Mitsubishi Outlander GS45X. Manual - part 1446

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-279

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-27 or D-130 is damaged or improperly 
engaged, the short spring may not be released when 
the connector is connected.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A (Vehicles with 

CAN Communication System)

• MB991865: Dummy resistor

• MB991884: Resister harness

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-28

."

(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-17

).

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link 
connector

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-280

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 passenger’s 
seat belt pre-tensioner connector D-130. (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-130 harness side connectors, 

connect the connectors again. For the D-130 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 B1C4A set?

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

B1C4A set because connector C-27 or D-130 was 
engaged improperly.

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link 
connector

AC507645

A

AC

Lock lever

AC506363AB

Seat belt 
pre-tensioner

Floor wiring harness side
connector (2-pin, black)

Locking 
button

Flat-tipped
screwdriver

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-281

STEP 4. Check the passenger'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 passenger's seat belt pre-tensioner connector 

D-130. 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-130 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 B1C4A set?

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

(Refer to 

P.52B-457

). Then go to Step 7. 

AC507645

A

AC

Lock lever

AC506363AB

Seat belt 
pre-tensioner

Floor wiring harness side
connector (2-pin, black)

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-282

STEP 5. Check the passenger'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 passenger’s seat belt 
pre-tensioner connector D-130 to short the squib cir-
cuit.

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

D-130. 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 43, 44 and the short spring to 
release the short spring.

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

terminals 43 and 44.
It should be an open circuit.

Q: Is it open circuit?

YES : Erase the diagnostic trouble code memory, and check 

diagnostic trouble code. If DTC B1C4A set, replace 
the SRS-ECU (Refer to 

P.52B-436

). Then go to Step 

7.

NO :  Go to Step 6.

AC507645

A

AC

Lock lever

AC506363AB

Seat belt 
pre-tensioner

Floor wiring harness side
connector (2-pin, black)

Locking 
button

Flat-tipped
screwdriver

AC507303AL

A

A

C-27 Harness side
connector (front view)

Section
A - A

Cable tie

Short spring

4 mm or more

Terminal

AC608812DK

C-27 Harness side 
connector (front view)