Mitsubishi Lancer Evolution IX. Manual - part 639

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-69

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

CONNECTOR
LOCK
SWITCH

CLOCK
SPRING

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

AIR BAG
DRIVE CIRCUIT

SRS-ECU

MICROCOMPUTER

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

NOTE

: CONNECTOR
COUPLED: ON
CONNECTOR
UNCOUPLED: OFF

Driver's Air Bag Module (Squib) Circuit

: LH drive vehicles
: RH drive vehicles

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-70

DIAGNOSIS PROCEDURE

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

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

module connector C-201 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 C-201 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-110

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

(2) Disconnect the clock spring connector C-205.

(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 C-205 (terminal No.3 and
4) by backprobing.

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

diagnosis code.

AC105823

AC304700

AC305145AE

Steering
wheel

C-201 Air bag
module connector

AC300945AE

MB991865
(Dummy resistor : 3 )

MB991866
(Resistor harness)

C-201 Air bag
module
connector

AC310479

Connector: C-205 <LHD>

C-205 (Y)

Harness side
connector
(rear view)

AC310481AG

Connector: C-205 <RHD>

C-205 (Y)

Harness side
connector
(rear view)

AC300949AC

MB991865 (Dummy
resistor : 3 )

MB991866
(Resistor harness)

C-205 Clock spring
connector

(Rear view)

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-71

Q: Is diagnosis code 61 set?

YES :

Go to Step 3.

NO :

Replace the clock spring (Refer to

P.52B-110

STEP 3. Voltage measurement at the SRS-ECU
connector C-12

(1) Disconnect SRS-ECU connector C-12.

DANGER

To prevents the air bag from deploying unin-
tentionally, disconnect the clock spring con-
nector C-205 to short the squib circuit.

(2) Disconnect the clock spring connector C-205.

(3) 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.
(4) Voltage measurement between C-12 harness

side connector terminals 11, 12 and body earth.

OK: 0 V

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Repair the harness wires between
SRS-ECU connector C-12 (terminal No.11
and 12) and clock spring connector C-205
(terminal No.3 and 4).

STEP 4. Check whether the diagnosis code is
reset.

Q: Is diagnosis code 61 set?

YES :

Replace the SRS-ECU (Refer to

P.52B-109

NO :

An intermittent malfunction is suspected
(Refer to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points

P.00-5

AC101950AJ

SRS-ECU

Harness side
connector
(rear view)

C-12 (Y)

Connector: C-12

AC310479

Connector: C-205 <LHD>

C-205 (Y)

Harness side
connector
(rear view)

AC310481AG

Connector: C-205 <RHD>

C-205 (Y)

Harness side
connector
(rear view)

AC006255

13 14 15 16 17 18 19 20

5 6 7 8 9 10 11 12

1 2

3 4

C-12 Harness side
connector (rear view)

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-72

Code No.62: Driver's air bag module (squib) system (short-circuited to the earth)

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 outputs 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 earth.

PROBABLE CAUSES

• Malfunction of the clock spring

• Damaged harness wires and connectors

• Short to the earth in the driver's air bag module

(squib) harness

• Malfunction of the SRS-ECU

CONNECTOR
LOCK
SWITCH

CLOCK
SPRING

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

AIR BAG
DRIVE CIRCUIT

SRS-ECU

MICROCOMPUTER

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

NOTE

: CONNECTOR
COUPLED: ON
CONNECTOR
UNCOUPLED: OFF

Driver's Air Bag Module (Squib) Circuit

: LH drive vehicles
: RH drive vehicles

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