Mitsubishi Montero (2002-2004). Manual - part 611

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-141

DTC P0135: Heated Oxygen Sensor Heater Circuit (bank 1, sensor 1)

TO PCM

TO PCM

WHITE-

BL

ACK

WHITE-

BL

ACK

AK201132

RED

BL

UE-RED

RIGHT BANK HEATED
OXYGEN SENSOR (FRONT)

4

1 2
3

B-22X

3

2

4

1

BATTERY

1

3

2

4

25

MFI
RELAY

3

1 2

4

B-07

MU802605

POWERTRAIN
CONTROL
MODULE (PCM)

Right Bank Heated Oxygen Sensor (front) Heater Circuit

1

2

3

5

6 7 8 9

4

20

21 22

232425

2627

10111213

14 15

16 1718

19

D-132

(MU803802)

AK201039

MFI RELAY

B-22X

AB

CONNECTOR: B-22X

AK201038

CONNECTOR: D-132

AB

PCM

D-132(GR)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-142

.

CIRCUIT OPERATION

• Power is supplied from the MFI relay (terminal 

No. 1) to the right bank heated oxygen sensor 
(front) heater.

• The PCM (terminal No. 25)

controls continuity to the right bank heated oxy-
gen sensor (front) heater by turning the power 
transistor in the PCM "ON" and "OFF".

.

TECHNICAL DESCRIPTION

• The PCM checks whether the heater current is 

within a specified range when the heater is ener-
gized.

.

DTC SET CONDITIONS

Check Conditions

• 60 seconds have elapsed from the start of the 

previous monitoring.

• Engine coolant temperature is higher than 20°C 

(68

°F).

• While the right bank heated oxygen sensor (front) 

heater is on.

• Battery positive voltage is at between 11 and 16 

volts.

Judgment Criteria

• Heater current of the right bank heated oxygen 

sensor (front) heater has continued to be lower 
than 0.16 ampere or higher than 7.5 ampere for 4 
seconds.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this code to be set are: )

• Open or shorted right bank heated oxygen sen-

sor (front) heater circuit.

• Open circuit in right bank heated oxygen sensor 

(front) heater.

• PCM failed.

AK201273

CONNECTOR: B-07

B-07(B)

AB

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-143

DIAGNOSIS

Required Special Tool:

• MD998464: Test Harness

STEP 1. Check harness connector B-07 at the right bank 
heated oxygen sensor (front) 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.

AK201274

1

2

3

4

CONNECTOR: B-07

B-07(B)

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-144

STEP 2. Check the right bank heated oxygen sensor 
(front).
(1) Disconnect right bank heated oxygen sensor (front) 

connector B-07 and connect test harness special tool, 
MD998464, to the connector on the right bank heated 
oxygen (front) sensor side.

(2) Measure the resistance between heated oxygen sensor 

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

Standard value: 4.5 

− 8.0 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 4.5 and 8.0 ohms 

[at 20

°C (68°F)]?

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

Then go to Step 12.

AK201274

1

2

3

4

CONNECTOR: B-07

B-07(B)

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

AKX01624

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

MD998464

BLUE

RED

AC