Mitsubishi Colt Ralliart. Manual - part 702

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-133

STEP 4. Connector check: B-106 engine control 
relay connector and A-114 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair or replace the connector.

STEP 5. Check harness between B-106 (terminal 
No. 4) engine control relay connector and A-104 
(terminal No. 1) No. 3 injector connector. 

NOTE: Before checking harness, check intermediate 
connector A-17 and B-112, and repair if necessary.

• Check power supply line for damage.

Q: Is the check result normal?

YES : 

 Go to Step 6 .

NO : 

Repair the damaged harness wire.

3

2

1

4

AK402084

J/B side 
connector

B-106

Connector: B-106
J/B (front side)

AC

AK402745

6

4

2

5

3

1

9

7

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10

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52

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56

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58

59

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61

62

63

64

65

66

L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

3

2

1

4

AK402084

J/B side 
connector

B-106

Connector: B-106
J/B (front side)

AC

AK402090

M

1

2

A-104(G)

AC

Connector: A-104

Harness side 
connector

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-134

STEP 6. Check harness between A-104 (terminal 
No. 2) No. 3 injector connector and A-114 
(terminal No. 23) engine-ECU connector

• Check earthing line for damage.

Q: Is the check result normal?

YES : 

 Go to Step 7 .

NO : 

Repair the damaged harness wire.

STEP 7. Fuel pressure measurement.

• Fuel pressure measurement (Refer to Fuel Pres-

sure Test 

P.13B-358

).

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Repair the fuel pressure.

STEP 8. M.U.T.-III diagnosis code.

• Reconfirmation of diagnosis code.

Q: Is the diagnosis code set?

YES : 

Replace engine-ECU.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use Troubleshooting/Inspection 

Service Points 

− How to Cope with 

Intermittent Malfunctions 

P.00-13

).

AK402090

M

1

2

A-104(G)

AC

Connector: A-104

Harness side 
connector

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

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51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-135

Code No. P0304: No. 4 Cylinder Misfire Detected

OPERATION

• Refer to Code No. P0204 No. 4 Injector System 

P.13B-107

.

FUNCTION

• If a misfire occurs while the engine is running, the 

engine speed changes for an instant.

• The engine-ECU checks for such changes in 

engine speed.

TROUBLE JUDGMENT

Check Conditions

• Engine speed is more than 500 r/min and is less 

than 4,500 r/min.

• Engine coolant temperature is more than -10°C.

• Volume efficiency is more than 35%

• Adaptive learning is completed for the vane 

which generates a crankshaft position signal.

• While the engine is running, excluding gear shift-

ing, deceleration, sudden acceleration/decelera-
tion and switching A/C compressor.

• When the variation in the throttle valve opening 

angle is small.

Judgement Criterion

• Misfire occurred more frequently than the limit 

during the last 200 revolutions

Or

• Misfire occurred more than the limit during the 

last 1,000 revolutions

PROBABLE CAUSES

• Ignition system related part(s) failed

• Low compression pressure

• Failed fuel system

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the ignition coil spark.

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Check ignition Circuit System (Refer to 
Inspection Procedure 26 

P.13B-327

).

STEP 2. Connector check: A-105 No. 4 injector 
connector

Q: Is the check result normal?

YES : 

 Go to Step 3 .

NO : 

Repair or replace the connector.

STEP 3. Check No. 4 injector itself.

• Check Injector itself (Refer to 

P.13B-367

).

Q: Is the check result normal?

YES : 

 Go to Step 4 .

NO : 

Replace the No. 4 injector.

AK402091

M

1

2

A-105(G)

AC

Connector: A-105

Harness side 
connector

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-136

STEP 4. Connector check: B-106 engine control 
relay connector and A-114 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair or replace the connector.

STEP 5. Check harness between B-106 (terminal 
No. 4) engine control relay connector and A-105 
(terminal No. 1) No. 4 injector connector. 

NOTE: Before checking harness, check intermediate 
connector A-17 and B-112, and repair if necessary.

• Check power supply line for damage.

Q: Is the check result normal?

YES : 

 Go to Step 6 .

NO : 

Repair the damaged harness wire.

3

2

1

4

AK402084

J/B side 
connector

B-106

Connector: B-106
J/B (front side)

AC

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

3

2

1

4

AK402084

J/B side 
connector

B-106

Connector: B-106
J/B (front side)

AC

AK402091

M

1

2

A-105(G)

AC

Connector: A-105

Harness side 
connector

Main

Index

Group

TOC