Mitsubishi Montero (2002-2004). Manual - part 479

SIDE STEP LIGHT

TSB Revision

CHASSIS ELECTRICAL

54A-87

 STEP 5. Check side step light-ECU connector D-137 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector.
Q:  Is side step light-ECU connector D-137 in good 

condition?
YES : Go to Step 6.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. Verify that the side step light illuminate 

normally.

 STEP 6. Check the wiring harness between side step light-
ECU connector D-137 (terminal 2) and the ignition switch 
(IG1).

NOTE: Also check junction block connectors D-208 and D-210 
for loose, corroded, or damaged terminals, or terminals pushed 
back in the connector. If intermediate connector D-28, junction 
block connectors D-208 or D-210 is damaged, repair or replace 
the connector as described in GROUP 00E, Harness Connec-
tor Inspection 

P.00E-2

.

Q:  Is the wiring harness between side step light-ECU 

connector D-137 (terminal 2) and the ignition switch 
(IG1) in good condition?
YES : Replace the side step light-ECU. Verify that the side 

step light illuminate normally.

NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary. Verify that 
the side step light illuminate normally.

AC204170

CONNECTOR : D-137

HARNESS SIDE

D-137(GR)

D-137(GR)

AR

1

2

8 7

4

5

10

11

12

6

9

3

AC204170

CONNECTOR : D-137

HARNESS SIDE

D-137(GR)

D-137(GR)

AR

1

2

8 7

4

5

10

11

12

6

9

3

AC204191

CONNECTORS: D-208, D-210

D-208

AC

HARNESS SIDE

HARNESS SIDE

D-210

D-208

D-210

1

2

3

5

6

4

1

2

7 6

3

9

4

11

12

10

13

5

8

SIDE STEP LIGHT

TSB Revision

CHASSIS ELECTRICAL

54A-88

 STEP 7. Check the ground circuit to the side step light-
ECU. Test at side step light-ECU connector D-137.
(1) Disconnect side step light-ECU connector D-137 and 

measure the resistance available at the harness side of the 
connector.

(2) Measure the resistance value between terminal 12 and 

ground.

• The resistance should equal 2 ohms or less.

Q:  Is the measured resistance 2 ohms or less?

YES : Replace the side step light-ECU. Verify that the side 

step light illuminate normally.

NO :  Go to Step 8.

 STEP 8. Check side step light-ECU connector D-137 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector.
Q:  Is side step light-ECU connector D-137 in good 

condition?
YES : Go to Step 9.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. Verify that the side step light illuminate 

normally.

 STEP 9. Check the wiring harness between side step light-
ECU connector D-137 (terminal 7) and ground.
Q:  Is the wiring harness between side step light-ECU 

connector D-137 (terminal 7) and the ground in good 
condition?
YES : Replace the side step light-ECU. Verify that the side 

step light illuminate normally.

NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary. Verify that 
the side step light illuminate normally.

AC204170

CONNECTOR : D-137

HARNESS SIDE

D-137(GR)

D-137(GR)

AR

1

2

8 7

4

5

10

11

12

6

9

3

1

2

8 7

4

5

10

11

12

6

9

3

AC204601

CONNECTOR D-137
(HARNESS SIDE)

AB

AC204170

CONNECTOR : D-137

HARNESS SIDE

D-137(GR)

D-137(GR)

AR

1

2

8 7

4

5

10

11

12

6

9

3

AC204170

CONNECTOR : D-137

HARNESS SIDE

D-137(GR)

D-137(GR)

AR

1

2

8 7

4

5

10

11

12

6

9

3

SIDE STEP LIGHT

TSB Revision

CHASSIS ELECTRICAL

54A-89

INSPECTION PROCEDURE 2: One of the side step lights does not illuminate.

.

Side Step Light Circuit

AC204171

CONNECTOR : D-111

AG

AC204170

CONNECTORS : D-125, D-137

D-125

AW

D-137(GR)

AC204177

CONNECTOR : F-30        

AI

F-30(B)

AC204178

CONNECTOR : F-31

AI

F-31(B)

SIDE STEP LIGHT

TSB Revision

CHASSIS ELECTRICAL

54A-90

TECHNICAL DESCRIPTION (COMMENT) 
If one of the side step lights does not illuminate, the 
light bulb or the side step light-ECU may be defec-
tive.

.

TROUBLESHOOTING HINTS

• The side step light bulb may be defective

• The side step light-ECU may be defective

• The side step light assembly may be defective

• The wiring harness or connectors may have 

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

DIAGNOSIS

Required Special Tool:

• MB991223: Harness Set

 STEP 1. Check the side step light operation.
Q:  Which side step light does not illuminate?

 LH (FRONT and REAR) : Go to Step 2.
 RH (FRONT and REAR) : Go to Step 8.
 LH (FRONT) : Go to Step 14.
 LH (REAR) : Go to Step 15.
 RH (FRONT) : Go to Step 16.
 RH (REAR) : Go to Step 17.

STEP 2. Check the side step light operation.
(1) Disconnect side step light assembly (LH) connector F-31.
(2) When battery voltage is applied between the terminals, 

check that the side step light (LH) illuminate.

Q: Is side step light (LH) illuminate?

YES : Go to Step 3.
NO :  Replace the side step light harness. Verify that the 

side step light illuminate normally.

1 2

AC204165

SIDE STEP 
ASSEMBLY

AB