Mitsubishi Galant (2004+). Manual - part 294

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-367

STEP 20. Check headlight (HIGH: RH) connector A-31 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector.

Q: Is headlight (HIGH: RH) connector A-31 in good 

condition?
YES : Go to Step 21.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. Check that the headlight (HIGH: RH) 

illuminates normally.

STEP 21. Check the headlight bulb (HIGH: RH).
(1) Remove the headlight bulb (HIGH: RH).
(2) Verify that the headlight bulb (HIGH: RH) is not damaged or 

burned out.

Q: Is the headlight bulb (HIGH: RH) in good condition?

YES : Go to Step 22.
NO :  Replace the headlight bulb (HIGH: RH). Verify that the 

headlight (HIGH: RH) illuminates normally.

STEP 22. Check the ground circuit to the headlight (HIGH: 
RH). Measure the resistance at headlight (HIGH: RH) 
connector A-31.

(1) Disconnect headlight (HIGH: RH) connector A-31 and 

measure the resistance available at the wiring harness side 

of the connector.

(2) Measure the resistance value between terminal 2 and 

ground.

• The resistance should be 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES : Go to Step 24.
NO :  Go to Step 23.

AC305206AU

CONNECTOR: A-31

A-31 (B)

HARNESS SIDE

AC305206AU

CONNECTOR: A-31

A-31 (B)

HARNESS SIDE

AC209364GS

CONNECTOR A-31
(HARNESS SIDE)

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-368

STEP 23. Check the wiring harness between headlight 
(HIGH: RH) connector A-31 (terminal 2) and ground.

Q: Is the wiring harness between headlight (HIGH: RH) 

connector A-31 (terminal 2) and ground in good 
condition?
YES : Replace the headlight socket (HIGH: RH). Verify that 

the headlight (HIGH: RH) illuminates normally.

NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary. Verify that 
the headlight (HIGH: RH) illuminates normally.

STEP 24. Check front-ECU connector A-11X for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.

Q: Is front-ECU connector A-11X in good condition?

YES : Go to Step 25.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. Check that the headlight (HIGH: RH) 

illuminates normally.

STEP 25. Check the wiring harness between headlight 
(LOW: RH) connector A-32 (terminal 1) and front-ECU 
connector A-11X (terminal 10).

Q: Is the wiring harness between headlight (LOW: RH) 

connector A-32 (terminal 1) and front-ECU connector 
A-11X (terminal 10) in good condition?
YES : No action is necessary and testing is complete.
NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary. Verify that 
the headlight (HIGH: RH) illuminates normally.

AC305206AU

CONNECTOR: A-31

A-31 (B)

HARNESS SIDE

AC305977AH

CONNECTOR: A-11X

RELAY BOX SIDE 

AC305977AH

CONNECTOR: A-11X

RELAY BOX SIDE 

AC305206

A-32 (BR)

HARNESS SIDE

CONNECTOR: A-32

AO

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-369

INSPECTION PROCEDURE H-8: Headlight and Taillight: The High-beam indicator light does not 
illuminate.

NOTE: This troubleshooting procedure requires the 
use of scan tool MB991958 and SWS monitor kit 
MB991813. For details on how to use the SWS mon-
itor, refer to "How to use SWS monitor 

P.54B-15

."

.

CIRCUIT OPERATION
At the same time that the high beams are illumi-
nated, the ETACS-ECU sends a signal to illuminate 
the high beam indicator via the CAN bus line.

.

TECHNICAL DESCRIPTION (COMMENT)
If the high beam indicator does not illuminate nor-
mally, connector(s), wiring harness in the CAN bus 
lines, the ETACS-ECU or the combination meter may 
be defective.

.

TROUBLESHOOTING HINTS

• The wiring harness or connectors may have 

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

• The combination meter may be defective

• The ETACS-ECU may be defective

.

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

• MB991813: SWS Monitor Kit

• MB991806: SWS Monitor Cartridge

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

• MB991822: Probe Harness

INPUT SIGNAL

ETACS-
ECU

DIMMER SWITCH

COMBINATION
METER

CAN COMMUNICATION LINE
(CAN_L LINE)

CAN COMMUNICATION LINE
(CAN_H LINE)

High-Beam Indicator Light Circuit

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-370

STEP 1. Check the headlights.

When the lighting switch is operated, check that the headlights 
illuminate/go off normally.
Q: Are the headlights in good condition?

YES : Go to Step 2.
NO :  First, repair the headlights. Refer to Inspection 

Procedure H-7 "One of the headlights does not 
illuminate <2-bulb type>

P.54B-350

 " or "One of the 

headlights does not illuminate <4-bulb 
type>

P.54B-359

 ."

STEP 2. Using scan tool MB991958, diagnose the CAN bus 
line.

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 MB991958.Refer to "How to connect 

SWS monitor 

P.54B-13

."

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 3.
NO :  Repair the CAN bus line (Refer to GROUP 54C, 

Diagnosis 

P.54C-14

).

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827