Mitsubishi Montero (2004+). Manual — part 1174

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-31

NOTE: After inspecting intermediate connector D-28, inspect
the wiring harness. If intermediate connector D-28 is damaged,
repair or replace it. Refer to GROUP 00E, Harness Connector
Inspection

P.00E-2

. Then go to Step 4.

• Check the front impact sensor output line for open or

short circuit.

Q: Is the check result satisfactory?

YES : Go to Step 4.
NO : Repair the wiring harness.

Step 4. Recheck for diagnostic trouble code.
Q: Is DTC 1A, 1B, 1C, 1D, 2A, 2B, 2C or 2D set?

YES : Replace the SRS-ECU (Refer to

P.52B-215

).

NO : The procedure is complete. (If no malfunctions are

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

).

AC204231 AB

D-28

CONNECTOR : D-28

D-28

38

1213

11

26

14

1

20

6

232425

37

31

36

30

10

9

2122

35

8

7

34

17

29

1819

5

4

1516

33

28

32

27

3

2

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-32

DTC 11: Front impact sensor system circuit short
DTC 12: Front impact sensor system either circuit open or on power supply
DTC 13: Front impact sensor system detects either both are open or no power supply

.

AC102902AB

Front Impact Sensor Circuit

AC204229

CONNECTOR: A-23

AB

A-23 (Y)

AC204228

CONNECTOR: A-30

AB

A-30 (Y)

AC204230

CONNECTOR : D-28

AB

D-28

ACX01478 AG

CONNECTOR: E-08

E-08 (Y)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-33

CIRCUIT OPERATION

• When the left and right front impact sensors

detect a collision, the switches inside the sensors
turns ON.

• SRS-ECU judges how severe a collision is by

detecting signals from the front impact sensors
and the analog G-sensor. If the impact is over a
predetermined level, the SRS-ECU outputs an
ignition signal. At this time, if the safing G-sensor
is on, the SRS air bag will inflate.

.

DTC SET CONDITIONS
These DTC are set if there is abnormal resistance
between the input terminals of the front impact sen-
sors.
The most likely causes for these codes to be set are
shown in the table below:

.

TROUBLESHOOTING HINTS

• Malfunction of the front impact sensor

• Damaged wiring harnesses or connectors

• Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:

• MB991222: Probe

• 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)

DTC

SYMPTOMS

11

• Short circuit in front impact sensor or harness

• Short circuit in front impact sensor harness leading to the vehicle body ground

• Short circuit in front impact sensor harness leading to the power supply

12

• Open circuit in either left or right from impact sensor or harness

• Short circuit in front impact sensor harness leading to the power supply

13

• Open circuit in both left and right front impact sensor or harness

• Short circuit in front impact sensor harness leading to the power supply

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-34

STEP 1. Check the front impact sensor.
(1) Measure the resistance between terminals and check

whether it is within the standard value.

Standard value: 820

± 82 Ω

(2) Check for continuity between the terminal and bracket.

There should be no continuity.

Q: Does the resistance meet the value above, and is there

continuity?
YES : Go to Step 2.
NO : Replace front impact sensor (Refer to

P.52B-211

).

AC204205AB

ACX00598AB