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

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)

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

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

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)

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