Mitsubishi Galant 9G. Manual - part 1468

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-282

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 ).

STEP 3. Check the seat slide sensor. (Using scan tool 
MB991958, read the diagnostic trouble code.)
(1) Disconnect the negative battery terminal.
(2) Disconnect the seat slide sensor connector D-27.

(3) Connect special tool MB991865 to special tool MB991866.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly, as the connector contact pressure may be 
weakened.
(4) Insert special tool MB991866 into the D-27 harness side 

connector by backprobing.

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

diagnostic trouble code. 

Q: Is DTC B1506 set?

YES : Go to Step 4.
NO :  Replace the seat slide sensor (Refer to 

P.52B-384

). 

Then go to Step 5.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC308165

CONNECTOR : D-27

AC

D-27 (GR)

HARNESS SIDE

AC006042BQ

MB991866
(RESISTOR HARNESS)

D-27 HARNESS SIDE
CONNECTOR

D-27 SEAT SLIDE
SENSOR CONNECTOR

MB991865 (DUMMY 
RESISTOR: 3

 

Ω

)

(REAR VIEW)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-283

STEP 4. Check the harness for open circuit between 
SRS-ECU connector C-122 (terminal No.1 and 2) and the 
seat slide sensor connector D-27 (terminal No.1 and 2).
(1) Disconnect SRS-ECU connector C-122 and 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.
(2) Check for continuity between the following terminals. It 

should be less than 2 ohms.

• SRS-ECU connector C-122 (terminal No.2) and the seat 

slide sensor connector D-27 (terminal No.1)

• SRS-ECU connector C-122 (terminal No.1) and the seat 

slide sensor connector D-27 (terminal No.2)

Q: Does continuity exist?

YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC B1506 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-122 and seat slide sensor connector 
D-27. Then 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

AC308165

CONNECTOR : D-27

AC

D-27 (GR)

HARNESS SIDE

AC308186

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)

D-27 HARNESS SIDE
CONNECTOR (REAR VIEW)

AB

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-284

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 B1506 set?

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

DTC B1507: Seat Slide Sensor System Fault Ground Circuit (Short-Circuited to Ground)

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

  Seat Slide Sensor Circuit

SEAT SLIDE
SENSOR

HALL IC

SEAT SLIDE SENSOR
DETECTION CIRCUIT

SRS-ECU

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-285

CAUTION

If DTC B1507 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 ground in the seat slide sensor harness

• 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)

• MB991865: Dummy resistor

• MB991866: Resister harness

AC305362

CONNECTOR: C-122

C-122 (Y)

AE

SRS-ECU

AC308165

CONNECTOR : D-27

AB

D-27 (GR)