Mitsubishi Galant (2004+). Manual — part 1562

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-141

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 Cope with Intermittent
Malfunction

P.00-6

).

STEP 3. Check the side-airbag module (RH). (Using scan
tool MB991958, read the diagnostic trouble code.)
(1) Disconnect the negative battery terminal.

(2) Disconnect the side-airbag module (RH) connector D-32.

(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-32 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 B1423 set?

YES : Go to Step 4.
NO : Replace the seatback frame of the front seat (RH).

(Refer to GROUP 52A, Front Seat

P.52A-26

). Then

go to Step 6.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC307779

D-32 (R)

AD

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

CONNECTOR : D-32

AC006042BO

MB991866
(RESISTOR HARNESS)

D-32 HARNESS SIDE
CONNECTOR

D-32 SIDE-AIRBAG
MODULE (RH) CONNECTOR

MB991865 (DUMMY
RESISTOR: 3

Ω)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-142

STEP 4. Check the side-airbag module (RH) circuit.
Measure the resistance at the SRS-ECU connector C-120.

(1) Disconnect SRS-ECU connector C-120.

DANGER

To prevent the air bag from deploying unintentionally,
disconnect the side-airbag module (RH) connector
D-32 to short the squib circuit.

(2) Disconnect side-airbag module (RH) connector D-32.

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-120 harness side connector

terminals 57, 58 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 B1423 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)

AC307779

D-32 (R)

AD

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

CONNECTOR : D-32

AC301576

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)

AC

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-143

STEP 5. Check the harness wires for short circuit to
ground between SRS-ECU connector C-120 (terminal
No.57 and 58) and side-airbag module (RH) connector D-32
(terminal No.1 and 2).

Q: Are the harness wires between SRS-ECU connector

C-120 (terminal No.57 and 58) and side-airbag module
(RH) connector D-32 (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 side-airbag module (RH)
connector D-32. 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 B1423 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)

AC307779

D-32 (R)

AD

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

CONNECTOR : D-32

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-144

DTC B1426: Side Impact Sensor (RH) System for Fault 1
DTC B1436: Side Impact Sensor (LH) System for Fault 1

CAUTION

If DTC B1426 or B1436 is set in the SRS-ECU,
always diagnose the CAN main bus line.

.

DTC SET CONDITIONS
These DTCs are set if the following conditions are
detected from the analog G-sensor inside the side
impact sensor output:

• Analog G-sensor is not operating.

• Analog G-sensor characteristics are abnormal.

• Analog G-sensor output is abnormal.

.

TROUBLESHOOTING HINTS
Malfunction of side impact sensor (RH) (for DTC
B1426) and side impact sensor (LH) (for DTC
B1436)

.

DIAGNOSIS

Required Special Tool:

• 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)

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