Mitsubishi Galant 9G. Manual - part 1444

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-186

STEP 4. Check the SRS-ECU connector C-120.
Q: Is connector correctly engaged?

YES : Go to Step 5.
NO :  Engage the connector correctly. Then go to Step 9.

STEP 5. Check SRS-ECU connector C-120 and passenger’s 
seat belt pre-tensioner connector D-33. (Using scan tool 
MB991958, read the diagnostic trouble code.)
(1) Disconnect the negative battery terminal.
(2) Disconnect connectors C-120 and D-33, and then 

reconnect them. For 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) Connector the negative battery terminal.
(4) Erase the diagnostic trouble code memory, and check the 

diagnostic trouble code.

Q: Is DTC B1460 set?

YES : Go to Step 6.
NO :  The procedure is complete. It is assumed that DTC 

B1460 set because connector C-120 or D-33 was 
engaged improperly.

AC305362

CONNECTOR: C-120

C-120 (Y)

AG

SRS-ECU

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51

69

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58

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52 B

A

54

C-120 
Harness side
connector 
(rear view)

AC305362

CONNECTOR: C-120

C-120 (Y)

AG

SRS-ECU

63

55

51

69

61

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58

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56 57

68

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59

70

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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

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-187

STEP 6. 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 B1460 set?

YES : Go to Step 7.
NO :  Replace the passenger's seat belt pre-tensioner 

(Refer to 

P.52B-380

). Then go to Step 9. 

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-188

STEP 7. Check the passenger's seat belt pre-tensioner 
circuit. Measure the resistance at the SRS-ECU connector 
C-120.
(1) Disconnect SRS-ECU connector C-120.

DANGER

To prevent the seat belt pre-tensioner from deploying 
unintentionally, disconnect the passenger’s seat belt 
pre-tensioner connector D-33 to short the squib cir-
cuit.

(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.

CAUTION

Insert an insulator such as a cable tie to a depth of 4mm 
(0.16 inch) or more, otherwise the short spring will not be 
released.
(3) Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) 

thick] between terminals 59, 60 and the short spring to 
release the short spring.

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

AC301608

SEC-
TION
A - A

C-120 HARNESS SIDE 
CONNECTOR (FRONT VIEW)

CABLE TIE

SHORT SPRING

4 mm OR MORE

TERMINAL

A

AE

A

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-189

CAUTION

Do not insert a test probe into the terminal from its front 
side directly as the connector contact pressure may be 
weakened.
(4) Check for continuity between C-120 harness side connector 

terminals 59 and 60.
It should be open circuit.

Q: Does continuity exist?

YES : Go to Step 8.
NO :  Erase the diagnostic trouble code memory, and check 

diagnostic trouble code. If DTC B1460 set, replace 
the SRS-ECU (Refer to 

P.52B-365

). Then go to Step 

9.

STEP 8. Check the harness for short circuit 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 harness wires between SRS-ECU connector C-120 

(terminal No.59 and 60) connector and passenger’s seat 
belt pre-tensioner connector (terminal No.1 and 2) in 
good condition?
YES : Go to Step 9.
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 9.

AC301572

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51

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56 57

68

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67

59

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62

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52 B

A

54

C-120 HARNESS SIDE
CONNECTOR (REAR VIEW)

AE

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