Mitsubishi Montero (2004+). Manual - part 780

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-377

STEP 7. Check the input signal by using "FUNCTION 
DIAG." menu of the SWS monitor.
Check the input signals from the following switches:

• Ignition switch: ON

• Turn-signal light switch: RH

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 "TURN SIG.RH."

1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "FUNCTION DIAG."
5. Select "TURN SIGNAL."
6. Select "TURN SIG.RH."

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

described in the table below.

Q: Are normal conditions displayed on the "T/S RH SW" 

and "IG SW (IG1)"?
Normal conditions are displayed for all the items : Go to 

Step 8.

Normal condition is not displayed on the "T/S RH SW" : 

Normal condition is not displayed on the "T/S RH 
SW": Refer to Inspection Procedure O-6 
"ETACS-ECU does not receive any signal from the 
turn-signal RH switch 

P.54B-527

."

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.54B-505

."

ITEM NO.

ITEM NAME

NORMAL CONDITION

ITEM 10

T/S RH SW 

ON

ITEM 30

IG SW (IG1)

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-378

STEP 8. Check the input signal by using "FUNCTION 
DIAG." menu of the SWS monitor.
If the Ignition switch is turned to the "ON" position and the 
turn-signal light switch (LH) is turned on, normal conditions 
should be displayed on the items described in the table below.
Operate scan tool MB991958 according to the procedure below 
to display "TURN SIG.LH."

1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "FUNCTION DIAG."
5. Select "TURN SIGNAL."
6. Select "TURN SIG.LH."

Q: Do the scan tool display the items "T/S LH SW" is 

normal condition?
YES : Replace the ETACS-ECU. Verify that the turn-signal 

lights illuminate normally.

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

does not receive any signal from the taillight switch, 
the headlight switch, the passing light switch, the 
dimmer switch, the turn-signal light switch or switch 

P.54B-527

."

ITEM NO.

ITEM NAME

NORMAL 
CONDITION

ITEM 11

T/S LH 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-379

INSPECTION PROCEDURE K-2: Flasher Timer: Hazard warning lights do not illuminate.

.

CIRCUIT OPERATION
If the ETACS-ECU receives "ON" signal from the 
hazard warning light switch, the ETACS-ECU turns 
on the flasher timer (incorporated in the 
ETACS-ECU), thus causing the turn-signal lights to 
flash.

.

TECHNICAL DESCRIPTION (COMMENT)
If the hazard warning lights do not flash, the power 
supply line to the ETACS-ECU (dedicated to the 
turn-signal lights) or the ETACS-ECU may be defec-
tive.

.

TROUBLESHOOTING HINTS

• The hazard warning 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

Hazard Warning Light Circuit

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-380

• 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

STEP 1. Verify the turn-signal light operation.
Q: Do the turn-signal lights illuminate normally?

YES : Go to Step 2.
NO :  Refer to Inspection Procedure K-1 "Turn-signal lights 

does not flash when the turn-signal light switch is 
turned on 

P.54B-372

."

STEP 2. Check the input signal (by using the pulse check 
mode of the monitor.)
Check input signal from the hazard warning light 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 scan tool MB991502 to the data link connector 

(16-pin).

(2) Operate scan tool MB991958 according to the procedure 

below to display "PULSE CHECK."

1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "PULSE CHECK."

(3) Verify that scan tool MB991958 sounds when the hazard 

warning light switch is turned from "OFF" to "ON."

Q: Does scan tool MB991958 sound when the hazard 

warning light switch is turned from "OFF" to "ON"?
YES : Replace the ETACS-ECU. Verify that the hazard 

warning lights illuminate normally.

NO :  Refer to Inspection Procedure P-2 "ETACS-ECU does 

not receive any signal from the hazard warning light 
switch 

P.54B-549

."

AC307591 AB

MB991911

DATA LINK

CONNECTOR

MB991824

MB991827