Mitsubishi Lancer Evolution IX. Manual - part 637

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-61

OPERATION

• Power for the SRS warning lamp is supplied from 

the ignition switch (IG1) circuit.

• 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 diagnosis code is set when an open circuit is 

detected for a continuous period of 5 seconds 
while the SRS-ECU is monitoring the SRS warn-
ing lamp and the lamp is OFF. (transistor OFF). 
However, if the vehicle condition returns to nor-
mal, diagnosis code 43 will be automatically 
erased, and the SRS warning lamp will go out.

PROBABLE CAUSES

• Damaged wiring harnesses of connectors

• Blown bulb

• Malfunction of the SRS-ECU

• Malfunction of the combination meter

DIAGNOSIS PROCEDURE

STEP 1. Check the SRS warning lamp.
(1) Disconnect the negative battery terminal.

(2) Disconnected the SRS-ECU connector C-12.
(3) Connect the negative battery terminal.
(4) Turn the ignition switch to the "ON" position.

Q: Does the warning lamp illuminate?

YES : 

Go to Step 4.

NO : 

Go to Step 2.

STEP 2. Check the SRS warning lamp bulb.

Q: Has the SRS warning lamp bulb blown?

YES : 

Replace the SRS warning lamp bulb.

NO : 

Go to Step 3.

AC101950AJ

SRS-ECU

Harness side 
connector 
(rear view)
 

C-12 (Y)

Connector: C-12

AC311044

SRS warning lamp

AB

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-62

STEP 3. Check the harness for open circuit 
between ignition switch connector C-208 
(terminal No.2) and combination meter C-01 
(terminal No.9) and between combination meter 
C-02 (terminal No.36) and SRS-ECU connector 
C-12 (terminal No.8).

NOTE: After inspecting intermediate connectors 
C-01, C-02, C-23 <LHD> or C-01, C-02 <RHD> 
inspect the wiring harness. If intermediate connec-
tors C-01, C-02, C-23 <LHD> or C-01, C-02 <RHD>. 
are damaged, repair or replace them.

Q: Is the check result normal?

YES : 

Replace the combination meter (Refer to 

GROUP 54A 

− Combination Meters 

Assembly 

P.54A-56

). Then go to Step 4.

NO : 

Repair the harness wires between 
SRS-ECU connector C-12 (terminal No.8) 
and the ignition switch connector C-208 
(terminal No.2). 

AC303806

Connector: C-208
<LHD>

Harness side 
connector 
(front view)

AI

Clock spring

AC303820 AE

Connector: C-208
<RHD>

Harness side 
connector 
(front view)

Clock spring

AC303799

Connectors: C-01, C-02, C-23

AQ

C-01

<LHD>

C-01

Harness side

C-02 (L)

C-23 (B)

C-02

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

C-23

2

1

3

13

12

14

21

10

5

4

6

16

15

17

7 8 9

19

18

20

11

22

Harness side

AC303815

Connectors: C-01, C-02

AR

<RHD>

C-01
Harness side

C-02 
Harness side

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

C-01

C-02(L)

AC101950AJ

SRS-ECU

Harness side 
connector 
(rear view)
 

C-12 (Y)

Connector: C-12

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-63

STEP 4. Check whether the diagnosis code is 
reset.

Q: Is diagnosis code 43 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

). 

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-64

Code No.43: SRS warning lamp circuit open-circuited (Lamp does not Switch Off).

IGNITION
SWITCH (IG1)

MICROCOMPUTER

COMBINATION
METER

WARNING LAMP
DRIVE CIRCUIT

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 : Gray     R : Red     P : Pink     V : Violet

SRS Warning Lamp Drive Circuit

CONNECTOR
LOCK SWITCH

NOTE

: CONNECTOR
  COUPLED: ON
  CONNECTOR
  UNCOUPLED: OFF

: LH drive  vehicles
: RH drive  vehicles