Mitsubishi Galant (2004+). Manual - part 1612

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-341

INSPECTION PROCEDURE 3: When the Ignition Key is Turned to "ON" (Engine Stopped), the SRS 
Warning Light does not Illuminate. INSPECTION PROCEDURE 4: The SRS Warning Light Remains 
Illuminated after the Engine is Started.

.

TECHNICAL DESCRIPTION (COMMENT)

• The SRS-ECU sends the SRS warning light sig-

nal to the combination meter via the CAN com-
munication.

• This may be caused by faults in the CAN bus line, 

the combination meter or the SRS-ECU.

.

CPU

COMBINATION
METER 

JOINT
CONNECTOR (3)

DATA LINK
CONNECTOR

SRS-ECU

BATTERY

IGNITION SWITCH (IG1)

AC308124

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-342

TROUBLESHOOTING HINTS (The most likely 
causes for this case:) 

• Damaged wiring harness or connector

• Combination meter defect 

• Malfunction of the SRS-ECU

.

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.
Use scan tool MB991958 to diagnose the CAN bus lines.
(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.
Q: Is the check result satisfactory?

YES : Go to Step 2.
NO :  Repair the CAN bus lines (Refer to GROUP 54C, 

Diagnosis-Can Bus Diagnostic Chart 

P.54C-14

). 

Repair the CAN bus lines, and then go to Step 2.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-343

STEP 2. Using scan tool MB991958, read the combination 
meter 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.
Use scan tool MB991958 to check whether combination meter 
DTC U1112 has been set.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check whether combination meter DTC U1112 has been 

set.

Q: Is combination meter DTC U1112 set?

YES : Replace the SRS-ECU. 
NO :  Replace the combination meter.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-344

DATA LIST REFERENCE TABLE

M1524003500038

The following items can be read by the scan tool 
from the ABS-ECU input data.

ACTUATOR TEST REFERENCE TABLE

M1524003600035

The scan tool activates the following actuators for 
testing.

No.

DATA LIST ITEM

CHECK 
CONDITIONS

NORMAL CONDITIONS

01

Failure continuation time 1

Always

Maximum time to be stored: 9999 
minutes (approximately seven 
days)

02

Failure continuation time 2

Always

03

Seat position

Slide the seat from 
the back-end position 
to the front-end 
position.  

Rear/Front

04

Passenger seat Airbag Ignition

Do not apply any load 
to the passenger 
seat.

Permission/Prohibition

06

Driving seatbelt (Buckle SW1)

Wear the driver 
seatbelt.

Unfastened/Fastened

07

Driving seatbelt (Buckle SW2)

Undo the driver 
seatbelt.

Fastened/Unfastened

08

Passenger seatbelt (Buckle 
SW1)

Wear the passenger 
seatbelt.

Unfastened/Fastened

09

Passenger seatbelt (Buckle 
SW2)

Undo the passenger 
seatbelt.

Fastened/Unfastened

10

Elimination times

Always

Maximum time to be stored: 255 
days

42

OCSS Occupant Classification

Apply a load to the 
passenger seat.

Class 0/Class 1/Class 2/Not Clear/

−

44

OCSS Occupant Weight

kg/Unkown

45

OCSS Parts Number

Always

−

MUT-III SCAN TOOL 
DISPLAY

ITEM NO.

ITEM

PARTS TO BE ACTIVATED

SRS Warning Lamp

01

The SRS warning light illuminates.

CAN output

Passenger Seat belt 
Warning Lamp

02

Passenger’s seat belt warning light 
illumination

SRS-ECU output

P/Seat belt Warning 
Lamp Cut Off

03

Passenger’s air bag OFF indicator 
light illumination