Mitsubishi Galant (2004+). Manual - part 1576

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-197

DTC B1462: Seat Belt Pre-Tensioner (RH) (Squib) System Fault for Power Supply Circuit 
(Short-Circuited to Power Supply)

CAUTION

If DTC B1462 is set in the SRS-ECU, always diag-
nose the CAN main bus line.

.

CIRCUIT OPERATION
The SRS-ECU judges how severe a collision is by 
detecting signals from the front impact sensors and 
the front air bag analog G-sensor. If the impact is 
over a predetermined level, the SRS-ECU sends an 
ignition signal. At this time, if the front air bag safing 
G-sensor is on, the pre-tensioner will deploy. 

.

DTC SET CONDITIONS
This DTC is set if there is abnormal resistance 
between the input terminals of the passenger's seat 
belt pre-tensioner (squib).

.

TROUBLESHOOTING HITS

• Damaged wiring harnesses or connectors

• Short to the power supply in the passenger's seat 

belt pre-tensioner (squib) harness

• Malfunction of the SRS-ECU

.

SEAT BELT
PRETENSIONER
(RH)

AIR BAG DRIVE CIRCUIT

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

: CONNECTOR CONNECTED: ON

  CONNECTOR DISCONNECTED: OFF

Passenger's (Front) Seat Belt Pre-Tensioner (Squib) Circuit

AC305362

CONNECTOR: C-120

C-120 (Y)

AC

SRS-ECU

AC307915 AB

CONNECTOR: D-33

D-33 (B)

FORWARD

CENTER 
PILLAR

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-198

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

• MB991865: Dummy resistor

• MB991884: Resister harness (For Pre-tensioner)

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

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-199

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

).

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-200

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