Mitsubishi Galant (2004+). Manual - part 1609

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-329

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

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.
Check that the DTC except B1547 is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOOK (OFF)" position.
Q: Is the DTC set?

YES : Carry out the troubleshooting according to a set DTC. 

Refer to 

P.52B-33

.

NO :  Go to Step 4 .

STEP 4. Recheck for diagnostic trouble code.

Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.

(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC B1547 set?

YES : Replace the SRS-ECU (Refer to 

P.52B-365

).

NO :  The procedure is complete.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-330

DTC B1556: Seat Slide Sensor System for Fault 2 (Mulfunction of Seat Slide Sensor)

CAUTION

If DTC B1556 is set in the SRS-ECU, always diag-
nose the CAN main bus line.

.

DTC SET CONDITIONS
These DTCs are set if the following conditions are 
detected from the seat slide sensor output:

• Seat slide sensor is not operating.

• Seat slide sensor characteristics are abnormal.

• Seat slide sensor output is abnormal.

.

TROUBLESHOOTING HINTS
Malfunction of seat slide sensor

.

DIAGNOSIS

Required Special Tools:

• 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 (Vehicles with CAN 

communication system)

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 the 

scan tool 

P.52B-30

."

(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

).

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-331

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Go to Step 3.
NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Cope with Intermittent 
Malfunction 

P.00-6

).

STEP 3. Check the seat slide sensor. (Using scan tool 
MB991958, read the diagnostic trouble code.)

Replace seat slide sensor (Refer to 

P.52B-384

).

Check the diagnostic trouble code.
Q: Is either DTC B1556 set?

YES : Replace the SRS-ECU (Refer to 

P.52B-365

).

NO :  The procedure is complete.

DTC U1073: Bus Off

CAUTION

If DTC U1073 is set in the SRS-ECU, diagnose the 
CAN main bus line.

CAUTION

Whenever the ECU is replaced, ensure that the 
communication circuit is normal.

.

TROUBLE JUDGMENT
DTC U1073 will be stored when the SRS-ECU 
ceases CAN communication (bus off) and then 
resumes the communication when the ignition switch 
is turned to the "LOCK" (OFF) position.

.

TECHNICAL DESCRIPTION (COMMENT) 
The wiring harness wire or connectors may have 
loose, corroded, or damage terminals, or terminals 
pushed back in the connector, or the SRS-ECU may 
be defective.

.

TROUBLESHOOTING HINTS

• Defective connector(s) or wiring harness

• Malfunction of the SRS-ECU

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-332

DIAGNOSIS

Required Special Tools:

•  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 (Vehicles with CAN 

communication system)

STEP 1. Using scan tool MB991958, diagnose the CAN bus 
line.

CAUTION

To prevent damage to scan tool (MUT-III), always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool (MUT-III).

1. Connect scan tool MB991958 to the data link connector.
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 lines (Refer to GROUP 54C, 

precautions on how to repair the can bus lines 

P.54C-5

).

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827