Mitsubishi Lancer Evolution IX. Manual - part 629

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-29

(3) Resistance measurement between the following 

terminals. 

• SRS-ECU connector C-12 terminal No.10 and 

the passenger’s (front) air bag module con-
nector C-106 terminal No.1

• SRS-ECU connector C-12 terminal No.9 and 

the passenger’s (front) air bag module con-
nector C-106 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-12 (terminal No.10 
and 9 and passenger’s (front) air bag 
module connector C-106 (terminal No.1 and 
2).

STEP 3. Check whether the diagnosis code is 
reset.

Q: Is diagnosis code 25 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.26: Driver's seat belt pre-tensioner (squib) system (short-circuited between terminals of the 
squib circuit) 

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

Driver's Seat Belt Pre-Tensioner (Squib) (LHD)

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-30

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 driver’s seat belt 
pre-tensioner squib wire shorted to the other. How-
ever, 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 driver's 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-16 <LHD>, or D-03 
<RHD> is damaged or improperly engaged, the short 
spring may not be released when the connector is 
connected.

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

Driver's Seat Belt Pre-Tensioner (Squib) (RHD)

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-31

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.

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 26 set?

YES : 

Go to Step 4.

NO : 

The procedure is complete. It is assumed 
that diagnosis code 26 set as connector 
C-13 was engaged improperly.

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

(2) Disconnect connectors C-13, D-16 <LHD>, or 

D-03 <RHD>, and then reconnect them. 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.

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

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

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-32

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

diagnosis code.

Q: Is diagnosis code 26 set?

YES : 

Go to Step 4.

NO : 

The procedure is complete. It is assumed 
that diagnosis code 26 set as connector 
C-13, D-16 <LHD>, or D-03 <RHD> was 
engaged improperly.

STEP 4. Check the diagnosis code by connecting 
a dummy resistor. (M.U.T.-II/III diagnosis code)
(1) Disconnect the negative battery terminal.

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

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.

(3) Connect special tool dummy resistor (MB991865) 

to special tool resistor harness (MB991884).

(4) Connect special tool (MB991884) to the 

D-16<LHD> or D-03 <RHD> 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-117

).

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

MB991884
MB991885

AC300975 AI

MB991865
(Dummy resistor : 3  )

MB991884
(Resistor
harness)

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