Mitsubishi Montero (2004+). Manual - part 789

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-413

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TECHNICAL DESCRIPTION (COMMENT)
If one of the fog lights does not illuminate, the fog 
light relay or the fog light bulb may be defective. If 
the fog light indicator light does not illuminate, the 
combination meter may be defective.

.

TROUBLESHOOTING HINTS

• The fog light bulb may be defective

• The combination meter 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. Verify that the fog lights and the fog light indicator 
light illuminate.
Q:  Which light does not illuminate?

Fog light (LH) : Go to Step 2.
Fog light (RH) : Go to Step 8.
Fog light indicator : Go to Step 14.
Fog lights (both RH and LH) : Go to Step 20.
All lights : Refer to Inspection procedure L-1 "Fog lights do 

not illuminate when the fog light switch is turned on 

P.54B-404

."

AC204183

CONNECTOR : A-13X

AH

AC204167

CONNECTORS : A-15, A-21, A-25

A-15

AQ

A-25(B)

A-21(B)

AC204166

CONNECTOR : A-31

AL

A-31(B)

AC204170

CONNECTORS : D-03, D-04, D-28, D-30

BL

D-03(GR)

D-04(GR)

D-28

D-30

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-414

STEP 2. Check the fog light bulb (LH).
(1) Remove the fog light bulb (LH).
(2) Verify that the fog light bulb (LH) is not damaged or burned 

out.

Q: Is the fog light bulb (LH) in good condition?

YES : Go to Step 3.
NO :  Replace the fog light bulb (LH). Verify that the fog 

lights illuminate normally.

STEP 3. Check fog light (LH) connector A-21 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is fog light (LH) connector A-21 in good condition?

YES : Go to Step 4.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. Verify that the fog lights illuminate normally.

STEP 4.Check the ground circuit to the fog light (LH). Test 
at fog light (LH) connector A-21.
(1) Disconnect fog light (LH) connector A-21 and measure the 

resistance available at the wiring harness side of the 
connector.

(2) Measure the resistance value between terminal 2 and 

ground.

• The resistance should equal 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES : Go to Step 6.
NO :  Go to Step 5.

AC204167

CONNECTOR : A-21

HARNESS 
SIDE

A-21(B)

A-21(B)

AJ

1

2

AC204167

CONNECTOR : A-21

HARNESS 
SIDE

A-21(B)

A-21(B)

AJ

1

2

AC100270

1

2

AB

CONNECTOR A-21
(HARNESS SIDE)

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-415

STEP 5. Check the wiring harness between fog light (LH) 
connector A-21 (terminal 2) and ground.

NOTE: Also check intermediate connector A-25 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the 
connector. If intermediate connector A-25 is damaged, repair or 
replace the damaged component(s) as described in GROUP 
00E, Harness Connector Inspection 

P.00E-2

.

Q: Is the wiring harness between fog light (LH) connector 

A-21 (terminal 2) and ground in good condition?
YES : No action is necessary and testing is complete.
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 fog lights illuminate normally.

STEP 6. Check joint connector (2) A-15 for loose, corroded 
or damaged terminals, or terminals pushed back in the 
connector. 
Q: Is joint connector (2) A-15 in good condition?

YES : Go to Step 7.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. Verify that the fog lights illuminate normally.

AC204185

CONNECTORS : A-21, A-25

A-21(B)

A-25(B)

AF

A-25(B)

HARNESS SIDE

A-21(B)

1

2

4

2

3

1

AC204167

CONNECTOR : A-15

AD

14

13

4

1112

5

3

10

8 9

2

7

1

6

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-416

STEP 7. Check the wiring harness between joint connector 
(2) A-15 (terminal 3) and fog light (LH) connector A-21 
(terminal 1).

NOTE: Also check intermediate connector A-25 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the 
connector. If intermediate connector A-25 is damaged, repair or 
replace the damaged component(s) as described in GROUP 
00E, Harness Connector Inspection 

P.00E-2

.

Q: Is the wiring harness between joint connector (2) A-15 

(terminal 3) and fog light (LH) connector A-21 (terminal 
1) in good condition?
YES : No action is necessary and testing is complete.
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 fog lights illuminate normally.

STEP 8. Check the fog light bulb (RH).
(1) Remove the fog light bulb (RH).
(2) Verify that the fog light bulb (RH) is not damaged or burned 

out.

Q: Is the fog light bulb (RH) in good condition?

YES : Go to Step 9.
NO :  Replace the fog light bulb (RH). Verify that the fog 

lights illuminate normally.

AC204185

CONNECTORS : A-15, A-21, A-25

A-21(B)

A-15

AC

A-15

A-25

HARNESS SIDE

A-21(B)

A-25(B)

14

13

4

1112

5

3

10

8 9

2

7

1

6

1

2

4

2

3

1