Mitsubishi 380. Manual - part 804

SRS AIR BAG DIAGNOSIS

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-140

STEP 1. Using diagnostic tool MB991958, diagnose the 
CAN bus line.

CAUTION

To prevent damage to diagnostic tool MB991958, always 
turn the ignition switch to the "LOCK" (OFF) position 
before connecting or disconnecting diagnostic tool 
MB991958.
(1) Connect diagnostic tool MB991958. Refer to "How to 

connect the diagnostic tool 

P.52B-19

."

(2) Turn the ignition switch to "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the check result satisfactory?

YES : Go to Step 2
NO :  Repair the CAN bus lines (Refer to GROUP 54C, 

Diagnosis-Can Bus Diagnostic Chart ). .

STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 3.
NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Use Troubleshooting/Inspection 
Service Points 

− How to Cope with Intermittent 

Malfunctions ).

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-141

STEP 3. Check the side-airbag module (LH). (Using 
diagnostic tool MB991958, read the diagnostic trouble 
code.)
(1) Disconnect the negative battery terminal.
(2) Disconnect the side-airbag module (LH) connector D-24.

(3) Connect special tool MB991865 to special tool MB991866.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly, as the connector contact pressure may be 
weakened.
(4) Insert special tool MB991866 into the D-24 harness side 

connector by testprobe.

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

diagnostic trouble code.

Q:  Is DTC B1433 set?

YES : Go to Step 4.
NO :  Replace the seatback frame of the front seat (LH) 

(Refer to GROUP 52A, Front Seat 

P.52A-33

). Then 

go to Step 6.

AC307778

CONNECTOR : D-24

AC

D-24 (R)

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

AC006042BP

MB991866
(RESISTOR HARNESS)

D-24 HARNESS SIDE
CONNECTOR

D-24 SIDE-AIRBAG 

MODULE (LH) CONNECTOR

MB991865 (DUMMY 
RESISTOR: 3

 

Ω)

SRS AIR BAG DIAGNOSIS

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-142

STEP 4. Check the side-airbag module (LH) circuit. 
Measure the resistance at the SRS-ECU connector D-27.
(1) Disconnect SRS-ECU connector D-27.

(2) Disconnect side-airbag module (LH) connector D-24.

CAUTION

Do not insert a test probe into the terminal from its front 
side directly, as the connector contact pressure may be 
weakened.
(3) Check for continuity between D-27 harness side connector 

terminals 9, 10 and body ground.
It should be open circuit.

Q: Does continuity exist? 

YES : Go to Step 5.
NO :  Erase the diagnostic trouble code from memory, and 

check the diagnostic trouble code. If DTC B1433 sets, 
replace the SRS-ECU (Refer to 

P.52B-234

). Then go 

to Step 6.

24DB064A

CONNECTOR: D-27

SRS-ECU

D-27 (Y)

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

D-27 Floor 

harness

connector

(rear view)

AC307778

CONNECTOR : D-24

AC

D-24 (R)

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

24DB078A

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

D-27 FLOOR HARNESS

SIDE CONNECTOR

(REAR VIEW)

SRS AIR BAG DIAGNOSIS

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-143

STEP 5. Check the harness wires for short circuit to 
ground between SRS-ECU connector D-27 (terminal No.9 
and 10) and side-airbag module (LH) connector D-24 
(terminal No.1 and 2).
Q: Are the harness wires between SRS-ECU connector 

D-27 (terminal No.9 and 10) and side-airbag module (LH) 
connector D-24 (terminal No.1 and 2) in good condition? 
YES : Go to Step 6.
NO :  Replace the harness wires between SRS-ECU 

connector D-27 and side-airbag module (LH) 
connector D-24. Then go to Step 6. 

STEP 6. Recheck for diagnostic trouble code. 
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1433 set?

YES : Return to Step 1.
NO :  The procedure is complete.

AC307778

CONNECTOR : D-24

AC

D-24 (R)

2

1

HARNESS SIDE
CONNECTOR
(REAR VIEW)

24DB064A

CONNECTOR: D-27

SRS-ECU

D-27 (Y)

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

D-27 Floor 

harness

connector

(rear view)

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827