Mitsubishi Montero (2002-2004). Manual - part 255

SYMPTOM PROCEDURES

TSB Revision

SWS SYMPTOM PROCEDURES

54Bb-67

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TECHNICAL DESCRIPTION (COMMENT)
If the function does not work normally, the input cir-
cuit system from the switches or the ETACS-ECU 
may be defective (refer to "CIRCUIT OPERATION").

.

TROUBLESHOOTING HINTS

• The front door switches may be defective

• The column switch (turn-signal light and lighting 

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) 

• MB991862: SWS monitor kit 

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

• ETACS-ECU

• Column-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 "LOCK" (OFF) position.
(4) Operate scan tool MB991502 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."

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

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

Q: Is "OK" displayed on both the "ETACS ECU" and 

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

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

P.54Bb-25

."

"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

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AC204222AB

16-pin

13-pin

MB991502

MB991862

SYMPTOM PROCEDURES

TSB Revision

SWS SYMPTOM PROCEDURES

54Bb-68

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: OFF (key removed)

• Lighting switch: TAIL or HEAD

• Driver’s door: open

• Front passenger's door: closed

Operate scan tool MB991502 according to the procedure below 
to display "LGT MONI. ALRM."

1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "FUNCTION DIAG."
5. Select "BUZZER."
6. Select "LGT MONI. ALRM."

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

Q: Are normal conditions displayed for "HEADLIGHT SW", 

"TAILLIGHT SW", "IG SW IG1", "FRONT DOOR SW", "H/
L AUTO-CUT" and "BUZZER"?
YES : Replace the ETACS-ECU. The light reminder tone 

alarm function should now work normally.

NO : 

• Normal condition is not displayed on the 

"HEADLIGHT SW": Refer to Inspection Procedure 
O-6 "ETACS-ECU does not receive any signal 
from the headlight switch 

P.54Bc-31

."

• Normal condition is not displayed on the 

"TAILLIGHT SW": Refer to Inspection Procedure 
O-6 "ETACS-ECU does not receive any signal 
from the taillight switch 

P.54Bc-31

."

• Normal condition is not displayed on the "IG SW 

IG1": Refer to Inspection Procedure O-2 "ETACS-
ECU does not receive any signal from the ignition 
switch (IG1) 

P.54Bc-7

."

• Normal condition is not displayed on the "FRONT 

DOOR SW": Refer to Inspection Procedure O-5 
"ETACS-ECU does not receive any signal from 
the driver's or the front passenger's door switch 

P.54Bc-23

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• Normal condition is not displayed on the "H/L 

ITEM NO.

ITEM NAME

NORMAL 
CONDITION

ITEM 00

HEADLIGHT SW

Either of items 
is ON

ITEM 01

TAILLIGHT SW

ITEM 30

IG SW (IG1)

OFF

ITEM 32

FRONT DOOR SW 

ON

ITEM 35

H/L AUTO-CUT

OFF

ITEM 43

BUZZER

ON

AC204222AB

16-pin

13-pin

MB991502

MB991862

SYMPTOM PROCEDURES

TSB Revision

SWS SYMPTOM PROCEDURES

54Bb-69

AUTO-CUT": Refer to Inspection Procedure J-9 
"Headlight automatic shutdown function does not 
work normally 

P.54Bb-373

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• Normal condition is not displayed on the 

"BUZZER": Replace the ETACS-ECU. The light 
reminder tone alarm function should now work 
normally.

INSPECTION PROCEDURE B-3: Tone Alarm: Seat belt tone alarm function does not work normally.

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

."

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CIRCUIT OPERATION
 The ETACS-ECU operates the seat belt tone alarm 
function intermittently according to signals from the 
following switches:

• Ignition switch (IG1): ON

• Driver's seat belt switch: ON

 The ETACS-ECU operates the seat belt tone alarm 
function intermittently under the following conditions:

• Ignition switch: ON or START

• Driver’s seat belt: UNFASTENED

.

TECHNICAL DESCRIPTION (COMMENT)
If the function does not work normally, the input cir-
cuit system from the switches or the ETACS-ECU 
may be defective (refer to "CIRCUIT OPERATION").

.

TROUBLESHOOTING HINTS

• The driver's seat belt 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

Seat Belt Tone Alarm Function

SYMPTOM PROCEDURES

TSB Revision

SWS SYMPTOM PROCEDURES

54Bb-70

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 ETACS-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) When the ignition switch is turned to the "ON" position.
(4) Operate scan tool MB991502 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."

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

COMM CHK" menu for the "ETACS ECU" menu.

Q: Is "OK" displayed on the "ETACS ECU" menu?

YES : Go to Step 2.
NO :  Refer to Inspection Procedure A-3 "Communication 

with ETACS-ECU is not possible 

P.54Bb-25

."

AC204222AB

16-pin

13-pin

MB991502

MB991862