Mitsubishi Montero (2002-2004). Manual - part 366

INPUT SIGNAL PROCEDURES

TSB Revision

SWS INPUT SIGNAL PROCEDURES

54Bc-11

CIRCUIT OPERATION
The ETACS-ECU operates the fog lights according to 
signal from the fog light switch.

.

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the fog lights do not work 
normally. If the signal is not normal, the fog light 
switch or the ETACS-ECU may be defective.

.

TROUBLESHOOTING HINTS

• The fog light switch may be defective

• The ETACS-ECU 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 Tools:

• MB991223: Harness Set

• MB991502: Scan Tool (MUT-II)

STEP 1. Check the fog light switch.
Remove the fog light switch. Then check continuity between 
the switch terminals.

Q: Is the fog light switch in good condition?

YES : Go to Step 2.
NO :  Repair the fog light switch. If the for light switch 

operates normally, it indicates that a correct signal is 
sent from the fog light switch.

STEP 2. Check the ground circuit to the fog light switch. 
Test at fog light switch connector D-127.
(1) Disconnect fog light switch connector D-127 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 5.
NO :  Go to Step 3.

SWITCH 
POSITION

TESTER 
CONNECTION

SPECIFIED 
CONDITION

Released

1 

− 2

Open circuit

Pressed

1 

− 2

Less than 2 ohms

ACX00797

AC204170

CONNECTOR : D-127

HARNESS SIDE

AP

1

2

3

4

D-127

4 3 2 1

5

6

ACX01597AB

CONNECTOR D-127
(HARNESS SIDE)

INPUT SIGNAL PROCEDURES

TSB Revision

SWS INPUT SIGNAL PROCEDURES

54Bc-12

STEP 3. Check fog light switch connector D-127 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is fog light switch connector D-127 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

. Repair the fog light switch. If the for light 

switch operates normally, it indicates that a correct 
signal is sent from the fog light switch.

STEP 4. Check the wiring harness between fog light switch 
connector D-127 (terminal 2) and ground.

NOTE: Also check joint connector D-30 for loose, corroded, or 
damaged terminals, or terminals pushed back in the connector. 
If joint connector D-30 is damaged, Repair or replace the dam-
aged component(s) as described in GROUP 00E, Harness 
Connector Inspection 

P.00E-2

.

Q: Is the wiring harness between fog light switch 

connector D-127 (terminal 2) and the 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. If the for light 
switch operates normally, it indicates that a correct 
signal is sent from the fog light switch.

AC204170

CONNECTOR : D-127

HARNESS SIDE

AP

1

2

3

4

D-127

AC204170

CONNECTOR : D-127

HARNESS SIDE

AP

1

2

3

4

D-127

AC204170

CONNECTOR : D-30

AJ

9 10

8

6 7

31 32

30

29

18 19 20 21

5

4

2

1

3

27

26

24

23

25

12 13 14 15 16 17

28

11
22
33

INPUT SIGNAL PROCEDURES

TSB Revision

SWS INPUT SIGNAL PROCEDURES

54Bc-13

STEP 5. Check fog light switch connector D-127 and 
ETACS-ECU connector D-224 for loose, corroded or 
damaged terminals, or terminals pushed back in the 
connector.
Q: Are fog light switch connector D-127 and ETACS-ECU 

connector D-224 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

. If the for light switch operates normally, it 

indicates that a correct signal is sent from the fog light 
switch.

STEP 6. Check the wiring harness between fog light switch 
connector D-127 (terminal 1) and ETACS-ECU connector D-
224 (terminal 24).
Q: Is the wiring harness between fog light switch 

connector D-127 (terminal 1) and ETACS-ECU connector 
D-224 (terminal 24) in good condition?
YES : Replace the ETACS-ECU. If the for light switch 

operates normally, it indicates that a correct signal is 
sent from the fog light switch.

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. If the for light 
switch operates normally, it indicates that a correct 
signal is sent from the fog light switch.

AC204170

CONNECTOR : D-127

HARNESS SIDE

AP

1

2

3

4

D-127

AC204174

CONNECTOR : D-224

AD

D-224(B)

D-224(B)

HARNESS SIDE

21

23

24

22

32

3433

31

26

27

28

3029

38

39

40

36

37

25

35

AC204170

CONNECTOR : D-127

HARNESS SIDE

AP

1

2

3

4

D-127

AC204174

CONNECTOR : D-224

AD

D-224(B)

D-224(B)

HARNESS SIDE

21

23

24

22

32

3433

31

26

27

28

3029

38

39

40

36

37

25

35

INPUT SIGNAL PROCEDURES

TSB Revision

SWS INPUT SIGNAL PROCEDURES

54Bc-14

INSPECTION PROCEDURE O-4: ETACS-ECU does not receive "R" position signal from the 
transmission range switch.

Transmission Range Switch Input Circuit

AC204395

CONNECTOR : C-04

A-04(B)

AC

AC204170

CONNECTOR: D-01

AY