Mitsubishi Galant (2004+). Manual - part 1599

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-289

STEP 4. Check the seat slide sensor circuit. Measure the 
resistance at the SRS-ECU connector C-122.

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

(2) Disconnect seat slide sensor connector D-27.

CAUTION

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

terminals 1, 2 and body ground.
It should be open circuit.

Q: Does continuity exist?

YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC B1507 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)

AE

SRS-ECU

AC308165

CONNECTOR : D-27

AC

D-27 (GR)

HARNESS SIDE

AC308188

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-290

STEP 5. Check the harness wires for short circuit to 
ground between SRS-ECU connector C-122 (terminal No.2 
and 1) and seat slide sensor connector D-27 (terminal No.1 
and 2).

Q: Are the harness wires between SRS-ECU connector 

C-122 (terminal No.2 and 1) and seat slide sensor 
connector D-27 (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 seat slide sensor connector 
D-27. 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 B1507 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

AC308165

CONNECTOR : D-27

AC

D-27 (GR)

HARNESS SIDE

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-291

DTC B1508: Seat Slide Sensor System Fault Power Supply Circuit (Short-Circuited to Power Supply)

CAUTION

If DTC B1508 is set in the combination meter, 
always diagnose the CAN bus lines.

.

CIRCUIT OPERATION

• The seat slide sensor sets the current value Hi or 

Low determined by the seat position.

• The SRS-ECU determines the seat position 

according to the current value from the seat slide 
sensor.

.

DTC SET CONDITIONS
This DTC is set if there is abnormal resistance 
between the input terminals of the seat slide sensor.

.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors

• Short to the power supply in the seat slide sensor 

harness

• Malfunction of the SRS-ECU

.

SEAT SLIDE
SENSOR

HALL IC

SEAT SLIDE SENSOR
DETECTION CIRCUIT

SRS-ECU

Seat Slide Sensor Circuit

AC305362

CONNECTOR: C-122

C-122 (Y)

AE

SRS-ECU

AC308165

CONNECTOR : D-27

AB

D-27 (GR)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-292

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 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