Mitsubishi Montero (2004+). Manual - part 1201

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-139

DTC 68: Passenger's Seat Belt Pre-Tensioner (Squib) System Fault for Power Supply Circuit 
(Short-Circuited to Power Supply)

SEAT BELT
PRETENSIONER
(RH)

MICROCOMPUTER

AIR BAG DRIVE CIRCUIT

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

NOTE

: CONNECTOR
  COUPLED: ON
  CONNECTOR
  UNCOUPLED: OFF

Passenger's (Front) Seat Belt Pre-tensioner (Squib)

ACX01478AI

CONNECTOR: E-07

E-07 (Y)

AC204603AD

CONNECTOR: E-16

FLOOR 
CONSOLE

E-16

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-140

.

CIRCUIT OPERATION
The side impact sensor includes an analog G sensor 
and CPU, etc. The CPU monitors the analog G sen-
sor output signal. If the CPU judges that the side-air-
bags should be deployed, it sends a fire signal to the 
SRS-ECU to deploy the side-airbags. Besides that, 
the CPU diagnoses the internal components of the 
side impact sensor. If a malfunction occurs, it 
requests the SRS-ECU to set a diagnostic trouble 
code.

.

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 pretensioner (squib) harness

• 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

• MB991911: MUT-III Main Harness B (Vehicles without 

CAN communication system)

• MB991865: Dummy resister

• MB991866: Resister harness

AC204127

AB

CONNECTOR: F-29

F-29 (R)

CENTER 
PILLAR

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-141

STEP 1. 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 the passenger's seat belt pretensioner 

connector F-29.

(3) Connect special tool MB991865 to special tool MB991866.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly as the connector contact pressure may be 
weakened.
(4) Insert special tool MB991866 into the harness side 

connector by backprobing.

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

diagnostic trouble code.

Q: Is DTC 68 set?

YES : Go to Step 2.
NO :  Replace the passenger's seat belt pre-tensioner 

(Refer to 

P.52B-229

). Then go to Step 4. 

AC204127

AD

CONNECTOR: F-29

F-29 (R)

CENTER 
PILLAR

1 2

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC006042 AZ

MB991866
(RESISTOR HARNESS)

F-29 HARNESS 
CONNECTOR

MB991865 (DUMMY 
RESISTOR: 3 

Ω)

F-29 SEAT BELT 
PRE-TENSIONER
CONNECTOR (PASSNGER'S SIDE)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-142

STEP 2. Check the passenger's seat belt pretensioner at 
the SRS-ECU connector E-07.
(1) Disconnect SRS-ECU connector E-07.

(2) Disconnect passenger's seat belt pretensioner connector 

F-29.

(3) Turn the ignition switch to the "ON" position.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly as the connector contact pressure may be 
weakened.
(4) Measure the voltage between E-07 harness connector 

terminals 27, 28 and body ground.
Voltage should measure 0 volt.

Q: Is the circuit normal?

YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC 68 sets, replace 
the SRS-ECU (Refer to 

P.52B-215

). Then go to Step 

4.

NO :  Go to Step 3.

ACX01478AJ

CONNECTOR: E-07

E-07 (Y)

34 35 36 37 38 39 40 41 42

25 26 27 28 29 30 31 32 33

21 22

23 24

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC204127

AD

CONNECTOR: F-29

F-29 (R)

CENTER 
PILLAR

1 2

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC100341

34 35 36 37 38 39 40 41 42

25 26 27 28 29 30 31 32 33

21 22

23 24

AQ

E-07 HARNESS SIDE
CONNECTOR (REAR VIEW)