Mitsubishi Lancer Evolution IX. Manual - part 399

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-71

STEP 6. Connector check: B-113 oxygen sensor 
(front) connector, C-117 and C-119 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Repair or replace the connector.

STEP 7. Check oxygen sensor (front) itself.

• Check oxygen sensor (front) itself (Refer to 

P.13A-404

).

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Replace the oxygen sensor (front).

AK305011

1

2

3

4

AB

Connector : B-113

Harness side 
connector

B-113(B)

Oxygen sensor(front)

AK501997

80

87

81

94

85

82

84

93

86

98

99

74

92

73

83

88

91

95

97 96

100

89

78

71

90

76

77

75

72
79

65

43
50

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41
48
60

61

64

46

47

58

59

67

68

45

56
66

52 51

44

53

62

54

63

57

55

AB

Connector: C-117, C-119

C-119 (GR)

C-117 (GR)

C-119 (GR)

C-117 (GR)

C-117 Harness side connector

C-119 Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-72

STEP 8. Check harness between B-113 oxygen 
sensor (front) connector and C-117 engine-ECU 
connector.

• Check output line for damage.

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Repair the damaged harness wire.

STEP 9. Connector check: Injector connector

a. B-22 (No. 1 injector connector)
b. B-20 (No. 2 injector connector)

c. B-18 (No. 3 injector connector)

d. B-17 (No. 4 injector connector)

Q: Are the check results normal?

YES : 

Go to Step 10 .

NO : 

Repair or replace the connector.

STEP 10. Check injector itself.

• Check Injector itself (Refer to 

P.13A-406

).

Q: Is the check result normal?

YES : 

Go to Step 11 .

NO : 

Replace the injector.

AK305011

1

2

3

4

AB

Connector : B-113

Harness side 
connector

B-113(B)

Oxygen sensor(front)

AK501996

80

87

81

94

85

82

84

93

86

98

99

74

92

73

83

88

91

95

97 96

100

89

78

71

90

76

77

75

72
79

AB

Connector: C-117

C-117 (GR)

C-117 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

AK305012

1

2

Connector : B-17,B-18,B-20,B-22

Harness side connector

B-22(B) B-20(B) B-18(B) B-17(B)

AB

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-73

STEP 11. Connector check: B-12X engine control 
relay connector and C-119 engine-ECU 
connector.

Q: Is the check result normal?

YES : 

Go to Step 12 .

NO : 

Repair or replace the connector.

STEP 12. Check harness between B-12X engine 
control relay connector and injector connector.

NOTE: Before checking harness, check intermediate 
connector C-105, and repair if necessary.

a. Check harness between B-12X (terminal No. 4) 

engine control relay connector and B-22 (terminal 
No. 1) No. 1 injector connector.

b. Check harness between B-12X (terminal No. 4) 

engine control relay connector and B-20 (terminal 
No. 1) No. 2 injector connector.

c. Check harness between B-12X (terminal No. 4) 

engine control relay connector and B-18 (terminal 
No. 1) No. 3 injector connector.

d. Check harness between B-12X (terminal No. 4) 

engine control relay connector and B-17 (terminal 
No. 1) No. 4 injector connector.

• Check power supply line for damage.

Q: Are the check results normal?

YES : 

Go to Step 13 .

NO : 

Repair the damaged harness wire.

AK305003

2

1

3

4

AB

Connector : B-12X

B-12X

Harness side 
connector

Relay box’s
triangle marks

AK501994

65

43
50

42
49

41
48
60

61

64

46

47

58

59

67

68

45

56
66

52 51

44

53

62

54

63

57

55

AB

Connector: C-119

C-119 (GR)

C-119 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

AK305003

2

1

3

4

AB

Connector : B-12X

B-12X

Harness side 
connector

Relay box’s
triangle marks

AK305012

1

2

Connector : B-17,B-18,B-20,B-22

Harness side connector

B-22(B) B-20(B) B-18(B) B-17(B)

AB

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-74

STEP 13. Check harness between injector 
connector and C-121 engine-ECU connector.

a. Check harness between B-22 (terminal No. 2) 

No. 1 injector connector and C-121 (terminal No. 
1) engine-ECU connector.

b. Check harness between B-20 (terminal No. 2) 

No. 2 injector connector and C-121 (terminal No. 
9) engine-ECU connector.

c. Check harness between B-18 (terminal No. 2) 

No. 3 injector connector and C-121 (terminal No. 
24) engine-ECU connector.

d. Check harness between B-17 (terminal No. 2) 

No. 4 injector connector and C-121 (terminal No. 
2) engine-ECU connector.

Q: Are the check results normal?

YES : 

Go to Step 14 .

NO : 

Repair the damaged harness wire.

STEP 14. Fuel pressure measurement.

• Fuel pressure measurement (Refer to 

P.13A-396

).

Q: Is the check result normal?

YES : 

Replace the engine-ECU.

NO : 

Repair.

AK305012

1

2

Connector : B-17,B-18,B-20,B-22

Harness side connector

B-22(B) B-20(B) B-18(B) B-17(B)

AB

AK501995

2

3

4

5

6

7

8

9

11

12

13

14

15

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17

18

19

20

30

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22

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24

25

26

27

28

29

31

32

33

34

35

1

10

AB

Connector: C-121

C-121 (GR)

C-121 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>