Mitsubishi Montero (2002-2004). Manual — part 783

52Bb-1

GROUP 52Bb

CONTENTS

SRS AIR BAG DIAGNOSIS . . . . . . . .

52Bb-2

INTRODUCTION TO DIAGNOSIS . . . . . . .

52Bb-2

TROUBLESHOOTING STRATEGY . . . . . .

52Bb-2

SRS DIAGNOSTIC TROUBLE CODE
DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . . . .

52Bb-2

SRS WARNING LIGHT CHECK . . . . . . . . .

52Bb-3

DIAGNOSTIC TROUBLE CODE CHART . .

52Bb-4

TROUBLE SYMPTOM CHART . . . . . . . . . .

52Bb-7

DIAGNOSTIC TROUBLE CODE
PROCEDURES . . . . . . . . . . . . . . . . . . . . . .

52Bb-7

SYMPTOM PROCEDURES . . . . . . . . . . . .

52Bb-158

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DIAGNOSIS

52Bb-2

.

SRS AIR BAG DIAGNOSIS

INTRODUCTION TO DIAGNOSIS

M1524005000288

The SRS system is controlled by the SRS-ECU. The
SRS-ECU judges how severe a collision is by detect-
ing signals from the left and right side impact sen-
sors, front impact sensors, front air bag analog G-
sensor, front air bag safing G-sensor and side-airbag
safing G-sensor. If the impact is over a predeter-
mined level, the SRS-ECU outputs an ignition signal.
At this time, if the safing G-sensor is on, the SRS air
bag will inflate. The SRS warning light in the combi-
nation meter alerts a malfunction of the SRS system.
If the following symptoms occur even when the vehi-
cle has not been in a collision, there may be a mal-
function in the SRS system.

• The SRS warning light does not go off within

approximately seven seconds after the ignition
switch has been turned to the "ON" position.

• The SRS warning light does not illuminate when

the ignition switch is turned to the "ON" position.

Refer to the After-collision Diagnosis (Refer to

P.52Ba-22

.) when inspecting and servicing the vehi-

cle that has been in a collision.

TROUBLESHOOTING STRATEGY

M1524003100289

Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure that you
have exhausted all of the possible ways to find a
SRS fault.
1. Gather information about the problem from the

customer.

2. Verify that the condition described by the

customer exists.

3. Check the vehicle for any SRS diagnostic trouble

codes (SRS DTC).

4. If you cannot verify the condition but there are no

SRS DTCs, the malfunction is intermittent. Refer
to GROUP 00, How to use Troubleshooting

−

Inspection Service Points

− How to Cope With

Intermittent Malfunctions

P.00-13

.

5. If there is a SRS DTC, record the code number,

then erase the code from vehicle memory using
scan tool MB991502.

6. Recreate the SRS DTC set conditions to see if the

same SRS DTC will set again.

• If the same SRS DTC sets again, follow the

Inspection Chart for DTC and find the fault.

• If you cannot get the same SRS DTC to set

again, the malfunction is intermittent. Refer to
GROUP 00, How to use Troubleshooting

−

Inspection Service Points

− How to Cope With

Intermittent Malfunctions

P.00-13

.

SRS DIAGNOSTIC TROUBLE CODE DIAGNOSIS

M1524003200264

Retrieving SRS Diagnostic Trouble Codes

.

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DIAGNOSIS

52Bb-3

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Use scan tool MB991502 to check for SRS diagnostic

trouble codes.

4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991502.

Erasing SRS Diagnostic Trouble Codes

.

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting the scan tool.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Use scan tool MB991502 to erase SRS diagnostic trouble

codes.

4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991502.

SRS WARNING LIGHT CHECK

M1524004300145

1. Check that the SRS warning light illuminates when the

ignition switch is in the "ON" position.

2. Check that it illuminates for approximately seven seconds

and then goes out.

3. If not, check for DTC.

ACX01543

MB991502

AB

16-PIN

ACX01543

MB991502

AB

16-PIN

ACX01667

AT

TEMP

SRS

P
R
N
D

5
4
3
2
1

x1000r/min

2

3

4

5

6

7

8

1

AB

SRS WARNING LIGHT

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DIAGNOSIS

52Bb-4

DIAGNOSTIC TROUBLE CODE CHART

M1524003300379

Inspect according to the inspection chart that is appropriate for the DTC.

DIAGNOSTIC
TROUBLE CODE
NO.

INSPECTION ITEM

REFERENCE PAGE

11

Front impact sensor system circuit short

P.52Bb-7

12

Front impact sensor system either circuit open or no power
supply

P.52Bb-7

13

Front impact sensor system detects either both are open or
no power supply

P.52Bb-7

14

Analog G-sensor system in the SRS-ECU

P.52Bb-13

15

Safing G-sensor short circuit

P.52Bb-13

16

Safing G-sensor open circuit

P.52Bb-13

17

Safing G-sensor for side-airbag faults

P.52Bb-13

21*

2

Driver's air bag module (squib) system fault 1 (Short circuit
between terminals of the squib circuit)

P.52Bb-15

22*

2

Driver's air bag module (squib) system fault 2 (Open in the
squib circuit)

P.52Bb-21

24*

2

Passenger’s (front) air bag module (squib) system fault 1
(Short circuit between terminals of the squib circuit)

P.52Bb-25

25*

2

Passenger’s (front) air bag module (squib) system fault 2
(Open in the squib circuit)

P.52Bb-31

26*

2

Driver's pre-tensioner (squib) system fault 1 (Short circuit
between terminals of the squib circuit)

P.52Bb-34

27*

2

Driver's pre-tensioner (squib) system fault 2 (Open in the
squib circuit)

P.52Bb-39

28*

2

Passenger’s (front) pre-tensioner (squib) system fault 1
(Short circuit between terminals of the squib circuit)

P.52Bb-42

29*

2

Passenger’s (front) pre-tensioner (squib) system fault 2
(Open in the squib circuit)

P.52Bb-47

31

SRS-ECU capacitor circuit voltage too high

P.52Bb-13

32

SRS-ECU capacitor circuit voltage too low

P.52Bb-13

34*

1

Connector lock system detects connector unlocked

P.52Bb-50

35

SRS-ECU air bag condition monitor detects deployed air
bag

P.52Bb-51

41*

1

IG1 power circuit system (fuse No.6 circuit)

P.52Bb-52

42*

1

IG1 power circuit system (fuse No.8 circuit)

P.52Bb-60

43*

1

SRS warning light drive circuit
system fault 1

Light does not illuminate*

1

P.52Bb-66

Light does not switch off

P.52Bb-71

44*

1

SRS warning light drive circuit system fault 2

P.52Bb-75

45

SRS-ECU non-volatile memory (EEPROM) and A/D
converter system

P.52Bb-13