Mitsubishi Galant (2004+). Manual — part 321

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-475

INSPECTION PROCEDURE K-6: Interior Light: The door ajar indicator lights do not illuminate or go
out 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
The combination meter receives the door switches
signals from the ETACS-ECU, and then controls the
door ajar indicator, based on these signals.

.

TECHNICAL DESCRIPTION (COMMENT)
If the door ajar indicator does not illuminate, connec-
tor(s), wiring harness in the CAN bus lines, the door
switches, 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

ALL DOOR

SWITCHES

INPUT SIGNAL

ETACS-
ECU

COMBINATION
METER

CAN COMMUNICATION LINE
(CAN_L LINE)

CAN COMMUNICATION LINE
(CAN_H LINE)

Door Ajar Indicator Light Circuit

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

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STEP 1. 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 2.
NO : Repair the CAN bus line (Refer to GROUP 54C,

Diagnosis

P.54C-14

).

STEP 2. Using scan tool MB991958, read the diagnostic
trouble code related to the combination meter.

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

(3) Check whether the combination meter-related DTC is set.
(4) 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 3.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-477

STEP 3. 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 "LOCK" (OFF) 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 4.
NO : Refer to Inspection Procedure A-3 "Communication

with the ETACS-ECU is not possible

P.54B-79

."

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH
CONNECTOR

COLUMN SWITCH
CONNECTOR AT
HARNESS SIDE

MB991812

AB

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-478

STEP 4. Check the input signal (by using the pulse check
mode of the monitor).

Check the following switches and input signals:

• Door switches

(1) 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."

(2) Check if scan tool MB991958 sounds or not.

Q: When any door switch is operated, does scan tool

MB991958 sound?
YES : Go to Step 5.
NO : Refer to Inspection Procedure N-3 "ETACS-ECU

does not receive any signal from any of the door
switches

P.54B-527

."

STEP 5. Replace the combination meter.
(1) Replace the combination meter.
(2) Check that the door ajar indicator light illuminates normally.
Q: Is the door ajar indicator light in good condition?

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

indicator light illuminates normally.

ITEM NAME

CONDITION

door switches

Open or close one of the doors

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827