Mitsubishi Montero (2002-2004). Manual - part 639

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-253

STEP 2. Check the left bank heated oxygen sensor (rear).
(1) Disconnect the left bank heated oxygen sensor (rear) 

connector C-15 and connect test harness special tool, 
MB998464, to the connector on the left bank heated oxygen 
sensor (front) side.

(2) Warm up the engine until engine coolant 80

°C (176°F) or 

higher.

CAUTION

Be very careful when connecting the jumper wires; incor-
rect connection can damage the left bank heated oxygen 
sensor (rear).

(3) Use the jumper wires to connect terminal No. 1 (red clip) to 

the positive battery terminal and terminal No. 3 (blue clip) to 
the negative battery terminal.

(4) Connect a digital volt meter between terminal No. 2 (black 

clip) and terminal No. 4 (white clip).

(5) While repeatedly revving the engine, measure the heated 

oxygen sensor (rear) output voltage.

Standard value: 0.6 

− 1.0 volt

Q: Is the voltage between 0.6 and 1.0 volt?

YES : Go to Step 3.
NO :  Replace the left bank heated oxygen sensor (rear). 

Then go to Step 5.

AK201280

1

2

3

4

CONNECTOR: C-15

C-15(B)

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AKX01625AC

BLUE

RED

BLACK

JUMPER
WIRES

WHITE

MD998464

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-254

STEP 3. Check connector C-15 at left bank heated oxygen 
sensor (rear) and connector D-135 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 4.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 5.

AK201280

1

2

3

4

CONNECTOR: C-15

C-15(B)

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AK200947

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-255

STEP 4. Check for short circuit to ground between left 
bank heated oxygen sensor (rear) connector C-15 
(terminal No. 4) and PCM connector D-135 (terminal No. 
116).
NOTE: Check harness after checking intermediate connector 
E-112. IF intermediate connector is damaged, repair or replace 
it. Refer to Group 00E, Harness Connector Inspection 

P.00E-2

 

.
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 5.
NO :  Repair it. Then go to Step 5.

STEP 5. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

GROUP 13A, Procedure 6 

− Other Monitor 

P.13Ab-2

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0157 set?

YES : Retry the troubleshooting.
NO :  The inspection is complete.

AK201280

1

2

3

4

CONNECTOR: C-15

C-15(B)

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AK200947

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-256

DTC P0158: Heated Oxygen Sensor Circuit High Voltage (bank 2, sensor 2)

WHITE

BL

ACK

BL

ACK

WHITE

BL

ACK

BL

ACK

BL

ACK

AK201137

TO PCM

FROM MFI RELAY

96

116

2

4

3

1

2

1

4 5 6

3

E-112

LEFT BANK
HEATED OXYGEN
SENSOR (REAR)

POWERTRAIN CONTROL
MODULE (PCM)

10

9

1

3

7

4

3

1 2

C-15

MU802605

1

12

23 24 25 26

2

13

3

14

4

15

5

16

6

17

7

18

8

19

9

20 21 22

27 28 29 30 31 32 33

10 11

D-116

1
5

7 8

3 4
9 10

2
6

D-14

MU801335

Left Bank Heated Oxygen Sensor (rear) Circuit

9192

939495

96979899

100

105

113114

115116117

118119120

106

107108109

110111112

101102103

104

D-135

(MU803805)