is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder
ECM is able to detect individual misre events. When a misfire happens, unburnt mixture will be discharged into the exhaust system
and burnt in the exhaust system. A misre rate that is high enough can cause 3-way catalytic converter damage. The malfunction
indicator lamp (MIL) will ash ON and OFF when the conditions for catalytic converter damage are present. A DTC will be set.

2. DTC Code Set Up and Removal Conditions:

DTC Code

DTC Detection Strategy

Conditions For Setting The DTC

(Control Strategy)

Fault Locations

P0300

Under stable operating
conditions, ECM detects the
crankshaft rotation speed
fluctuations.

Under stable operating conditions,
when ECM detect fluctuations in the
crankshaft rotation speed exceeds
the preset threshold value and when
a mild misfire occurs, there is no
emergency control programs.
System only records the DTC code
and data flow, and malfunction lamp
light. When there a serious misfire,
the system will be forced into the
open-loop control mode, and the
oxygen sensor learn is not allowed.
The malfunction lamp will flash at 1
Hz frequency.

1. Connector Loose or Poor

Connection

2. Vacuum Tube Hose Broken or

Loose

3. Ignition System

4. Fuel Injectors

5. Fuel Pressure

6. Intake Air Pressure Sensor

7. Engine Coolant Temperature

Sensor

8. Cylinder Compression Pressure

9. Valve Clearance and Timing

10. Evaporative Emission Control

System

11. Purged Crankcase Ventilation

System

12. Intake System

13. Poor Exhaust System

Ventilation

14. ECM

2-714

Control System JL4G15-D

Engine