Mitsubishi Montero (2004+). Manual - part 764

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-313

STEP 2. Check the input signal by using "DATA LIST" 
menu of the SWS monitor.
Turn the passing switch to the "ON" position before checking 
input signals from the passing switch.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect the special tool. Refer to "How to connect SWS 

monitor 

P.54B-7

.

(2) Operate scan tool MB991958 according to the procedure 

below to display "COLUMN ECU."

1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "DATA LIST."
5. Select "COLUMN ECU."

(3) Check that normal conditions are displayed on the items 

described in the table below.

Q: Is normal condition displayed on the "PASSING SW"?

YES : Replace the front-ECU. When the passing switch is 

operated, the headlights (low-beam and high-beam) 
should illuminate normally.

NO :  Refer to Inspection Procedure O-6 "ETACS-ECU 

does not receive any signal from the passing switch 

P.54B-527

."

INSPECTION PROCEDURE J-5: Headlight and Taillight: Headlights do not illuminate when the lighting 
switch is at "TAIL," and "PASSING" position, but illuminate at low-beam when the switch is at "HEAD" 
position. At this position, the headlights cannot be changed into high beam by operating the dimmer 
switch.

NOTE: This troubleshooting procedure requires the 
use of scan tool MB991958 and SWS monitor kit 
MB991862. For details on how to use the SWS mon-
itor, refer to "How to use SWS monitor" 

P.54B-10

.

.

TECHNICAL DESCRIPTION (COMMENT)
If the headlights illuminate at low-beam regardless of 
the lighting switch positions, the headlight operation 
is in fail-safe mode.

.

TROUBLESHOOTING HINTS

• The column switch may be defective

• The front-ECU 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

ITEM NO.

ITEM NAME

NORMAL CONDITION

ITEM 03

PASSING SW

ON

AC309091

MB991911

MB991827

MB991824 

AB

MB991806

MB991862

DATA LINK
CONNECTOR 
(16-PIN)

DATA LINK
CONNECTOR 
(13-PIN)

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-314

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

• MB991813: SWS Monitor Kit

• MB991806: SWS Monitor Cartridge

• MB991812: SWS Monitor Harness (For Column-ECU)

• MB991822: Probe Harness

Use scan tool MB991958 to select "ECU COMM CHK" on 
the SWS monitor display.
Check the following ECUs:

• ETACS-ECU

• Column-ECU

• Front-ECU

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect the special tool. Refer to "How to connect SWS 

monitor 

P.54B-7

.

(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Operate scan tool MB991958 according to the procedure 

below to display "ECU COMM CHK."

1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "ECU COMM CHK."

(4) Scan tool MB991958 should show "OK" on the "ECU 

COMM CHK" menus for the "ETACS ECU", "COLUMN 
ECU" and "FRONT ECU" menus.

Q: Is "OK" displayed on the "ETACS ECU", "COLUMN 

ECU" and "FRONT ECU" menus?
"OK" are displayed for all the items : Replace the 

front-ECU. Verify that the headlights and the taillights 
illuminate normally.

"NG" is displayed on the "ETACS ECU" menu : Refer to 

Inspection Procedure A-3 "Communication with 
ETACS-ECU is not possible 

P.54B-42

."

"NG" is displayed on the "COLUMN ECU" menu : Refer 

to Inspection Procedure A-2 "Communication with 
column switch (column-ECU) is not possible 

P.54B-35

."

"NG" is displayed on the "FRONT ECU" menu : Refer to 

Inspection procedure A-4 "Communication with 
front-ECU is not possible 

P.54B-48

."

AC309091

MB991911

MB991827

MB991824 

AB

MB991806

MB991862

DATA LINK
CONNECTOR 
(16-PIN)

DATA LINK
CONNECTOR 
(13-PIN)

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-315

INSPECTION PROCEDURE J-6: Headlight and Taillight: Any of taillights, the position lights, the side 
marker light or the license plate lights do not illuminate.

FRONT-ECU

RELAY 
BOX

TAILLIGHT
RELAY

LICENSE
PLATE

LIGHT
ASSEMBLY

POSITION

LIGHT

 

(RH)

 

(LH)

(LH)            (RH)

REARLIGHT

TAILLIGHT
: RH

REARLIGHT

TAILLIGHT
: LH

REAR

COMBINATION
LIGHT 

(RH)

REAR

COMBINATION
LIGHT 

(LH)

Taillights, Position Lights and License Plate Lights Circuit

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-316

.

TECHNICAL DESCRIPTION (COMMENT)
If the position lights, the taillights, the side marker 
lights or the license plate lights do not illuminate, 
their bulb may be defective.

.

TROUBLESHOOTING HINTS

• The position light bulb may be defective

• The stop/taillight bulb may be defective

• The side marker light bulb may be defective

• The license plate light bulb may be defective

• The wiring harness or connectors may have 

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

AC204183

CONNECTOR : A-07X

AG

AC204167

CONNECTOR : A-18

A-18(GR)

AN

AC204166

CONNECTOR : A-36

AO

A-36(GR)

AC204170

CONNECTORS : D-28, D-125

BR

D-28

D-125

AC204171

CONNECTOR : D-111

AG

AC204178

CONNECTOR : F-10

F-10(GR)

AJ

AC204179

CONNECTORS : G-02, G-09, G-10, G-12, G-16

G-02(B)

G-16(B)

G-12(B)

G-10

G-09(B)

AI

AC204182

CONNECTOR : I-04

AF