Mitsubishi Outlander GS45X. Manual - part 1441

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-259

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.00-15

).

STEP 3. Check SRS-ECU connector C-27 and driver’s seat 
belt pre-tensioner connector D-121. (Using scan tool 
MB991958, read the diagnostic trouble code.)
(1) Disconnect the negative battery terminal.
(2) While pushing the part "A" indicated in the figure of the 

harness side connector, turn the lock lever to the direction 
of the arrow to release the lock lever, and disconnect the 
C-27 SRS-ECU connector. Then connect the connector.

(3) After disconnecting the D-121 harness side connectors, 

connect the connectors again. For the D-121 connector 
disconnection, 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.

(4) Connector the negative battery terminal.
(5) Erase the diagnostic trouble code memory, and check the 

diagnostic trouble code.

Q: Is DTC B1C3B set?

YES : Go to Step 4.
NO :  The procedure is complete. It is assumed that DTC 

B1C3B set because connector C-27 or D-121 was 
engaged improperly.

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link 
connector

AC507645

A

AC

Lock lever

AC507550AE

Seat belt 
pre-tensioner

Harness side
connector

Locking 
button

Flat-tipped
screwdriver

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-260

STEP 4. Check the driver's seat belt pre-tensioner. (Using 
scan tool MB991958, read the diagnostic trouble code.)
(1) Disconnect the negative battery terminal.
(2) While pushing the part "A" indicated in the figure of the 

harness side connector, turn the lock lever to the direction 
of the arrow to release the lock lever, and disconnect the 
C-27 SRS-ECU connector.

(3) Disconnect driver's seat belt pre-tensioner connector 

D-121. 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.

(4) Connect special tool MB991865 to special tool MB991884.
(5) Connect special tool MB991884 to the D-121 harness side 

connector.

(6) Connect the negative battery terminal.
(7) Erase diagnostic trouble code memory, and then check the 

diagnostic trouble code.

Q: Is DTC B1C3B set?

YES : Go to Step 5.
NO :  Replace the driver's seat with belt pre-tensioner. 

(Refer to 

P.52B-457

). Then go to Step 7.

AC507645

A

AC

Lock lever

AC507550AE

Seat belt 
pre-tensioner

Harness side
connector

Locking 
button

Flat-tipped
screwdriver

AC301553 BE

Harness side 
connector

MB991865

(Dummy resistor: 3    )

MB991884 

(Resistor harness)

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-261

STEP 5. Check the driver’s seat belt pre-tensioner circuit. 
Measure the resistance at the SRS-ECU connector C-27.
(1) Disconnect the negative battery terminal.
(2) While pushing the part "A" indicated in the figure of the 

harness side connector, turn the lock lever to the direction 
of the arrow to release the lock lever, and disconnect the 
C-27 SRS-ECU connector.

DANGER

To prevent the seat belt pre-tensioner from deploying 
unintentionally, disconnect the driver’s seat belt 
pre-tensioner connector D-121 to short the squib cir-
cuit.

(3) Disconnect driver's seat belt pre-tensioner connector 

D-121. 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.

(4) Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) 

thick] between terminals 45, 46 and the short spring to 
release the short spring.

(5) Check for continuity between C-27 harness side connector 

terminals 45 and 46.
It should be an open circuit.

Q: Is it open circuit?

YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC B1C3B sets, 
replace the SRS-ECU (Refer to 

P.52B-436

). Then go 

to Step 7.

NO :  Go to Step 6.

AC507645

A

AC

Lock lever

AC507550AE

Seat belt 
pre-tensioner

Harness side
connector

Locking 
button

Flat-tipped
screwdriver

AC507303AN

A

A

C-27 Harness side
connector (front view)

Section
A - A

Cable tie

Short spring

4 mm or more

Terminal

AC608812DG

C-27 Harness side 
connector (front view)

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-262

STEP 6. Check the harness for short circuit between 
SRS-ECU connector C-27 (terminal No.45 and 46) and 
driver’s seat belt pre-tensioner connector D-121 (terminal 
No.1 and 2).
Q: Is the check result normal?

YES : Go to Step 7.
NO :  Repair the harness wires between SRS-ECU 

connector C-27 and driver’s seat belt pre-tensioner 
connector D-121. Then go to Step 7.

STEP 7. 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 B1C3B set?

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

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link 
connector