Mitsubishi Galant (2004+). Manual — part 322

SYMPTOM PROCEDURES

TSB Revision

SIMPLIFIED WIRING SYSTEM (SWS)

54B-479

INSPECTION PROCEDURE K-7: Interior Light: The seat belt warning light 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 and the ETACS-ECU illumi-
nates and flashes the seat belt warning light by using
the signal from the seat belt switch, the ignition
switch (IG1) and the vehicle speed signal.

.

TECHNICAL DESCRIPTION (COMMENT)
If the seat belt warning light does not illuminate or
flash correctly, connector(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

·IGNITION SWITCH (IG1)
·SEAT BELT SWITCH
·VEHICLES SPEED
SIGNAL

COMBINATION
METER

ETACS-ECU

INPUT SIGNAL

CAN COMMUNICATION LINE
(CAN_H_LINE)

CAN COMMUNICATION LINE
(CAN_L_LINE)

Seat Belt Warning Light Circuit

SYMPTOM PROCEDURES

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-480

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-481

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-482

STEP 4. Check the input signal by using "DATA LIST"
menu of the SWS monitor.

Check the input signals from the following switches:

• Ignition switch: ON

(1) Operate scan tool MB991958 according to the procedure

below to display "ETACS ECU."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Data List."
f. Select "ETACS ECU."

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

described in the table below.

Q: Is the scan tool MB991958 display the items "IG SW

(IG1)" normal condition?
YES : Go to Step 5.
NO : Refer to Inspection Procedure M-2 "ETACS-ECU

does not receive any signal from the ignition switch
(IG1)

P.54B-490

."

STEP 5. Replace the combination meter.
(1) Replace the combination meter.
(2) Check that the seat belt warning light illuminates normally.
Q: Is the seat belt warning light in good condition?

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

warning light illuminates normally.

ITEM NO.

ITEM NAME

NORMAL CONDITION

ITEM 30

IG SW (IG1)

ON

AC305411AB

MB991910

DATA LINK

CONNECTOR

MB991827

MB991824

MB991806

MB991812

AC302210

COLUMN SWITCH
CONNECTOR

COLUMN SWITCH
CONNECTOR AT
HARNESS SIDE

MB991812

AB