Mitsubishi Montero (2004+). Manual - part 1213

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-187

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
These DTC are set if communication between the 
side impact sensor (RH) and the SRS-ECU is not 
possible or faulty.

.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors

• Malfunction of the side impact sensor (RH)

• Malfunction of the SRS-ECU

.

DIAGNOSIS

Required Special Tool:

• 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)

STEP 1. Check the side impact sensor (RH). (Using scan 
tool MB991958, read the diagnostic trouble code).
(1) Disconnect the negative battery terminal.
(2) Replace the side impact sensor (RH) with the side impact 

sensor (LH)

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

diagnostic trouble code.

Q: Is DTC 79 or 93 out put?

YES : Replace the side impact sensor (RH) with a new one 

(Refer to 

P.52B-227

). Go to Step 3.

NO :  Go to Step 2.

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-188

STEP 2. Check the harness wires for open circuit or short 
circuit between SRS-ECU connector E-07 (terminal No.40 
and 42) and side impact sensor (RH) connector F-19 
(terminal No.1 and 2).

NOTE: After inspecting intermediate connector E-16 inspect 
the wiring harness. If the intermediate connector E-16 is dam-
aged, repair or replace it. Refer to GROUP 00E, Harness Con-
nector Inspection 

P.00E-2

. Then go to Step 3.

Q: Are the harness wires between SRS-ECU connector 

E-07 (terminal No.40 and 42) and side impact sensor 
(RH) connector F-19 (terminal No.1 and 2) is good 
condition? 
YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC 89 or 96 sets, 
replace the SRS-ECU (Refer to 

P.52B-215

). Then go 

to Step 3.

NO :  Repair the harness wires between SRS-ECU 

connector E-07 and side impact sensor (RH) 
connector F-19. Then go to Step 3.

STEP 3. Recheck the diagnostic trouble code.
Q: Is DTC 89 or 96 set?

YES : Refer 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)

AC204129

AD

CONNECTOR: F-19

SIDE IMPACT 
SENSOR

F-19 (Y)

CENTER 
PILLER

HARNESS SIDE 
CONNECTOR 
(FRONT VIEW)

2

1

AC204603AE

CONNECTOR: E-16

FLOOR 
CONSOLE

E-16

5

4

3

2

1

E-16

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-189

DTC 91: Left Hand Side-Impact Sensor Power Supply Circuit System

.

AC204437AB

Side Impact Sensor (LH) Power Supply Circuit

ACX01478AI

CONNECTOR: E-07

E-07 (Y)

AC204603AB

CONNECTOR: E-19

FLOOR 
CONSOLE

E-19

AC204128

AB

CONNECTOR: F-13

FRONT SEAT

SIDE IMPACT 
SENSOR

F-13 (Y)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-190

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 will set when the power supply voltage to 
the left-side impact sensor remains less than a pre-
determined value for five seconds. However, if the 
system returns to normal condition, code number 91 
will be erased automatically and the SRS warning 
light will go out.

.

TROUBLESHOOTING HINTS

• Damaged wiring harness or connectors

• Malfunction of the side-airbag module (LH) 

(squib)

• 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)

• MB991223 (MB991222): Harness set (Probe)

STEP 1. Check the side impact sensor (LH) power supply 
circuit at the side impact sensor (LH) connector F-13.
(1) Disconnect the negative battery terminal.
(2) Disconnect left hand side impact sensor connector F-13, 

and measure at the wiring harness.

(3) Connect the negative battery terminal.
(4) 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.
(5) Measure the voltage between F-13 harness connector 

terminal 2 and the ground.
Voltage should measure 9 volts or more.

Q: Is the measured voltage within the specified range?

YES : Replace the side impact sensor (LH) (Refer to 

P.52B-227

). Then go to Step 3.

NO :  Go to Step 2.

AC204128

CONNECTOR: F-13

AD

F-13 (Y)

HARNESS SIDE 
CONNECTOR
(FRONT VIEW)

FRONT SEAT

SIDE IMPACT 
SENSOR

2

1

AC309376

F-13 HARNESS SIDE
CONNECTOR 
(FRONT VIEW)

AB