Mitsubishi Montero (2004+). Manual - part 1200

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-135

.

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 outputs 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 driver's seat belt 
pre-tensioner (squib).

.

TROUBLESHOOTING HITS

• Damaged wiring harnesses or connectors

• Short to the ground in the driver's seat belt pre-

tensioner (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

AC204126

AB

CONNECTOR: F-27

F-27 (R)

CENTER 
PILLAR

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-136

STEP 1. Check the driver's seat belt pre-tensioner. (Using 
scan tool MB991958, read the diagnostic trouble code).
(1) Disconnect the negative battery terminal.
(2) Disconnect the driver's seat belt pretensioner connector 

F-27.

(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 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 67 set?

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

P.52B-229

). Then go to Step 4. 

AC204126

AD

CONNECTOR: F-27

F-27 (R)

CENTER 
PILLAR

1 2

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC006042 AY

MB991866
(RESISTOR HARNESS)

F-27 HARNESS 
CONNECTOR

MB991865 (DUMMY 
RESISTOR: 3 

Ω)

F-27 SEAT BELT 
PRE-TENSIONER
CONNECTOR (DRIVER'S SIDE)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-137

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

(2) Disconnect driver's seat belt pretensioner connector F-27.

CAUTION

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

terminals 29, 30 and body ground.
It should be open circuit.

Q: Does continuity exist?

YES : Go to Step 3.
NO :  Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC 67 sets, replace 
the SRS-ECU (Refer to 

P.52B-215

). Then go to Step 

4.

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)

AC204126

AD

CONNECTOR: F-27

F-27 (R)

CENTER 
PILLAR

1 2

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC201666

34 35 36 37 38 39 40 41 42

25 26 27 28 29 30 31 32 33

2122

23 24

E-07 HARNESS SIDE
CONNECTOR (REAR VIEW)

AL

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-138

STEP 3. Check harness wires for short circuit to ground 
between SRS-ECU connector E-07 (terminal No.29 and 30) 
and driver's seat belt pre-tensioner connector F-27 
(terminal No.1 and 2).

NOTE: After inspecting intermediate connector E-19, inspect 
the wiring harness. If the intermediate connector E-19 is dam-
aged, repair or replace it (Refer to GROUP 00E, Harness Con-
nector Inspection). Then go to Step 4.
Q: Are the harness wires between SRS-ECU connector 

E-07 (terminal No.29 and 30) and driver's seat belt 
pre-tensioner connector F-27 (terminal No.1 and 2) in 
good condition?
YES : Go to Step 4.
NO :  Repair the harness wires between SRS-ECU 

connector E-07 and driver's seat belt pre-tensioner 
connector F-27. Then go to Step 4.

STEP 4. Recheck for diagnostic trouble code. 
Q: Is DTC 67 set?

YES : Return to Step 1.
NO :  The procedure is complete. (If no malfunctions are not 

found in all steps, an intermittent malfunction is 
suspected. Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunction 

P.00-6

). 

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)

AC204126

AD

CONNECTOR: F-27

F-27 (R)

CENTER 
PILLAR

1 2

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC204603AC

CONNECTOR: E-19

FLOOR 
CONSOLE

E-19

2

1

4

3

E-19