Mitsubishi Montero Sport (2004+). Manual - part 738

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-21

SRS AIR BAG DIAGNOSIS

INTRODUCTION TO SRS DIAGNOSIS

M1524005000385

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 front impact sen-
sors and the analog G-sensor. If the impact is over a 
predetermined level, the SRS-ECU outputs an igni-
tion signal. At this time, if the safing G-sensor is on, 
the SRS air bag will inflate.
The SRS warning light in the combination meter 
alerts a malfunction of the SRS system.

If the following symptoms occur even when the vehi-
cle has not collided, there may be a malfunction.

• The SRS warning light does not go off within 

approximately 7 seconds after the ignition switch 
has been turned "ON."

• The SRS warning light does not illuminate when 

the ignition switch is turned "ON."

Refer to the Post-collision Diagnosis when inspecting 
and servicing the vehicle that has been in a collision 
(Refer to 

P.52B-74

).

TROUBLESHOOTING STRATEGY

M1524003100472

Use these steps to plan your diagnostic strategy. If 
you follow them carefully, you will be sure that you 
have exhausted most 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 cus-

tomer exists.

3. Check the vehicle for any Diagnostic Trouble 

Code (DTC).

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

DTC's, the malfunction is intermittent. Refer to 
GROUP 00, How to use Troubleshooting/Inspec-
tion Service Point 

− How to Cope With Intermit-

tent Malfunctions 

P.00-7

.

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

then erase the code from vehicle memory using 
scan tool MB991958.

6. Recreate the DTC set conditions to see if the 

same DTC will set again.

• If the same DTC sets again, follow the DTC 

Chart and find the fault.

• If you cannot get the same DTC to set again, 

the malfunction is intermittent. Refer to 
GROUP 00, How to use Troubleshoot-
ing/Inspection Service Point 

− How to Cope 

With Intermittent Malfunctions 

P.00-7

.

DIAGNOSTIC FUNCTION

M1524013800126

HOW TO CONNECT THE SCAN TOOL (MUT-III)

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

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-22

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
1. Ensure that the ignition switch is at the "LOCK" (OFF) 

position.

2. Start up the personal computer.
3. Connect special tool MB991827 to special tool MB991824 

and the personal computer.

4. Connect special tool MB991911 to special tool MB991824.
5. Connect special tool MB991911 to the data link connector.
6. Turn the power switch of special tool MB991824 to the "ON" 

position.
NOTE: When special tool MB991824 is energized, special 
tool MB991824 indicator light will be illuminated in a green 
color.

7. Start the MUT-III system on the personal computer.
NOTE: Disconnecting scan tool MB991958 is the reverse of the 
connecting sequence, making sure that the ignition switch is at 
the "LOCK" (OFF) position.

HOW TO READ AND ERASE DIAGNOSTIC 
TROUBLE CODES

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

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
NOTE: If the battery voltage is low, diagnostic trouble codes will 
not be set. Check the battery if scan tool MB991958 does not 
display.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "Interactive Diagnosis" from the start-up screen.
4. Select "System select."
5. Choose "SRS-AIR BAG" from the "BODY" tab.
6. Select "MITSUBISHI."
7. Select "Diagnostic Trouble Code."
8. If a DTC is set, it is shown.
9. Choose "Erase DTCs" to erase the DTC.

AK303629AB

MB991911

MB991827

MB991824 

16-PIN

AC206894

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-23

M1524003300595

INSPECTION CHART FOR DTC'S

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

DTC

ON-BOARD DIAGNOSTIC ITEM

REFERENCE 
PAGE

1A

Front impact sensor (LH) circuit short

P.52B-25

1B

Front impact sensor (LH) circuit open

P.52B-25

1C

Front impact sensor (LH) short-circuited to power supply

P.52B-25

1D

Front impact sensor (LH) short-circuited to ground

P.52B-25

2A

Front impact sensor (RH) circuit short

P.52B-25

2B

Front impact sensor (RH) circuit open

P.52B-25

2C

Front impact sensor (RH) short-circuited to power supply

P.52B-25

2D

Front impact sensor (RH) short-circuited to ground

P.52B-25

14

Analog G-sensor system in the SRS-ECU

P.52B-31

15 

Safing G-sensor short circuit

P.52B-31

16

Safing G-sensor open circuit

P.52B-31

21*

2

Driver's side air bag module (squib) system fault 1

P.52B-32

22*

2

Driver's side air bag module (squib) system fault 2

P.52B-32

24*

2

Passenger (front) side air bag module (squib) system fault 1

P.52B-36

25*

2

Passenger (front) side air bag module (squib) system fault 2

P.52B-36

26*

2

Driver's side seat belt pre-tensioner (squib) system fault 1

P.52B-40

27*

2

Driver's side seat belt pre-tensioner (squib) system fault 2

P.52B-40

31

SRS-ECU capacitor circuit voltage too high

P.52B-31

32

SRS-ECU capacitor circuit voltage too low

P.52B-31

34*

1

Connector lock system detects connector unlocked

P.52B-44

35

SRS-ECU air bag condition monitor detects deployed air bag

P.52B-46

39

Airbags deployed simultaneously

P.52B-46

41*

1

IG

1

 power circuit system (fuse No.7 circuit)

P.52B-47

42*

1

IG

1

 power circuit system (fuse No.8 circuit)

P.52B-47

43*

1

SRS warning light driver circuit system 
fault 1

Light does not illuminate

P.52B-54

Light does not switch off

P.52B-54

44*

1

SRS warning light driver circuit system fault 2

P.52B-54

45

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

P.52B-31

46*

1

Improperly installed SRS-ECU

P.52B-61

51

Driver's side air bag module (squib ignition driver circuit) system detected short 
circuit

P.52B-31

52

Driver's side air bag module (squib ignition driver circuit) system detected open 
circuit

P.52B-31

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-24

NOTE: 

.

1. *1: If the vehicle condition returns to normal, the DTC will be automatically erased, and the SRS warning 

light will return to normal.

2. *2: However, if no DTC resets, the SRS warning light will be switched off (The DTC will be retained).
3. If the vehicle has a discharged battery, it will store the DTC's 41 or 42. When these DTC's are read, check 

the battery condition.

54

Passenger (front) side air bag module (squib ignition drive circuit) system 
detected short circuit

P.52B-31

55

Passenger (front) side air bag module (squib ignition drive circuit) system 
detected open circuit

P.52B-31

56

Driver's side seat belt pre-tensioner (squib ignition driver circuit) system 
detected short circuit

P.52B-31

57

Driver's side seat belt pre-tensioner (squib ignition driver circuit) system 
detected open circuit

P.52B-31

61

Driver's side air bag module (squib) system fault for power supply circuit

P.52B-32

62

Driver's side air bag module (squib) system fault for ground circuit

P.52B-32

64

Passenger (front) side air bag module (squib) system fault for power supply 
circuit

P.52B-36

65

Passenger (front) side air bag module (squib) system fault for ground circuit

P.52B-36

66

Driver side seat belt pre-tensioner (squib) system fault for power supply circuit

P.52B-40

67

Driver side seat belt pre-tensioner (squib) system fault for ground circuit

P.52B-40

DTC

ON-BOARD DIAGNOSTIC ITEM

REFERENCE 
PAGE