Mitsubishi Galant (2004+). Manual - part 299

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-387

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 for the items described in the table below.
(1) Operate scan tool MB991958 according to the procedure 

below to display "TURN SIG.LH."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "TURN SIGNAL."
g. Select "TURN SIG.LH."

(2) Check that normal conditions are displayed for the item 

described in the table below.

Q: Do the scan tool display the item "T/S LH SW" as 

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

lights illuminate normally.

NO :  Refer to Inspection Procedure M-5 "ETACS-ECU 

does not receive any signal from the turn-signal light 
switch 

P.54B-505

."

ITEM No.

ITEM NAME

NORMAL CONDITION

ITEM 11

T/S LH SW

ON

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-388

INSPECTION PROCEDURE I-2: Flasher Timer: Hazard warning lights do not flash when the hazard 
warning light switch is turned on.

.

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

• Trouble in input signal system

• The wiring harness or connectors may have 

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

• The ETACS-ECU may be defective

BATTERY

RELAY
BOX

HAZARD
WARNING
LIGHT SWITCH

· FRONT COMBINATION
  LIGHT (LH)
· REAR COMBINATION
  LIGHT (LH)

· FRONT COMBINATION
  LIGHT (RH)
· REAR COMBINATION
  LIGHT (RH)

ETACS-ECU

TURN-SIGNAL
LIGHT RELAY: LH

TURN-SIGNAL
LIGHT RELAY: RH

JUNCTION BLOCK SIDE

JUNCTION BLOCK

Hazard Warning Light Circuit

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-389

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

• MB991910: MUT-III Main Harness A

STEP 1. Check the turn-signal lights.
Q: Do the turn-signal lights illuminate normally?

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

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

P.54B-381

."

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 the special tool. Refer to "How to connect SWS 

monitor 

P.54B-13

."

(2) Operate scan tool MB991958 according to the procedure 

below to display "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."

(3) Check 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 N-2 "ETACS-ECU 

does not receive any signal from the hazard warning 
light switch 

P.54B-523

."

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-390

INSPECTION PROCEDURE I-3: Flasher Timer: One of the turn-signal lights does not illuminate.

JUNCTION BLOCK

BATTERY

RELAY
BOX

FRONT
COMBINATION
LIGHT

REAR
COMBINATION
LIGHT

(LH)

(RH)

(LH)

(RH)

TURN-SIGNAL
LIGHT RELAY: LH

TURN-SIGNAL
LIGHT RELAY: RH

ETACS-ECU

JUNCTION BLOCK SIDE

Turn-Signal Lights Circuit