Mitsubishi Colt Ralliart. Manual — part 561

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-82

TROUBLESHOOTING HINTS

• Damaged wiring harnesses of connectors

• Malfunction of the SRS-ECU

• Malfunction of the combination meter

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III actuator test.
Use M.U.T.-III to perform the combination meter
actuator tests.

• Item No.A0: Illuminate the indicator lamp and the

warning lamp.

• Item No.A1: Extinguish the indicator lamps and

the warning lamps.

Q: Does the warning lamp illuminate/extinguish?

YES :

Go to Step 2.

NO :

Replace the combination meter (Refer to
GROUP 54A, Combination Meters
Assembly

P.54A-67

).

STEP 2. Check the harness for open circuit to
earth between SRS-ECU connector B-35
(terminal No.18) and combination meter
connector B-14 (terminal No.26).

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Repair the harness wire between SRS-ECU
connector B-35 (terminal No.18) and
combination meter connector B-14 (terminal
No.26).

STEP 3. Check whether the diagnosis code is
reset.

Q: Is diagnosis code 43 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)

AC313822 AP

Connector: B-14

Harness side
connector
(rear view)

B-14 (B)

Main

Index

Group

TOC

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-83

Code No.44: SRS warning lamp circuit malfunction

OPERATION

• Power for the SRS warning lamp is supplied from

the ignition switch (IG1).

• The SRS warning lamp illuminates when the igni-

tion switch is turned to the "ON" position and
goes out after approximately 7 seconds if there is
not a malfunction in the SRS system.

DIAGNOSIS CODE SET CONDITIONS

This code will be set if the SRS warning lamp driving
circuit is short or the transistor failure in the
SRS-ECU is detected. However, if the system
returns to normal condition, code No.44 will be
erased automatically and the SRS warning lamp will
go out.

AC510235

IGNITION
SWITCH (IG1)

COMBINATION
METER

METER
AND
A/C-ECU

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

SRS Warning Lamp Drive Circuit

AB

Main

Index

Group

TOC

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-84

PROBABLE CAUSES

• Damaged wiring harnesses of connectors

• Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

Check the SRS warning lamp drive circuit system.
Refer to

P.52B-78

.

Code No.61: Driver's air bag module (squib) system (short-circuited to the power supply)

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

via the clock spring to inflate the air bag.

DIAGNOSIS CODE SET CONDITIONS

This diagnosis code is set if the driver’s air bag squib
wire(s) are short-circuited to the power supply.

PROBABLE CAUSES

• Malfunction of the clock spring

• Damaged harness wires and connectors

• Short to the power supply in the driver's air bag

module (squib) harness

• Malfunction of the SRS-ECU

AC510223

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

AIR BAG MODULE
(SQUIB)
(DRIVER'S SIDE)

CONNECTOR
LOCK SWITCH

CONNECTOR
LOCK SWITCH

CLOCK
SPRING

SRS-ECU

CONNECTOR
LOCK SWITCH

NOTE

: CONNECTOR COUPLED: ON
CONNECTOR UNCOUPLED: OFF

Driver's Air Bag Module (Squib) Circuit

AB

Main

Index

Group

TOC

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-85

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) By sliding the A section (in the figure) of air bag

module connector B-138 in arrow direction,
disconnect the 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 clock spring

side air bag module connector B-138 by
backprobing.

(5) Connect the negative battery terminal.

(6) Erase the diagnosis code memory, and check the

diagnosis code.

Q: Is diagnosis code 61 out put?

YES :

Go to Step 2.

NO :

Replace the driver’s air bag module (Refer
to

P.52B-145

).

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

(2) Disconnect the clock spring connector B-136.

(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 clock spring

harness side connector B-136 (terminal No.3 and
4) by backprobing.

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

diagnosis code.

Q: Is diagnosis code 61 set?

YES :

Go to Step 3.

NO :

Replace the clock spring (Refer to

P.52B-145

).

AC105823

AC304700

AC305145AF

A

Steering
wheel

B-138 Air bag
module connector

AC300945AG

MB991865
(Dummy resistor : 3

Ω)

MB991866
(Resistor harness)

B-138 Air bag
module
connector

AC313828 AF

Connectors: B-136

B-136

Harness side
connector
(rear view)

AC300949 AF

MB991865 (Dummy
resistor : 3

Ω)

MB991866
(Resistor harness)

B-136 Clock spring
connector

(Rear view)

Main

Index

Group

TOC