Mitsubishi Outlander (2003+). Manual - part 48

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-55

STEP 19. Connector check: C-137 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Check and repair harness between B-06 

(terminal No. 2) throttle position sensor 
connector and C-137 (terminal No. 84) 
engine-ECU connector.

œ

Check output line for short circuit and 
damage.

NO : 

Repair.

STEP 20. Measure voltage at C-137 engine-ECU 
connector

œ

Measure engine-ECU terminal voltage.

œ

Ignition switch: ON

œ

Voltage between terminal No. 84 and earth.

OK:

Accelerator pedal fully released: 0.535 

-

 0.735 

V

Accelerator pedal fully depressed: 4.5 

-

 5.0 V

Q: Is the check result normal?

YES : 

Go to Step 22 .

NO : 

Go to Step 21 .

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

AK300263

2 1

3

4

AB

B-06 (B)

Harness side connector

Connector: B-06

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-56

STEP 21. Connector check: C-137 engine-ECU 
connector

Q: Is the check result normal? 

YES : 

Check and repair harness between B-06 

(terminal No. 2) throttle position sensor 
connector and C-137 (terminal No. 84) 
engine-ECU connector.

œ

Check output line for open circuit and 
damage.

NO : 

Repair.

STEP 22. Connector check: C-137 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Repair.

Code No. P0125: Feedback system monitor

OPERATION

œ

Refer to P0201 injector circuit 

3

13A



.

Refer to P0202 injector circuit 

3

13A



.

Refer to P0203 injector circuit 

3

13A



.

Refer to P0204 injector circuit 

3

13A



.

œ

Refer to P0130 Oxygen sensor (front) circuit 

3

13A



.

FUNCTION

œ

The engine-ECU effects air-fuel ratio feedback 
control in accordance with the signals from the 
heater oxygen sensor (front).

œ

If the heated oxygen sensor (front) has deterio-
rated, corrections will be made by the heated oxy-
gen sensor (rear).

œ

diagnosis code P0125 becomes stored in mem-
ory if a failure is detected in the above air/fuel 
ratio feedback control system.

TROUBLE JUDGMENT

Check Conditions

œ

The engine coolant temperature approximately. 
82

•

C or more.

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

AK300263

2 1

3

4

AB

B-06 (B)

Harness side connector

Connector: B-06

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-57

œ

Within the range of air-fuel ratio feedback opera-
tion.

œ

Not in low speed operation.

Judgment Criteria

œ

The oxygen sensor output voltage is not deviated 
from 0.5 V for 30 seconds.

PROBABLE CAUSE

œ

Failed oxygen sensor (front)

œ

Harness damage in oxygen sensor (front) circuit 
or loose connector contact

œ

Failed oxygen sensor (rear)

NOTE: When the oxygen sensor (front) begins to 
deteriorate, the oxygen sensor output voltage will 
deviate from the voltage when the sensor was new 
(normally 0.5 volt at stoichiometric ratio). This devia-
tion will be corrected by the oxygen sensor (rear).If 
the oxygen sensor (rear) responds poorly because it 
has deteriorated, it will improperly correct the oxygen 
sensor (front). Thus, even when closed loop control 
is being effected, the fluctuation of the oxygen sen-
sor (front) output voltage decreases, without inter-
secting with 0.5 volt. As a result, there is a possibility 
of diagnosis code P0125 becoming registered.

œ

Failed fuel system

œ

Failed exhaust system

œ

Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. MUT-II self-diag code

Q: Is any other diagnosis code than P0170 output?

YES : 

Inspection chart for diagnosis code (Refer 

to 

3

13A



).

NO : 

Go to Step 2 .

STEP 2.MUT-II data list

œ

Refer to Data list reference table 

3

13A



.

a. Item 12: Air flow sensor
b. Item 21: Engine coolant temperature sensor

c. Item 25: Barometric pressure sensor

d. Item 69: Oxygen sensor (rear)

Q: Are the check results normal?

YES : 

 Go to Step 3 .

NO : 

Perform the diagnosis code classified check 
procedure for the sensor that has shown an 
abnormal data valve (Refer to Inspection 
Chart for Diagnosis Codes 

3

13A



).

STEP 3.Check for intake of air from intake hose 
and inlet manifold.

Q: Is the check result normal?

YES : 

 Go to Step 4 .

NO : 

Repair.

STEP 4.Check for leakage of exhaust emission 
from exhaust manifold.

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair.

STEP 5.Check throttle body (throttle valve 
portion) for contamination. 

Q: Is the check result normal?

YES : 

 Go to Step 6 .

NO : 

Clean throttle body (throttle valve portion) 
(Refer to 

3

13A



).

STEP 6. Connector check: B-112 oxygen sensor 
(front) connector, C-137 engine-ECU connector

Q: Is the check result normal?

YES : 

 Go to Step 7 .

NO : 

Repair.

AK300264

1

2

3

4

AB

B-112 (B)

Harness side connector

Oxygen sensor (front)

Connector: B-112

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-58

STEP 7. Check oxygen sensor (front) itself.

œ

Check oxygen sensor (front) itself (Refer to 

3

13A



).

Q: Is the check result normal?

YES : 

 Go to Step 8 .

NO : 

Replace oxygen sensor (front).

STEP 8. Check harness between B-112 oxygen 
sensor (front) connector and C-137 engine-ECU 
connector.

œ

Check output line for damage.

Q: Is the check result normal?

YES : 

 Go to Step 9 .

NO : 

Repair.

STEP 9. Connector check: Injector connector

a. B-01 (No.1 injector connector)
b. B-02 (No.2 injector connector)

c. B-04 (No.3 injector connector)

d. B-05 (No.4 injector connector)

Q: Is the check result normal?

YES : 

 Go to Step 10 .

NO : 

Repair.

STEP 10. Check injector itself.

œ

Check Injector itself (Refer to 

3

13A



).

Q: Is the check result normal?

YES : 

 Go to Step 11 .

NO : 

Replace injector.

AK300264

1

2

3

4

AB

B-112 (B)

Harness side connector

Oxygen sensor (front)

Connector: B-112

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

AK300265

M

1

2

Harness side connector

Connector: B-01, B-02, B-04, B-05

B-02 (GR)

AB

B-01 (GR) B-02 (GR) B-04 (GR) B-05 (GR)