Mitsubishi Colt Ralliart. Manual — part 555

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-58

STEP 4. 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 then check

the diagnosis code.

Q: Is diagnosis code 26 set?

YES :

Go to Step 5.

NO :

Replace the driver's seat belt with
pre-tensioner (Refer to

P.52B-159

).

STEP 5. 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-59

CAUTION

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

between terminals 7, 8 and the short spring to
release the short spring.

CAUTION

Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.

(5) Resistance measurement between B-35 harness

side connector terminals 7 and 8.

OK: Open circuit

Q: Is the check result normal?

YES : .

Go to Step 6.

NO : .

Repair the harness wires between

SRS-ECU connector B-35 (terminal No.7
and 8) and driver’s seat belt pre-tensioner
connector C-28 (terminal No.1 and 2).

STEP 6. Check whether the diagnosis code is
reset.

Q: Is diagnosis code 26 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

).

AC208509

Section
A - A

B-35
Harness side connector
(front view)

Cable tie

Short spring

Terminal

AE

4 mm or more

A

A

13 14

16 17

19 20

5 6 7 8 9 10 11 12

1 2

3 4

18

15

AC208505

B-35Harness side connector
(rear view)

AE

Main

Index

Group

TOC

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-60

Code No.27: Driver's seat belt pre-tensioner (squib) system (open-circuited in the squib circuit)

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 driver's seat belt pre-ten-
sioner squib wire(s) are open-circuited. However, if
no diagnosis code resets, the SRS warning lamp will
be switched off (diagnosis code will be retained).

PROBABLE CAUSES

• Improper connector contact

• Open circuit in the driver's seat belt pre-tensioner

(squib) circuit

• Malfunction of the SRS-ECU

AC510230

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
(RH)

SRS-ECU

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

NOTE

: CONNECTOR COUPLED: ON
CONNECTOR UNCOUPLED: OFF

Driver's Seat Belt Pre-Tensioner (Squib)

AB

Main

Index

Group

TOC

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-61

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 then check

the diagnosis code.

Q: Is diagnosis code 27 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 between
SRS-ECU connector B-35 (terminal No.7 and 8)
and the driver's seat belt pre-tensioner C-28
(terminal No.2 and 1).
(1) Disconnect the negative battery terminal.

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

driver's seat belt pre-tensioner connector C-28,
and measure at the wiring harness side. For
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