Mitsubishi Galant 9G. Manual - part 1443

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-182

STEP 4. Check the harness wires for open circuit or short
circuit between SRS-ECU connector C-122 (terminal No.19
and 20) and side impact sensor (LH) connector D-20
(terminal No.1 and 2).
Q: Are the harness wires between SRS-ECU connector

C-122 (terminal No.19 and 20) and side impact sensor
(LH) connector D-20 (terminal No.1 and 2) in good
condition?
YES : Erase the diagnostic trouble code memory, and check

the diagnostic trouble code. If DTC B1438 or B1439
sets, replace the SRS-ECU (Refer to

P.52B-365

Then go to Step 5.

NO : Replace the harness wires between SRS-ECU

connector C-122 and side impact sensor (LH)
connector D-20. Then go to Step 5.

STEP 5. 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 B1438 or B1439 set?

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

AC305362

CONNECTOR: C-122

C-122 (Y)

SRS-ECU

C-122
Harness side
connector
(rear view)

1 2

3 4

AC305250

CONNECTOR: D-20

FRONT SEAT BELT

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-183

DTC B1460: Seat Belt Pre-Tensioner (RH) (Squib) System Fault 1 (Short Circuit between Terminals of
the Squib Circuit)

CAUTION

If DTC B1460 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

• Improper engaged connector or defective short

spring*

• Short circuit between the passenger's seat belt

pre-tensioner (squib) circuit terminals

• Damaged connector(s)

• Malfunction of the SRS-ECU

SEAT BELT
PRE-TENSIONER
(RH)

SRS-ECU

CONNECTOR
LOCK SWITCH

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

PRE-TENSIONER(RH)
DRIVE CIRCUIT

: CONNECTOR CONNECTED: ON
CONNECTOR DICONNECTED: OFF

NOTE

AC305362

CONNECTOR: C-120

C-120 (Y)

SRS-ECU

AC307915 AB

CONNECTOR: D-33

D-33 (B)

FORWARD

CENTER
PILLAR

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-184

NOTE: *: The squib circuit connectors integrate a
"short" spring (which prevents the seat belt pre-ten-
sioner from deploying unintentionally due to static
electricity by shorting the positive wire to the ground
wire in the squib circuit when the connectors are dis-
connected) (Refer to

P.52B-3

). Therefore, if connec-

tor C-120 or D-33 is damaged or improperly
engaged, the short spring may not be released when
the connector is connected.

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 ).

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-185

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 ).

STEP 3. Using scan tool MB991958, read the diagnostic
trouble code.

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) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOOK (OFF)" position.

Q: Is DTC B1519 set?

YES : Go to Step 4.
NO : Go to Step 5.

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC206894

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

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