Mitsubishi Montero (2002-2004). Manual - part 593

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-69

STEP 13. Check for harness damage between engine 
coolant temperature sensor connector B-37 (terminal No. 
1) and PCM connector D-135 (terminal No. 98).
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 14.
NO :  Repair it. Then go to Step 14.

STEP 14. 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 P116 set?

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

AK200943

1

2

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-37

B-37(B)

AK200947

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CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-70

DTC P0117: Engine Coolant Temperature Circuit Low Input

.

CIRCUIT OPERATION

• 5-volt voltage is applied to the engine coolant 

temperature sensor output terminal (terminal No. 
1) from the PCM (terminal No. 98) via the resistor 
in the PCM. The ground terminal (terminal No. 2) 
is grounded with (terminal No. 96).

• The engine coolant temperature sensor is a neg-

ative temperature coefficient type of resistor. It 
has the characteristic that when the engine cool-
ant temperature rises the resistor decreases.

• The engine coolant temperature sensor output 

voltage increases when the resistor increases 
and decreases when the resistor decreases.

.

YELLO

W

-GREEN

SKY B

ULE

AK201129

ENGINE COOLANT
TEMPERATURE SENSOR

POWERTRAIN CONTROL MODULE(PCM)

5 V

98

2

B-37

(MU802406)

96

1

Engine Coolant Temperature Sensor Circuit

1 2

9192

939495

96979899

100

105

113114

115116117

118119120

106

107108109

110111112

101102103

104

D-135

(MU803805)

AK200942

ENGINE COOLANT
TEMPERATURE SENSOR

AK200942AB

B-37(B)

CONNECTOR: B-37

AK201038AF

CONNECTOR: D-135

PCM

D-135(GR)

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-71

TECHNICAL DESCRIPTION

• The engine coolant temperature sensor converts 

the engine coolant temperature to a voltage and 
output it.

• The PCM checks whether this voltage is within a 

specified range.

.

DTC SET CONDITIONS

Check Conditions

• 2 seconds or more have passed since the staring 

sequence was completed.

Judgement Criteria

• Engine coolant temperature sensor output volt-

age has continued to be 0.1 volt or lower [corre-
sponding to coolant temperature of 140

°C 

(284

°F) or higher] for 2 seconds.

.

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

• Engine coolant temperature sensor failed.

• Open or shorted engine coolant temperature sen-

sor circuit, or loose connector.

• PCM failed.

DIAGNOSIS

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

STEP 1. 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 :  Go to Step 2.

STEP 2. Check connector B-37 at the engine coolant 
temperature sensor for damage.
Q: Is the connector in good condition?

YES : Go to Step 3.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 6.

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-72

STEP 3. Check for short circuit to ground between engine 
coolant temperature sensor connector B-37 (terminal No. 
1) and PCM connector D-135 (terminal No. 98).
Q: Is the harness wire in good condition?

YES : Go to Step 4.
NO :  Repair it. Then go to Step 6.

STEP 4. Check connector D-135 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 5.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 6.

AK200943

1

2

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-37

B-37(B)

AK200947

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CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)

AK200947

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CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)