Mitsubishi Galant 9G. Manual - part 1447

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-198

STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "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

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-199

STEP 3. Check the passenger's seat belt pre-tensioner. 
(Using scan tool MB991958, read the diagnostic trouble 
code.)
(1) Disconnect the negative battery terminal.
(2) Disconnect passenger's seat belt pre-tensioner connector 

D-33. Use a flat-tipped screwdriver to unlock the locking 
button at the harness side connector by withdrawing it 
toward you in two stages, and then disconnect the 
connector.

(3) Connect special tool MB991865 to special tool MB991884.
(4) Connect special tool MB991884 to the D-33 harness side 

connector.

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

diagnostic trouble code.

Q: Is DTC B1462 set?

YES : Go to Step 4.
NO :  Replace the passenger's seat belt pre-tensioner 

(Refer to 

P.52B-380

). Then go to Step 6.

AC307915 AC

CONNECTOR: D-33

D-33 (B)

FORWARD

CENTER 
PILLAR

HARNESS SIDE
CONNECTOR
(FRONT VIEW)

2 1

AC103556AU

LOCKING BUTTON

FLAT-TIP SCREW
DRIVER

D-33 HARNESS 
SIDE CONNECTOR

D-33 PASSENGER'S 
SEAT BELT
PRE-TENSIONER
CONNECTOR

MB991884
MB991885

AC103283AP

MB991865
(DUMMY RESISTOR : 3

Ω

)

MB991884
(RESISTOR 
HARNESS)

D-33  HARNESS SIDE 
CONNECTOR

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-200

STEP 4. Check the passenger's seat belt pre-tensioner 
circuit. Measure the voltage at the SRS-ECU connector 
C-120.
(1) Disconnect SRS-ECU connector C-120.

(2) Disconnect passenger's seat belt pre-tensioner connector 

D-33. Use a flat-tipped screwdriver to unlock the locking 
button at the harness side connector by withdrawing it 
toward you in two stages, and then disconnect the 
connector.

(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-120 harness side 

connector terminals 59, 60 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 B1462 sets, 
replace the SRS-ECU (Refer to 

P.52B-365

). Then go 

to Step 6.

NO :  Go to Step 5.

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)

AC307915 AC

CONNECTOR: D-33

D-33 (B)

FORWARD

CENTER 
PILLAR

HARNESS SIDE
CONNECTOR
(FRONT VIEW)

2 1

AC103556AU

LOCKING BUTTON

FLAT-TIP SCREW
DRIVER

D-33 HARNESS 
SIDE CONNECTOR

D-33 PASSENGER'S 
SEAT BELT
PRE-TENSIONER
CONNECTOR

AC301577

63

55

51

69

61

66

58

65

64

56 57

68

60

67

59

70

62

53

52 B

A

54

AD

C-120 HARNESS SIDE
CONNECTOR
(REAR VIEW)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-201

STEP 5. Check the harness wires for short circuit to power 
supply between SRS-ECU connector C-120 (terminal No.59 
and 60) and passenger's seat belt pre-tensioner connector 
D-33 (terminal No.1 and 2).
Q: Are the harness wires between SRS-ECU connector 

C-120 (terminal No.59 and 60) and passenger's seat belt 
pre-tensioner connector D-33 (terminal No.1 and 2) in 
good condition?
YES : Go to Step 6.
NO :  Replace the harness wires between SRS-ECU 

connector C-120 and passenger's seat belt 
pre-tensioner connector D-33. 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 B1462 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)

AC307915 AC

CONNECTOR: D-33

D-33 (B)

FORWARD

CENTER 
PILLAR

HARNESS SIDE
CONNECTOR
(FRONT VIEW)

2 1

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827