Mitsubishi Montero (2002-2004). Manual - part 296

SYMPTOM PROCEDURES

TSB Revision

SWS SYMPTOM PROCEDURES

54Bb-231

INSPECTION PROCEDURE G-1: Windshield Wiper and Washer: The windshield wiper does not work 
at all.

NOTE: This troubleshooting procedure requires the 
use of scan tool MB991502 and SWS monitor kit 
MB991862. For details on how to use the SWS mon-
itor, refer to "How to use SWS monitor 

P.54Ba-8

."

Windshield Wiper Motor Circuit

SYMPTOM PROCEDURES

TSB Revision

SWS SYMPTOM PROCEDURES

54Bb-232

.

CIRCUIT OPERATION

• The windshield wiper and washer switch sends a 

signal through the column-ECU (incorporated in 
the column switch) to the front-ECU. If the col-
umn-ECU sends a windshield wiper and washer 
switch "ON" signal to the front-ECU, the front-
ECU turns on the relay (incorporated in the front-
ECU), thus causing the windshield wiper and 
washer motor to be turned on.

• If the SWS communication line is defective, the 

front-ECU operates windshield wiper motor by 
using the other communication lines (wiper 
backup circuit) instead of that line. In this case, 
the windshield wiper works at low speed regard-
less of the windshield wiper and washer switch 
positions ("LO" or "HIGH").

.

TECHNICAL DESCRIPTION (COMMENT)
If the windshield wiper does not work at all, the wind-
shield wiper motor, column switch (windshield wiper 
and washer switch) or the front-ECU may be defec-
tive.

.

TROUBLESHOOTING HINTS

• The windshield wiper motor may be defective

• The column switch (windshield wiper and washer 

switch) may be defective

• The front-ECU may be defective

• The wiring harness or connectors may have 

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

AC205142AB

CONNECTOR: A-05

A-05(B)

AC205138

CONNECTOR: A-08X

AB

BATTERY

FRONT-ECU

A-08X

AC205116 AB

CONNECTOR: B-12

B-12 (B)

AC204170

CONNECTOR : D-28

BB

ACX02285

CONNECTORS: D-208, D-221

AI

D-208

JUNCTION BLOCK (FRONT VIEW)

D-221

SYMPTOM PROCEDURES

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SWS SYMPTOM PROCEDURES

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DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991502: Scan Tool (MUT-II) 

• MB991862: SWS Monitor Kit

STEP 1. Use scan tool MB991502 to select "ECU COMM 
CHK" on the SWS monitor display.
Check the following ECUs:

• Column-ECU

• Front-ECU

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 

(16-pin).

(2) Connect SWS monitor kit MB991862 to the data link 

connector (13-pin).

(3) Turn the ignition switch to the "ON" position.
(4) Operate scan tool MB991502 according to the procedure 

below to display "ECU COMM CHECK."

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

(5) Scan tool MB991502 should show "OK" on the "ECU 

COMM CHK" menus for both the "COLUMN ECU" and the 
"FRONT ECU" menus.

Q: Is "OK" displayed on the "COLUMN ECU" and "FRONT 

ECU" menu?
"OK" is displayed for all the items : Go to Step 2.
"NG" is displayed on the "COLUMN ECU" menu : Refer 

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

P.54Bb-

16

."

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

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

P.54Bb-32

."

AC204222AB

16-pin

13-pin

MB991502

MB991862

SYMPTOM PROCEDURES

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SWS SYMPTOM PROCEDURES

54Bb-234

STEP 2. Check the input signal by using "FUNCTION 
DIAG." menu of the SWS monitor.
Check the input signals from the following switches:

• Ignition switch: ACC

• Windshield wiper switch: INT

Operate the scan tool according to the procedure below to dis-
play "F.WIPER INT."

1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "FUNCTION DIAG."
5. Select "WIPER."
6. Select "F.WIPER INT."

Check that normal conditions are displayed on the items 
described in the table below.

Q: Are normal conditions displayed for "INT WIPER SW" 

and "FRONT ECU ACK"?
YES : Go to Step 3.
NO : 

• Normal condition is not displayed on the "INT 

WIPER SW." Replace the column switch. Verify 
that the windshield wiper works normally.

• Normal condition is not displayed on the "FRONT 

ECU SW." Replace the front-ECU. Verify that the 
windshield wiper works normally.

ITEM NO.

ITEM NAME

NORMAL 
CONDITION

ITEM 05

INT WIPER SW

ON

ITEM 70

FRONT ECU 
ACK

NORMAL ACK or 
HI-BEAM ACK

AC204222AB

16-pin

13-pin

MB991502

MB991862