Mitsubishi Lancer Evolution IX. Manual — part 625

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-13

Step 2. Resistance measurement at the SRS-ECU
connector C-12.

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

CAUTION

Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.
(2) Take the measurements below at harness-side

connector C-12.

• Resistance between terminals 1 and 2 as well

as 3 and 4.

NG: 2 ohms or less (short circuit) or 2
megaohms or more (open circuit)

• Continuity between terminals 1, 2, 3, 4 and

body earth

OK: No continuity

Q: Is the check result satisfactory?

YES :

Go to Step 3.

NO :

Go to Step 4.

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

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

CAUTION

Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.
(2) Take the measurements below at harness-side

connector C-12.

• Voltage between terminals 1, 2, 3, 4 and body

earth

OK: 0V

Q: Is the check result satisfactory?

YES :

Go to Step 5.

NO :

Go to Step 4.

AC101950AJ

SRS-ECU

Harness side
connector
(rear view)

C-12 (Y)

Connector: C-12

AC100338

AC103684

1314151617181920

5 6 7 8 9 101112

1 2

3 4

AC103683 AK

C-12 Harness side
(Rear View)

AC100338

1314151617181920

5 6 7 8 9 101112

1 2

3 4

AC103684 AK

C-12 Harness side
(Rear View)

AC103372

4

1

2

3

5

7

6

8

16

15

14

13

12

11

10

9

20

19

18

17

AI

C-12 Harness side
(Rear View)

AC101950AJ

SRS-ECU

Harness side
connector
(rear view)

C-12 (Y)

Connector: C-12

4

1

2

3

5

7

6

8

16

15

14

13

12

11

10

9

20

19

18

17

AC210613

C-12 Harness side
(Rear View)

AB

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-14

Step 4. Check the wiring harness between the
right front impact sensor connector A-37
(terminals 1 and 2) and SRS-ECU connector C-12
(terminals 1 and 2) as well as between left front
impact sensor connector A-33 (terminals 1 and 2)
and SRS-ECU connector C-12 (terminals 3 and 4).

NOTE:

AC310431

Connector: A-37 <LHD>

AF

Harness side
(front view)

A-37 (Y)

2

1

AC310433

Connector: A-37 <RHD>

AE

Harness side
(front view)

A-37 (Y)

2

1

AC101950AJ

SRS-ECU

Harness side
connector
(rear view)

C-12 (Y)

Connector: C-12

AC310542

Connectors: A-33 <LHD>

AE

A-33 (Y)

Harness side
(front view)

2

1

AC310475

Connector: A-33 <RHD>

AD

A-33 (Y)

Harness side
(front view)

2

1

AC310452

AW

Connector: C-111
<LHD>

AC310456

Connector: C-111

AT

<RHD>

AC310446

Connector: C-129 <LHD>

BD

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-15

Prior to the wiring harness inspection, check interme-
diate connectors C-111 and C-129, and repair if nec-
essary.

• Check the front impact sensor output line for

open or short circuit.

Q: Is the check result satisfactory?

YES :

Go to Step 4.

NO :

Repair the wiring harness.

Step 5. Check whether the diagnosis code is
reset.
Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the diagnosis code is set.
(4) Turn the ignition switch to the "LOCK" (OFF)

position.

Q: Is diagnosis code 1A, 1B, 1C, 1D, 2A, 2B, 2C or 2D

set?
YES :

Replace the SRS-ECU (Refer to

P.52B-109

).

NO :

The procedure is complete. (If no
malfunctions are found in all steps, an
intermittent malfunction is suspected. Refer
to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points

P.00-5

).

Code No.14: Analogue G-sensor malfunction

Code No.15: Safing G-sensor (for frontal collision) short-circuited

Code No.16: Safing G-sensor (for frontal collision) open-circuited

Code No.31: SRS-ECU capacitor circuit voltage too high

Code No.32: SRS-ECU capacitor circuit voltage too low

Code No.45: SRS-ECU non-volatile memory (EEPROM) and A/D converter system

Code No.51: Driver's air bag squib activating circuit short-circuited

Code No.52: Driver's air bag squib activating circuit open-circuited

Code No.54: Passenger's (front) air bag squib activating circuit short-circuited

Code No.55: Passenger's (front) air bag squib activating circuit open-circuited

Code No.56: Driver’s seat belt pre-tensioner activating circuit short-circuited

Code No.57: Driver’s seat belt pre-tensioner activating circuit open-circuited

Code No.58: Passenger’s (front) seat belt pre-tensioner activating circuit short-circuited

Code No.59: Passenger’s (front) seat belt pre-tensioner activating circuit open-circuited

AC310454

Connector: C-129 <RHD>

AV

TROUBLESHOOTING

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-16

DIAGNOSIS CODE SET CONDITIONS

These diagnosis codes are set when a fault is
detected in the SRS-ECU. The most likely causes for
this code to be set are shown in the table below:

PROBABLE CAUSE

Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

Replace the SRS-ECU (Refer to

P.52B-109

).

Code No.

Part/Circuit integral to
SRS-ECU

Trouble causes

14

Analog G-sensor

• When the analog G-sensor is not operating

• When the characteristics of the analog G-sensor are

abnormal

• When the output from the analog G-sensor is

abnormal

15

Safing G-sensor (for frontal
collision)

• Short circuit in the safing G-sensor

16

• Open circuit in the safing G-sensor

31

Capacitor circuit

• Voltage at the capacitor terminal is higher than the

specified value for five seconds or more

32

• Voltage at the capacitor terminal is lower than the

specified value for five seconds or more (This is not
detected if diagnosis code No.41 or 42 indicating
battery positive voltage drop has been output).

45

Non-volatile memory (EEPROM)
and A/D converter

• When the non-volatile memory (EEPROM) and A/D

converter system are abnormal

51

Driver's air bag module (squib
ignition drive circuit)

• Short circuit in the squib ignition drive circuit

52

• Open circuit in the squib ignition drive circuit

54

Passenger's (front) air bag
module (squib ignition drive
circuit)

• Short circuit in the squib ignition drive circuit

55

• Open circuit in the squib ignition drive circuit

56

Driver’s seat belt pre-tensioner
(squib ignition drive circuit)

• Short circuit in the squib ignition drive circuit

57

• Open circuit in the squib ignition drive circuit

58

Passenger’s (front) seat belt
pre-tensioner (squib ignition drive
circuit)

• Short circuit in the squib ignition drive circuit

59

• Open circuit in the squib ignition drive circuit