Mitsubishi L200. Manual — part 591

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-35

PROBABLE CAUSE
Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

Replace the SRS-ECU (Refer to

P.52B-266

).

B1467

Safing G-sensor (front air bag)

• Open circuit in the safing G-sensor

B1468

• Short circuit in the safing G-sensor

B1478

Capacitor

• Voltage at the capacitor terminal is higher than the

specified value for five seconds or more

B1479

• Voltage at the capacitor terminal is lower than the

specified value for five seconds or more (This is not
detected if diagnosis code B1476 or B1477 indicating
battery positive voltage drop has been set).

B1496

Non-volatile memory (EEPROM)

• When the non-volatile memory (EEPROM) is

abnormal

B1497

Application specific integrated
circuit (for frontal activation)

• When the application specific integrated circuit (frontal

activation) is abnormal

B1498

ROM or RAM

• When the ROM or RAM is abnormal

B1499

Collision decision

• If this code is set before the air bags have deployed,

an internal failure may have occurred in the SRS-
ECU.

B1550

SRS warning lamp drive circuit

• Failure in SRS warning lamp drive circuit

B1557

Application specific integrated
circuit

• When the application specific integrated circuit is

abnormal

B1607

Seat belt pre-tensioner (driver's
side) (squib ignition drive circuit)

• Short circuit in the squib ignition drive circuit

B1608

• Open circuit in the squib ignition drive circuit

B1613

Seat belt pre-tensioner
(passenger’s side) (squib ignition
drive circuit)

• Short circuit in the squib ignition drive circuit

B1614

• Open circuit in the squib ignition drive circuit

Code No.

Part/Circuit integral to SRS-
ECU

Trouble causes

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-36

Code No.B1410: Passenger's (front) air bag module (squib) system (short-circuited between
terminals of the squib circuit)

IND

AC805767

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

PASSENGER'S AIR BAG
CUT OFF SWITCH

SRS-ECU

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

AC

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 one passenger’s (front)
air bag squib wire shorted to the other.

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-37

PROBABLE CAUSES

• Improper engaged connector or defective short

spring*

• Short circuit between the passenger's (front) air

bag module (squib) circuit terminals

• Damaged connector(s)

• Malfunction of the passenger’s air bag cut off

switch

• Malfunction of the SRS-ECU

NOTE: *: The squib circuit connectors integrate a
"short" spring (which prevents the air bag from
deploying unintentionally due to static electricity by
shorting the positive wire to the earth wire in the
squib circuit when the connectors are discon-
nected).Therefore, if connector C-02 or C-131 is
damaged or improperly engaged, the short spring
may not be released when the connector is con-
nected.

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code.

Q: Is diagnosis code B1519 set?

YES :

Go to Step 2.

NO :

Go to Step 3.

STEP 2. Connector lock check: SRS-ECU
connector C-131. (M.U.T.-III diagnosis code)
(1) Disconnect the negative battery terminal.

AC501670

AB

C-131 (Y)

Connector: C-131

Harness side
connector
(rear view)

(2) Disconnect the connectors C-131 and then

reconnect them.

(3) Connect the negative battery terminal.
(4) Erase the diagnosis code memory, and check the

diagnosis code.

Q: Is diagnosis code B1410 set?

YES :

Go to Step 3.

NO :

The procedure is complete. It is assumed
that diagnosis code B1410 set as connector
C-131 was engaged improperly.

STEP 3. Connector lock check: SRS-ECU
connector C-131 and passenger’s (front) air bag
module connector C-02. (M.U.T.-III diagnosis
code)
(1) Disconnect the negative battery terminal.

AC501670

AB

C-131 (Y)

Connector: C-131

Harness side
connector
(rear view)

AC509788

C-02 (R)

AC

Glove box striker

2 1

Harness side
connector
(front view)

Lock
lever

Connector: C-02

(2) Disconnect connectors C-02 and C-131, and then

reconnect them. For connector C-02, pull up the
harness side lock lever with a nail and disconnect
the connector lock.

(3) Connect the negative battery terminal.
(4) Erase the diagnosis code memory, and check the

diagnosis code.

Q: Is diagnosis code B1410 set?

YES :

Go to Step 4.

NO :

The procedure is complete. It is assumed
that diagnosis code B1410 set as connector
C-02 or C-131 was engaged improperly.

STEP 4. 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 5.

NO :

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

P.52B-287

).

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-38

STEP 5. 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 B1410 set?

YES :

Go to Step 6.

NO :

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

P.52B-268

).

STEP 6. Resistance measurement at SRS-ECU
connector C-131.
(1) Disconnect the negative battery terminal.

AC501670

AB

C-131 (Y)

Connector: C-131

Harness side
connector
(rear view)

(2) Disconnect SRS-ECU connector C-131.

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
lock.

AC006036

Section
A - A

C-131Harness side connectors
(front view)

Cable tie

Short spring

4 mm or more

Terminal

BC

A

A

CAUTION

Insert an insulator such as a cable tie to a depth
of 4 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 9, 10 and the short spring to
release the short spring.

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