Mitsubishi Galant 9G. Manual — part 1445

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-190

STEP 9. 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 B1460 set?

YES : Return to Step 1.
NO : The procedure is complete.

DTC B1461: Seat Belt Pre-Tensioner (RH) (Squib) System Fault 2 (Open in the Squib Circuit)

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SEAT BELT
PRE-TENSIONER
(RH)

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

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

PRE-TENSIONER(RH)
DRIVE CIRCUIT

: CONNECTOR CONNECTED: ON
CONNECTOR DICONNECTED: OFF

NOTE

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-191

CAUTION

If DTC B1461 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

• Open circuit in the passenger's seat belt pre-ten-

sioner (squib) circuit

• Improper connector contact

• Malfunction of the SRS-ECU

.

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)

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-192

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 ).

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

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-193

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 B1461 set?

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

(Refer to

P.52B-380

). Then go to Step 5.

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