Mitsubishi Galant (2004+). Manual - part 1569

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-169

STEP 4. Check the side-airbag module (RH) circuit. 
Measure the voltage at the SRS-ECU connector C-122.

(1) Disconnect SRS-ECU connector C-122.

DANGER

To prevent the air bag from deploying unintentionally, 
disconnect the side-airbag module (LH) connector 
D-24 to short the squib circuit.

(2) Disconnect left hand side-airbag module (LH) connector 

D-24.

(3) Turn the ignition switch to the "ON" position.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly, as the connector contact pressure may be 
weakened.
(4) Measure the voltage between C-122 harness side 

connector terminals 9, 10 and body ground.
Voltage should measure 0 volt.

Q: Is the measured voltage within the specified range? 

YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC B1432 sets, 
replace the SRS-ECU. (Refer to 

P.52B-365

). Then go 

to Step 6.

NO :  Go to Step 5. 

AC305362

CONNECTOR: C-122

C-122 (Y)

AI

SRS-ECU

C-122 
Harness side
connector 
(rear view)

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

AC307778

CONNECTOR : D-24

AC

D-24 (R)

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC308177

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

C-122 HARNESS SIDE
CONNECTOR
(REAR VIEW)

AB 

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-170

STEP 5. Check the harness wires for short circuit to power 
supply between SRS-ECU connector C-122 (terminal No.9 
and 10) and side-airbag module (LH) connector D-24 
(terminal No.1 and 2). 

Q: Are the harness wires between SRS-ECU connector 

C-122 (terminal No.9 and 10) and side-airbag module 
(LH) connector D-24 (terminal No.1 and 2) in good 
condition?
YES : Go to Step 6.
NO :  Replace the harness wires between SRS-ECU 

connector C-122 and side-airbag module (LH) 
connector D-24. Then go to Step 6.

STEP 6. 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 B1432 set?

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

AC305362

CONNECTOR: C-122

C-122 (Y)

AI

SRS-ECU

C-122 
Harness side
connector 
(rear view)

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

AC307778

CONNECTOR : D-24

AC

D-24 (R)

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC206894

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-171

DTC B1433: Side-Airbag Module (LH)  (Squib) System Fault Ground Circuit (Short-Circuited to 
Ground)

CAUTION

If DTC B1433 is set in the combination meter, 
always diagnose the CAN bus lines.

.

CIRCUIT OPERATION

• The SRS-ECU judges how severe a collision is 

by detecting signals from the left and right side 
impact sensors. If the impact is over a predeter-
mined level, the SRS-ECU sends an ignition sig-
nal. At this time, if the side-airbag safing 
G-sensor is on, the SRS side-airbag will inflate.

• The ignition signal is input to the side-airbag 

module to inflate the side-airbag.

.

DTC SET CONDITIONS
This DTC is set if there is abnormal resistance 
between the input terminals of the side-airbag mod-
ule (LH) (squib).

.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors

• Short to ground in the left hand side-airbag mod-

ule (squib) harness

• Malfunction of the SRS-ECU

.

SIDE AIR BAG
MODULE
(SQUIB) (LH)

AIR BAG DRIVE CIRCUIT

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

Side-Airbag Module (LH) (Squib) Circuit

NOTE
  : CONNECTOR
    CONNECTED
    : ON
    CONNECTOR
    DISCONNECTED
    : OFF

AC305362

CONNECTOR: C-122

C-122 (Y)

AE

SRS-ECU

AC307778

CONNECTOR : D-24

AB

D-24 (R)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-172

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)

• MB991865: Dummy resistor

• MB991866: Resister harness

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 "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
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

). .

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827