Mitsubishi Montero Sport (2004+). Manual - part 746

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-53

STEP 5. Recheck for diagnostic trouble code.
Q: Is any of DTC 41 or 42 set?

YES : There is no action to be taken.
NO :  This 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.00-7

.) 

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-54

DTC 43: SRS Warning Light Drive Circuit System Fault 1 (Light does not Illuminate.)/SRS Warning 
Light Drive Circuit System Fault 1 (Light does not Switch off.) DTC 44: SRS Warning Light Drive 
Circuit System Fault 2

SRS Warning Light Drive Circuit

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-55

CIRCUIT OPERATION

• Power for the SRS warning light is supplied from 

the ignition switch (IG

1

) circuit.

• The SRS warning light illuminates when the igni-

tion switch is turned "ON," and goes out after 
approximately 7 seconds if there is not a malfunc-
tion in the SRS system.

• The SRS-ECU judges how severe a collision is 

by detecting signals from the left and right 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

• This DTC is set when an open circuit is detected 

for a continuous period of 5 seconds while the 
SRS-ECU is monitoring the SRS warning light 
and the light is OFF. (transistor OFF.) However, if 
the vehicle condition returns to normal, DTC 43 
will be automatically erased, and the SRS warn-
ing light will go out.

• This DTC is set when a short to ground occurs in 

the harness between the SRS warning light and 
SRS-ECU while the SRS-ECU is monitoring the 
light and the light is ON. 

• This DTC is set under one of the following cases 

while the SRS-ECU is monitoring the warning 
light drive circuit:

• When a short circuit occurs in the warning 

light drive circuit.

• When a malfunction is detected in the output 

transistor inside the SRS-ECU.

However, if the vehicle returns to normal condition, 
DTC 44 will be automatically erased, and the SRS 
warning light will go out.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses of connectors

• Blown bulb (for DTC 43)

• Malfunction of the SRS-ECU

• Malfunction of the combination meter (for DTC 

43)

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

AC003826AB

CONNECTORS: C-02, C-04

C-02 (B) C-04

AC003288

CONNECTOR: C-24

AE

SRS-ECU

C-24 (Y)

AC003827AC

CONNECTOR: D-06

JUNCTION BLOCK (FRONT)

D-06

AC003301AB

CONNECTORS: D-08, D-13

D-13

D-08

JUNCTION BLOCK
(REAR)

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-56

STEP 1. Check the SRS warning light line at SRS-ECU 
connector C-24.

(1) Disconnect SRS-ECU connector C-24 and measure at the 

harness side (rear side).

(2) Turn the ignition switch to the "ON position."

(3) Connect terminal 8 to ground.

• The SRS warning light should illuminate.

Q: Does the SRS warning light illuminate?

YES : Replace the SRS-ECU. Refer to 

P.52B-82

. Then go 

to Step 6.

NO :  Go to Step 2.

STEP 2. Check the SRS warning light bulb.
Q: Has the SRS warning light bulb blown?

YES : Replace the SRS warning light bulb. Then go to Step 

6.

NO :  Go to Step 3.

AC202743

20

19

18

17

7

15

8

16

6

5

4

12

13 14

3

2

1

9 10 11

CONNECTOR: C-24

C-24 (Y)

C-24 HARNESS CONNECTOR:
HARNESS SIDE 
(REAR VIEW) 

AD

SRS-ECU

AC003302

<MEASURING METHOD: SAMPLE>

MB991222

AC

C-24 HARNESS CONNECTOR:
HARNESS SIDE