Mitsubishi Galant (2004+). Manual - part 1564

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-149

STEP 4. Check the harness wires for open circuit or short 
circuit between SRS-ECU connector C-120 (terminal No.63 
and 64) and side impact sensor (RH) connector D-35 
(terminal No.1 and 2).

Q: Are the harness wires between SRS-ECU connector 

C-120 (terminal No.63 and 64) and side impact sensor 
(RH) connector D-35 (terminal No.1 and 2) in good 
condition?
YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC B1427 sets, 
replace the SRS-ECU (Refer to 

P.52B-365

). Then go 

to Step 5.

NO :  Replace the harness wires between SRS-ECU 

connector C-120 and side impact sensor (RH) 
connector D-35. Then go to Step 5.

STEP 5. 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 B1427 set?

YES : Return to Step 1.
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)

AC308163

CONNECTOR: D-35

AC

FRONT SEAT BELT

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-150

DTC B1428: Side-Impact sensor (RH) (Squib) for Power Supply Circuit
DTC B1429: Side-Impact sensor (RH) (Squib) for Communication System

CAUTION

If DTC B1428 or B1429 is set in the SRS-ECU, 
always diagnose the CAN main bus line.

.

CIRCUIT OPERATION
The side impact sensor includes an analog G sensor 
and CPU, etc. The CPU monitors the analog G sen-
sor output signal. If the CPU judges that the 
side-airbags should be deployed, it sends a fire sig-
nal to the SRS-ECU to deploy the side-airbags. In 
addition, the CPU diagnoses the internal compo-
nents of the side impact sensor. If a malfunction 
occurs, it requests the SRS-ECU to set a diagnostic 
trouble code.

.

DTC SET CONDITIONS
These DTCs are set if communication between the 
side impact sensor (RH) and the SRS-ECU is not 
possible or communication is faulty.

.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors

• Malfunction of the side impact sensor (RH)

• Malfunction of the SRS-ECU

.

SIDE IMPACT 
SENSOR (RH)

INTERFACE 
CIRCUIT

SRS-ECU

Side Impact Sensor (RH) Circuit

AC305362

CONNECTOR: C-120

C-120 (Y)

AC

SRS-ECU

AC308163

CONNECTOR: D-35

AB

FRONT SEAT BELT

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-151

DIAGNOSIS

Required Special Tool:

• 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-152

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 any diagnostic trouble code. (Using scan 
tool MB991958, read the diagnostic trouble code.)

Check the side impact sensor (RH).
(1) Disconnect the negative battery terminal.
(2) Temporaily replace the side impact sensor (RH) with the 

side impact sensor (LH).

(3) Connect the negative battery terminal.
(4) Erase diagnostic trouble code memory, and check the 

diagnostic trouble code.

Q: Is DTC B1438 or B1439 set?

YES : Replace the side impact sensor (RH) with a new one. 

(Refer to 

P.52B-377

). Then go to Step 5.

NO :  Go to Step 4.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827