Mitsubishi Galant 9G. Manual - part 1479

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-326

NOTE: After inspecting intermediate connectors C-22, C-211 
and C-215 inspect the wiring harness. If intermediate connec-
tors C-22, C-211 and C-215 are damaged, repair or replace 
them. Refer to GROUP 00E, Harness Connector Inspection . 
Then go to Step 8.

Q: Are the harness wires between occcupant 

classification-ECU connector D-30 (terminal No.2) and 
ignition switch connector C-308 (terminal No.2) in good 
condition?
YES : Then go to Step 6.
NO :  Replace the harness wires between occupant 

classification-ECU connector D-30 and ignition switch 
connector C-308. Then go to Step 8.

AC305233 AI

CONNECTOR: C-22

C-22 (Y)

AC305416

CONNECTORS: C-211, C-215

JUNCTION BLOCK 
(FRONT VIEW)

C-215

C-211

HARNESS SIDE

C-211

HARNESS SIDE

C-215

AK

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-327

STEP 6. Check the harness wires for open circuit or short 
circuit between SRS-ECU connector C-120 (terminal No.66) 
and occupant classification-ECU connector D-30 (terminal 
No.3).
Q: Are the harness wires between SRS-ECU connector 

C-120 (terminal No.66) and occupant classification-ECU 
connector D-30 (terminal No.3) in good condition?
YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC B1545 or B1546 
sets, replace the front seat slide adjuster (Refer to 
GROUP 52A, Front seat assembly 

P.52A-20

). Then 

go to Step 7.

NO :  Replace the harness wires between SRS-ECU 

connector C-120 and occupant classification-ECU 
connector D-30. Then go to Step 8.

STEP 7. 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 B1545 or B1546 set?

YES : Replace the SRS-ECU (Refer to 

P.52B-365

). Then go 

to Step 8.

NO :  The procedure is complete.

AC305362

CONNECTOR: C-120

C-120 (Y)

AG

SRS-ECU

63

55

51

69

61

66

58

65

64

56 57

68

60

67

59

70

62

53

52 B

A

54

C-120 
Harness side
connector 
(rear view)

AC308166

CONNECTOR : D-30

AC

D-30 (GR)

HARNESS SIDE

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-328

STEP 8. 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 B1545 or B1546 set?

YES : Return to Step 1.
NO :  The procedure is complete.

DTC B1547: Passenger’s Front Air Bag Cut Off System

CAUTION

If DTC B1547 is set in the SRS-ECU, always diag-
nose the CAN main bus line.

.

DTC SET CONDITIONS

This DTC is set if the following conditions are 
detected:

• Malfunction of occupant classification-ECU sys-

tem

• Malfunction of front passenger’s seat belt switch 

system

• Malfunction of front passenger’s air bag module 

system

• Malfunction of SRS-ECU system

.

TROUBLESHOOTING HINTS

Malfunction of 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)

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-329

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 ).

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 Use Troubleshooting/Inspection 
Service Points 

− How to Cope with Intermittent 

Malfunctions ).

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827