Mitsubishi Lancer Evolution IX. Manual — part 631

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-37

STEP 2. Resistance measurement between
SRS-ECU connector C-13 (terminal No.29 and 30)
and the driver's seat belt pre-tensioner D-16
<LHD> or D-03 <RHD> (terminal No.2 and 1).

(1) Disconnect SRS-ECU connector C-13 and

driver's seat belt pre-tensioner connector D-16

<LHD> or D-03 <RHD>, and measure at the
wiring harness side. For connector D-16 <LHD>
or D-03 <RHD>, use a flat-tipped screwdriver to
pull out the locking button at the harness side
connector, and then disconnect the connector.

(2) Connect D-16 <LHD> or D-03 <RHD> harness

side connector to special tool resistor harness
(MB991884).

CAUTION

Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.
(3) Resistance measurement between the following

terminals.

• SRS-ECU connector C-13 terminal No.29 and

special tool terminal No.1

• SRS-ECU connector C-13 terminal No.30 and

special tool terminal No.2

OK: Less than 2

Ω

Q: Are the check results normal?

YES :

Go to Step 3.

NO :

Repair the harness wires between
SRS-ECU connector C-13 (terminal No.29
and 30) and driver’s seat belt pre-tensioner
connector D-16 <LHD> or D-03 <RHD>
(terminal No.2 and 1).

AC101951

Connector: C-13

SRS-ECU

AL

C-13 (Y)

21

252627 282930 313233
34 35 3637 38394041 42

22

23 24

Harness side
connector
(rear view)

AC310465

AN

Connector: D-16
<LHD>

Harness side
connector
(front view)

D-16 (B)

AC310471

Ai

Connector: D-03
<RHD>

Harness side
connector
(front view)

D-03 (B)

AC300147AW

Flat-tipped
screwdriver

Locking button

D-16 <LHD>,
D-03 <RHD>
Driver's seat
belt pre-tensioner
connector

D-16 <LHD>, D-03 <RHD>
Harness side connector

AC201287AZ

MB991884

D-16 <LHD>,
D-03 <RHD>
Harness side
connectors

AC203780

34 35 36 37 38 39 40 41 42

25 26 27 28 29 30 31 32 33

21 22

23 24

2

1

C-13 Harness side
connector
(rear view)

Special tool
MB991884

AE

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-38

STEP 3. Check whether the diagnosis code is
reset.

Q: Is diagnosis code No.27 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

).

Code No.28: Passenger's (front) seat belt pre-tensioner (squib) system (short-circuit between
terminals of the squib circuit)

CONNECTOR
LOCK
SWITCH

CONNECTOR
LOCK
SWITCH

AIR BAG DRIVE CIRCUIT

MICROCOMPUTER

SRS-ECU

SEAT BELT
PRE-TENSIONER
(RH)

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

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

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-39

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 seat belt pre-tensioner will
deploy.

DIAGNOSIS CODE SET CONDITIONS

This diagnosis code is set if one passenger’s (front)
seat belt pre-tensioner squib wire shorted to the
other. However, if no diagnosis code resets, the SRS
warning lamp will be switched off (diagnosis code will
be retained).

PROBABLE CAUSES

• Improper engaged connector or defective short

spring*

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

belt pre-tensioner (squib) circuit terminals

• Damaged connector(s)

• 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 disconnected).
Therefore, if connector C-13, D-03 <LHD> or
D-16<RHD> is damaged or improperly engaged, the
short spring may not be released when the connector
is connected.

DIAGNOSIS PROCEDURE

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

CAUTION

To prevent damage to M.U.T.-II/III, always turn the
ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting M.U.T.-II/III.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the diagnosis code is set.
(3) Turn the ignition switch to the "LOOK" (OFF)

position.

CONNECTOR
LOCK
SWITCH

CONNECTOR
LOCK
SWITCH

AIR BAG DRIVE CIRCUIT

MICROCOMPUTER

SRS-ECU

SEAT BELT
PRE-TENSIONER
(LH)

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

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

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-40

Q: Is diagnosis code 34 set?

YES :

Go to Step 2.

NO :

Go to Step 3.

STEP 2. Connector lock check: SRS-ECU
connector C-13. (M.U.T.-II/III diagnosis code)
(1) Disconnect the negative battery terminal.

(2) Disconnect the connectors C-13 and then

reconnect them.

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

diagnosis code.

Q: Is diagnosis code 28 set?

YES :

Go to Step 4.

NO :

The procedure is complete. It is assumed
that diagnosis code 28 set as connector
C-13, D-03 <LHD> or D-16 <RHD> was
engaged improperly.

STEP 3. Connector lock check: SRS-ECU
connector C-13 and passenger’s (front) seat belt
pre-tensioner connector D-03 <LHD> or D-16
<RHD> (M.U.T.-II/III diagnosis code)
(1) Disconnect the negative battery terminal.

(2) Disconnect connectors C-13 and D-03 <LHD> or

D-16 <RHD>, and then reconnect them. For
connector D-03 <LHD> or D-16 <RHD>, use a
flat-tipped screwdriver to pull out the locking
button at the harness side connector, and then
disconnect the connector.

AC101951

Connector: C-13

SRS-ECU

AL

C-13 (Y)

21

252627 282930 313233
34 35 3637 38394041 42

22

23 24

Harness side
connector
(rear view)

AC101951

Connector: C-13

SRS-ECU

AL

C-13 (Y)

21

252627 282930 313233
34 35 3637 38394041 42

22

23 24

Harness side
connector
(rear view)

AC310465

AO

Connector: D-03
<LHD>

Harness side
connector
(front view)

D-03 (B)

AC310471

AJ

Connector: D-16
<RHD>

Harness side
connector
(front view)

D-16 (B)

AC300147AX

Flat-tipped
screwdriver

Locking button

D-03 <LHD>,
D-16 <RHD>
Passenger's (front)
seat belt
pre-tensioner
connector

D-03 <LHD>, D-16 <RHD>
Harness side connector