Mitsubishi L200. Manual - part 611

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-115

lock.

AC801565

Section
A - A

C-154 Harness side connectors
(front view)

Cable tie

Terminal

 7 mm or more

AE

Short spring

A

A

CAUTION

Insert an insulator such as a cable tie to a depth 
of 7 mm or more, otherwise the short spring will 
not be released.
(4) Insert a cable tie [3 mm wide, 0.5 mm thick] 

between terminals 21, 22 and the short spring to 
release the short spring.

(5) Check that the passenger's air bag cut off switch 

is "ON" position.

AC800962 BJ

C-154 
Harness side 
connector 
(rear view)

C-02 
Harness side 
connector 
(rear view)

CAUTION

Do not insert a test probe into the terminal from 
its front side directly as the connector contact 
pressure may be weakened.
(6) Resistance measurement between the following 

terminals. 

• SRS-ECU connector C-154 terminal No.21 

and the passenger’s (front) air bag module 
connector C-02 terminal No.1

• SRS-ECU connector C-154 terminal No.22 

and the passenger’s (front) air bag module 
connector C-02 terminal No.2

OK: Continuity (Less than 2 

Ω)

Q: Are the check results normal?

YES : 

Go to Step 4 .

NO : 

Repair the harness wires between SRS-
ECU connector C-154 (terminal No.21 and 
22) and passenger’s (front) air bag module 
connector C-02 (terminal No.1 and 2).

STEP 4. Check whether the diagnosis code is 
reset.

Q: Is diagnosis code B1411 set?

YES : 

Replace the SRS-ECU (Refer to 

P.52B-

266

).

NO : 

An intermittent malfunction is suspected 
(Refer to GROUP 00, How to Cope with 
Intermittent Malfunction ).

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-116

Code No.B1412: Passenger's (front) air bag module (squib) system (short-circuited to the earth)

IND

AC805798

PASSENGER'S (FRONT) 
AIR BAG MODULE 
(SQUIB) 

Wire colour code
B : Black     LG : Light green     G : Green     L : Blue     W : White     Y : Yellow     SB : Sky blue
BR : Brown     O : Orange     GR : Grey     R : Red     P : Pink     V : Violet     PU : Purple

J/B
(FUSE      )

PASSENGER'S 
AIR BAG 
CUT OFF 
INDICATOR

CONNECTOR LOCK SWITCH 

CONNECTOR COUPLED: ON 

CONNECTOR UNCOUPLED: OFF

NOTE

:   

 

 

Passenger's (Front) Air Bag Module (Squib) Circuit

PASSENGER'S AIR BAG 
CUT OFF SWITCH

AC

SRS-ECU

OPERATION

• The SRS-ECU judges how severe a collision is 

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

• The ignition signal is input to the air bag module 

to inflate the air bag.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if the passenger's (front) 
air bag squib wire(s) are short-circuited to the earth.

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-117

PROBABLE CAUSES

• Damaged harness wires and connectors

• Short to the earth in the passenger's (front) air 

bag module (squib) harness

• Malfunction of the passenger’s air bag cut off 

switch

• Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the passenger’s air bag cut off 
switch.
Check the passenger's air bag cut off switch (Refer 
to 

P.52B-288

).

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Replace passenger’s air bag cut off switch 
(Refer to 

P.52B-287

).

STEP 2. Check the diagnosis code by connecting 
a dummy resistor. (M.U.T.-III diagnosis code)
(1) Disconnect the negative battery terminal.

AC509788

C-02 (R)

AC

Glove box striker

2 1

Harness side 
connector 
(front view)

Lock 
lever

Connector: C-02

(2) Disconnect passenger’s (front) air bag module 

connector C-02. Pull up the harness side lock 
lever with a nail and disconnect the connector 
lock.

AC300956 AP

MB991865
(Dummy resistor: 3    )

MB991866 

(Resistor harness)

C-02 Passenger's 

(front) air bag 

module connector

C-02 Harness side 

connector

(3) Connect special tool dummy resistor (MB991865) 

to special tool resistor harness (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 harness 

side connector C-02 by backprobing.

(5) Check that the passenger's air bag cut off switch 

is "ON" position.

(6) Connect the negative battery terminal.
(7) Erase the diagnosis code memory, and check the 

diagnosis code.

Q:  Is diagnosis code B1412 set?

YES : 

Go to Step 3.

NO : 

Replace the passenger's (front) air bag 
module (Refer to 

P.52B-268

). 

STEP 3. Resistance measurement at the SRS-
ECU connector C-154.
(1) Disconnect the negative battery terminal.

AC801404

AJ

Connector: C-154

C-154 (Y)

Harness side 
connector 
(rear view)

(2) Disconnect SRS-ECU connector C-154.

AC509788

C-02 (R)

AC

Glove box striker

2 1

Harness side 
connector 
(front view)

Lock 
lever

Connector: C-02

DANGER

To prevents the air bag from deploying unin-
tentionally, disconnect the passenger’s 
(front) air bag module connector C-02 to 
short the squib circuit.

(3) Disconnect passenger’s (front) air bag module 

connector C-02. Pull up the harness side lock 
lever with a nail and disconnect the connector 

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-118

lock.

AC801565

Section
A - A

C-154 Harness side connectors
(front view)

Cable tie

Terminal

 7 mm or more

AE

Short spring

A

A

CAUTION

Insert an insulator such as a cable tie to a depth 
of 7 mm or more, otherwise the short spring will 
not be released.
(4) Insert a cable tie [3 mm wide, 0.5 mm thick] 

between terminals 21, 22 and the short spring to 
release the short spring.

(5) Check that the passenger's air bag cut off switch 

is "ON" position.

AC800962BK

C-154 Harness side connector 
(rear view)

CAUTION

Do not insert a test probe into the terminal from 
its front side directly as the connector contact 
pressure may be weakened.
(6) Resistance measurement between C-154 

harness side connector terminals 21, 22 and 
body earth.

OK: Open circuit

Q: Is the check result normal? 

YES : 

Go to Step 4.

NO : 

Repair the harness wires between SRS-
ECU connector C-154 (terminal No.21 and 
22) and passenger's (front) air bag module 
connector C-02 (terminal No.1 and 2).

STEP 4. Check whether the diagnosis code is 
reset.

Q: Is diagnosis code B1412 set?

YES : 

Replace the SRS-ECU (Refer to 

P.52B-

266

). 

NO : 

An intermittent malfunction is suspected 
(Refer to GROUP 00, How to Cope with 
Intermittent Malfunction ).