Mitsubishi Galant (2004+). Manual - part 308

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-423

INSPECTION PROCEDURE J-4: The fog light indicator does not illuminate normally.

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 fog lights are illuminated, 
the ETACS-ECU sends a signal to illuminate the fog 
light indicator via the CAN bus line.

.

TECHNICAL DESCRIPTION (COMMENT)
If the fog light indicator does not illuminate normally, 
connector(s), wiring harness in the CAN bus lines, 
the ETACS-ECU or the combination meter may be 
defective.

.

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 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

ETACS-
ECU

COMBINATION
METER

FOG LIGHT
SWITCH

CAN COMMUNICATION LINE
(CAN_H LINE)

CAN COMMUNICATION LINE
(CAN_L LINE)

Fog Light Indicator Light Circuit

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-424

STEP 1. Check the fog lights.

When the fog light switch is operated, check that the fog lights 
illuminate/go off normally.
Q: Are the fog lights operating properly?

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

Procedure J-3 "One of the fog lights does not 
illuminate 

P.54B-417

."

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

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-425

STEP 3. Using scan tool MB991958, read the METER 
diagnostic trouble code.

(1) Check whether a combination meter-related DTC is set.
(2) Turn the ignition switch to the "ON" position.

Check whether the combination meter-related DTC is set.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Diagnose the combination meter. Refer to 

P.54A-56

.

NO :  Go to Step 4.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-426

STEP 4. Use scan tool MB991958 to select "ECU COMM 
Check" on the SWS monitor display.

Check the ETACS-ECU.

CAUTION

Connect special tool MB991910 before connecting special 
tool MB991812. Be sure to connect special tool MB991806 
after turning on special tool MB991824.
(1) Connect the SWS monitor. Refer to "How to connect SWS 

monitor 

P.54B-13

."

(2) Turn the ignition switch to the "ON" position.
(3) Operate scan tool MB991958 according to the procedure 

below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."

(4) Scan tool MB991958 should show "OK" on the "ECU 

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

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

YES : Go to Step 5.
NO :  Refer to Inspection Procedure A-3 "Communication 

with the ETACS-ECU is not possible 

P.54B-79

."

STEP 5. Replace the combination meter.
(1) Replace the combination meter.
(2) Check that the fog light indicator light illuminates normally.
Q: Is the fog light indicator light operating properly?

YES : No action is necessary and testing is complete.
NO :  Replace the ETACS-ECU. Check that the fog light 

indicator light illuminates normally.

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH 
CONNECTOR

COLUMN SWITCH 
CONNECTOR AT 
HARNESS SIDE 

MB991812

AB