Mitsubishi Montero (2002-2004). Manual - part 642

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-265

DIAGNOSIS

Required Special Tool:

• MD998464: Test Harness Set

STEP 1. Check harness connector C-15 at the left bank 
heated oxygen sensor (rear) for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 2.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12. 

AK201280

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2

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4

CONNECTOR: C-15

C-15(B)

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-266

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

(1) Disconnect left bank heated oxygen sensor (rear) connector 

C-15 and connect test harness special tool, MD998464, to 
the connector on the left bank heated oxygen (rear) sensor 
side.

(2) Measure the resistance between heated oxygen sensor 

connector terminal No. 1 (red clip) and terminal No. 3 (blue 
clip).

Standard value: 11 

− 18 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 11 and 18 ohms [at 

20

°C (68°F)]?

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

Then go to Step 12.

AK201280

1

2

3

4

CONNECTOR: C-15

C-15(B)

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AKX01624

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

MD998464

BLUE

RED

AC

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-267

STEP 3. Measure the power supply voltage at left bank 
heated oxygen sensor (rear) harness side connector C-15.
(1) Disconnect the connector C-15 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 1 and ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 5.
NO :  Go to Step 4.

STEP 4. Check harness connector B-22X at the MFI relay 
for damage.
Q: Is the harness connector in good condition?

YES : Check harness connectors E-114 and D-116 at 

intermediate connector for damage, and repair or 
replace as required. Refer to GROUP 00E, Harness 
Connector Inspection. If intermediate connectors E-
114 and D-116 are in good condition, repair harness 
wire between MFI relay connector B-22X (terminal 
No. 1) and left bank heated oxygen sensor (rear) 
connector C-15 (terminal No. 1) because of open 
circuit or short circuit to ground. Then go to Step 12.

NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12.

AK201280

1

2

3

4

CONNECTOR: C-15

C-15(B)

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AKX01498

C-15 HARNESS 
CONNECTOR: 
COMPONENT SIDE

1

2

3

4

AZ

AK200951

2 1

3

4

B-22X

AB

CONNECTOR: B-22X

HARNESS 
CONNECTOR: 
COMPONENT SIDE

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-268

STEP 5. Measure the power supply voltage at PCM 
connector D-132 by backprobing.
(1) Do not disconnect the connector D-132.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 18 and ground 

by backprobing.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 8.
NO :  Go to Step 6.

STEP 6. Check harness connector D-132 at PCM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 7.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 12. 

AK200938

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12

13

AB

CONNECTOR: D-132

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-132(GR)

1

2

3

5

6 7 8 9

4

20

21 22

232425

2627

10111213

14 15

16 1718

19

AK201413

D-132 HARNESS 
CONNECTOR: 
HARNESS SIDE

AB

AK200938

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AB

CONNECTOR: D-132

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-132(GR)