Mitsubishi Outlander (2003+). Manual - part 53

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-75

STEP 8. Connector check: C-137 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Check and repair harness between C-18 

(terminal No. 3) oxygen sensor connector 
and C-137 (terminal No. 92) engine-ECU 
connector.

œ

Check earthing line for damage.

NO : 

Repair.

STEP 9. Measure voltage at C-18 oxygen sensor 
(rear) connector.

œ

Use special tool test harness (MB991658) to con-
nect connector, and measure at pick-up harness.

œ

Engine: After warm-up

œ

Voltage between terminal No. 4 and earth.

OK:

600 

-

 1,000 mV when 200 mV or lower abrupt 

racing is done a few seconds after abrupt 
deceleration from 4,000 r/min.

Q: Is the check result normal?

YES : 

Go to Step 12 .

NO : 

Go to Step 10 .

STEP 10. Check oxygen sensor (rear) itself.

œ

Check oxygen sensor (rear) itself (Refer to 

3

13A



).

Q: Is the check result normal?

YES : 

 Go to Step 11 .

NO : 

Replace oxygen (rear) sensor.

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

AK300270

1 2

3 4

AB

Connector: C-18

Oxygen sensor (rear)

C-18

Harness side
connector

AK300270

1 2

3 4

AB

Connector: C-18

Oxygen sensor (rear)

C-18

Harness side
connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-76

STEP 11. Connector check: C-137 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Check and repair harness between C-18 

(terminal No. 4) oxygen sensor connector 
and C-137 (terminal No. 75) engine-ECU 
connector.

œ

Check output line for damage.

NO : 

Repair.

STEP 12. Measure voltage at C-137 engine-ECU 
connector.

œ

Measure engine-ECU terminal voltage.

œ

Transmission: Neutral

œ

Engine: After warm-up

œ

Voltage between terminal No. 75 and earth.

OK:

600 

-

 1,000 mV when 200 mV or lower abrupt 

racing is done a few seconds after abrupt 
deceleration from 4,000 r/min.

Q: Is the check result normal?

YES : 

Go to Step 14 .

NO : 

Go to Step 13 .

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

AK300270

1 2

3 4

AB

Connector: C-18

Oxygen sensor (rear)

C-18

Harness side
connector

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-77

STEP 13. Connector check: C-137 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Check and repair harness between C-18 

(terminal No. 4) oxygen sensor (rear) 
connector and C-137 (terminal No. 75) 
engine-ECU connector.

œ

Check output line for open circuit.

NO : 

Repair.

STEP 14. Connector check: C-137 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair.

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

AK300270

1 2

3 4

AB

Connector: C-18

Oxygen sensor (rear)

C-18

Harness side
connector

AK300254

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

AB

CONNECTOR: C-137

C-137

Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-78

Code No. P0141: Oxygen Sensor Heater (Rear) System <Sensor 2>

OPERATION

œ

Power is supplied to the heater power terminal 
(terminal No. 2) of the oxygen sensor (rear) con-
nector from the engine control relay (terminal No. 
1).

œ

The heater (terminal No. 1) of the oxygen sensor 
(rear) connector is controlled by the power tran-
sistor in the engine-ECU (terminal No. 54).

FUNCTION

œ

The power supply to the oxygen sensor heater 
(rear) is controlled by the ON/OFF control of the 
power transistor in the engine-ECU.

œ

Heating the oxygen sensor heater (rear) enables 
the oxygen sensor to provide good response 
even when the exhaust emission temperature is 
low.

AK300271

1

2

3

4

1 2

3 4

57 58

60 61

53

52

51

55

54

56

59

62

AB

B-17X

1

2

R

R

W-B

W-B

Y-R

Oxygen sensor (rear)

2

3

1

4

To engine-ECU

Engine-ECU

54

Engine 
control 
relay

Oxygen sensor (rear) heater circuit

C-18

(MU801688)

Battery

4

3

Wire colour code
B: Black  LG: Light green  G: Green  L: Blue  W: White  Y: Yellow  SB: Sky blue  BR: Brown  O: Orange  GR: Gray
R: Red  P: Pink  V:Violet

2

1

J/C (2) 
C-17

C-136