Mitsubishi Colt Ralliart. Manual — part 565

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-98

DIAGNOSIS PROCEDURE

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

(2) Disconnect driver's seat belt pre-tensioner

connector C-28. Use a flat-tipped screwdriver to
pull out the locking button at the harness side
connector, and then disconnect the connector.

(3) Connect special tool dummy resistor (MB991865)

to special tool resistor harness (MB991884).

(4) Connect special tool (MB991884) to the C-28

harness side connector.

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

diagnosis code.

Q: Is diagnosis code 67 set?

YES : .

Go to Step 2.

NO : .

Replace the driver's seat belt with

pre-tensioner (Refer to

P.52B-159

).

STEP 2. Resistance measurement at the
SRS-ECU connector B-35.
(1) Disconnect the negative battery terminal.

(2) Disconnect SRS-ECU connector B-35.

DANGER

To prevents the air bag from deploying unin-
tentionally, disconnect the driver’s seat belt
pre-tensioner connector C-28 to short the
squib circuit.

(3) Disconnect driver's seat belt pre-tensioner

connector C-28. Use a flat-tipped screwdriver to
pull out the locking button at the harness side
connector, and then disconnect the connector.

AC207222 AF

Harness side
connector
(front view)

Connector: C-28

C-28 (B)

Centre

pillar

AC208430AE

Pre-tensioner

connector

Locking

button

Harness side

connector

Flat-tipped

screwdriver

MB991865
(Dummy resistor : 3

Ω)

C-28 Harness side
connectors

MB991884
(Resistor
harness)

AF

AC206285

AF

B-35 (Y)

Connector: B-35

Harness side
connector
(rear view)

AC207222 AF

Harness side
connector
(front view)

Connector: C-28

C-28 (B)

Centre

pillar

AC208430AE

Pre-tensioner

connector

Locking

button

Harness side

connector

Flat-tipped

screwdriver

Main

Index

Group

TOC

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-99

CAUTION

Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.
(4) Resistance measurement between B-35 harness

side connector terminals 7, 8 and body earth.

OK: Open circuit

Q: Is the check result normal?

YES : .

Go to Step 3.

NO : .

Repair the harness wire between SRS-ECU

connector B-35 (terminal Nos.7 and 8) and
driver’s seat belt pre-tensioner connector
C-28 (terminal Nos.1 and 2).

STEP 3. Check whether the diagnosis code is
reset.

Q: Is diagnosis code 67 set?

YES :

Replace the SRS-ECU (Refer to

P.52B-143

).

NO :

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

P.00-13

).

Code No.68: Passenger's (front) seat belt pre-tensioner (squib) system (short-circuited to the power
supply)

13 14

16 17

19 20

5 6 7 8 9 10 11 12

1 2

3 4

18

15

AC208915

B-35 Harness side
connector (rear view)

AE

AC510233

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

SEAT BELT
PRETENSIONER
(LH)

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

NOTE

: CONNECTOR COUPLED: ON
CONNECTOR UNCOUPLED: OFF

Passenger's (Front) Seat Belt Pre-tensioner (Squib)

AB

Main

Index

Group

TOC

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-100

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 pre-tensioner will deploy.

DIAGNOSIS CODE SET CONDITIONS

This diagnosis code is set if passenger's (front) seat
belt pre-tensioner wire(s) are short-circuited to the
power supply.

PROBABLE CAUSES

• Damaged wiring harnesses or connectors

• Short to the power supply in the passenger's

(front) seat belt pre-tensioner (squib) harness

• Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

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

(2) Disconnect passenger's (front) seat belt

pre-tensioner connector C-20. Use a flat-tipped
screwdriver to pull out the locking button at the
harness side connector, and then disconnect the
connector.

(3) Connect special tool dummy resistor (MB991865)

to special tool resistor harness (MB991884).

(4) Connect special tool (MB991884) to the C-20

harness side connector.

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

the diagnosis code.

Q: Is diagnosis code 68 set?

YES :

Go to Step 2.

NO :

Replace the passenger's (front) seat belt
pre-tensioner (Refer to

P.52B-159

).

AC207223 AE

Harness side
connector
(front view)

Connector: C-20

C-20 (B)

Centre

pillar

AC208430AE

Pre-tensioner

connector

Locking

button

Harness side

connector

Flat-tipped

screwdriver

AC201287BQ

C-20

Harness side
connector

MB991884

Main

Index

Group

TOC

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-101

STEP 2. Voltage measurement at the SRS-ECU
connector B-35.
(1) Disconnect the negative battery terminal.

(2) Disconnect SRS-ECU connector B-35.

DANGER

To prevents the air bag from deploying unin-
tentionally, disconnect the passenger's
(front) seat belt pre-tensioner connector C-20
to short the squib circuit.

(3) Disconnect passenger's (front) seat belt

pre-tensioner connector C-20. Use a flat-tipped
screwdriver to pull out the locking button at the
harness side connector, and then disconnect the
connector.

(4) Connect the negative battery terminal.
(5) Turn the ignition switch to the "ON" position,

CAUTION

Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.
(6) Voltage measurement between B-35 harness

side connector terminals 5, 6 and body earth.

OK: 0 V

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Repair the harness wires between
SRS-ECU connector B-35 (terminal No.5
and 6) and passenger's (front) seat belt
pre-tensioner connector C-20 (terminal No.1
and 2).

STEP 3. Check whether the diagnosis code is
reset.

Q: Is diagnosis code 68 set?

YES :

Replace the SRS-ECU (Refer to

P.52B-143

).

NO :

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

P.00-13

).

AC206285

AF

B-35 (Y)

Connector: B-35

Harness side
connector
(rear view)

AC207223 AE

Harness side
connector
(front view)

Connector: C-20

C-20 (B)

Centre

pillar

AC208430AE

Pre-tensioner

connector

Locking

button

Harness side

connector

Flat-tipped

screwdriver

13 14

16 17

19 20

5 6 7 8 9 10 11 12

1 2

3 4

18

15

AC208912

B-35
Harness side connector
(rear view)

AE

Main

Index

Group

TOC