Mitsubishi Montero (2002-2004). Manual - part 600

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-97

STEP 2. Measure the sensor output voltage at engine 
coolant temperature sensor connector B-37 by 
backprobing.
(1) Do not disconnect the connector B-37.
(2) Turn the ignition switch to the "ON" position.

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

backprobing.

• When engine coolant temperature is −20°C (−4°F), volt-

age should be 3.9 and 4.5 volts.

• When engine coolant temperature is 0°C (32°F), voltage 

should be 3.2 and 3.8 volts.

• When engine coolant temperature is 20°C (68°F), volt-

age should be 2.3 and 2.9 volts.

• When engine coolant temperature is 40°C (104°F), volt-

age should be 1.3 and 1.9 volts.

• When engine coolant temperature is 60°C (140°F), volt-

age should be 0.7 and 1.3 volts.

• When engine coolant temperature is 80°C (176°F), volt-

age should be 0.3 and 0.9 volt.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?

YES : Go to Step 3.
NO :  Go to Step 5.

STEP 3. Check connector B-37 at the engine coolant 
temperature sensor 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 14.

AK200943

1

2

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-37

B-37(B)

AK201572

2

1

AB

B-37 HARNESS 
CONNECTOR: 
HARNESS SIDE

AK200943

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2

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-37

B-37(B)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-98

STEP 4. Using scan tool MB991502, check data list item 21: 
Engine Coolant Temperature Sensor.

CAUTION

To prevent damage to scan tool MB991502, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 to the data reading mode for item 

21, Engine Coolant Temperature Sensor.

• The engine coolant temperature and temperature 

shown with the scan tool should approximately match.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use Troubleshooting/
Inspection Service Points 

P.00-6

.

NO :  Replace the PCM. Then go to Step 14.

STEP 5. Check connector B-37 at engine coolant 
temperature sensor for damage.
Q: Is the connector in good condition?

YES : Go to Step 6.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 14.

ACX01539

16-PIN

MB991502

AC

AK200943

1

2

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-37

B-37(B)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-99

STEP 6. Measure the sensor supply voltage at engine 
coolant temperature sensor harness side connector B-37.
(1) Disconnect the connector B-37 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 between 4.5 and 4.9 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.5 and 4.9 volts?

YES : Go to Step 8.
NO :  Go to Step 7.

STEP 7. Check connector D-135 at PCM for damage.
Q: Is the connector in good condition?

YES : Replace the PCM. Then go to Step 14.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 14.

AK200943

1

2

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-37

B-37(B)

AK000234 AL

2 1

B-37 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK200947

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CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-100

STEP 8. Check the continuity at engine coolant 
temperature sensor harness side connector B-37.
(1) Disconnect the connector B-37 and measure at the harness 

side.

(2) Check for the continuity between terminal No. 2 and 

ground.

• Should be less than 2 ohms.

Q: Is the continuity normal?

YES : Go to Step 11.
NO :  Go to Step 9.

STEP 9. Check connector D-135 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 10.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 14.

AK200943

1

2

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-37

B-37(B)

AK000235

B-37 HARNESS
 CONNECTOR: 
COMPONENT SIDE

1

2

AL

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CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)