Subaru Legacy IV (2008 year). Manual - part 1012

AB(diag)-36

Airbag Warning Light Failure

AIRBAG SYSTEM (DIAGNOSTICS)

B: AIRBAG WARNING LIGHT REMAINS OFF

DETECTING CONDITION:
• Fuse No. 5 (in fuse box) is blown out.
• Body harness circuit is open.
• Airbag warning light is faulty.
• Airbag main harness is faulty.
• Airbag control module is faulty.

CAUTION:
• Before diagnosing the airbag system, be sure to turn the ignition switch to OFF, disconnect the
ground cable from the battery, and wait 20 seconds or more before starting to work.
• When replacing the airbag module, seat belt pretensioner, roll connector, control module and sen-
sor, reconnect each part and check that the warning light operates properly.
• When inspecting the airbag main harness, disconnect the airbag module connectors of the driver’s
and passenger’s seats for safety.
• When inspecting the airbag rear harness, disconnect the side airbag module connector, curtain
airbag module connector and seat belt pretensioner connector for safety reasons.
WIRING DIAGRAM:

AB6

B31

AB1

No.5

11

A3

AB6

AB1

i10

B36

i1

i1

3

14

1 2

3 4

5 6 7 8 9 10

16

11

15

14

13

12

17

19

18

23

25

24

20

22

21

26

28

27

2

1

3 4

6 7 8 9 10

22

21

20

19

18

17

16

15

14

13

12

11

5

*

*

: WITHOUT MID MODEL : A13

: WITH MID MODEL

: B14 

i10

A:

i11

B:

1 2 3

4 5 6

7 8 9 10 11 12 13 14

i11

B:

A:

AB-01760

18 19 20

21 22 23 24 25 26 27 28

1 2 3

5 6 7 8

10

9

4

11 12 13 14

16 17

15

29 30

1 2

3 4

5 6 7 8 9 10

E

E

26

25

IGNITION SWITCH

AIRB

A

G

 W

ARNING 

LIGHT

REVERSE

CIRCUIT

COMBINATION METER

BATTERY

AIRBAG CONTROL MODULE

AB(diag)-37

Airbag Warning Light Failure

AIRBAG SYSTEM (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK COMBINATION METER.
Turn the ignition switch to ON, and confirm that 
warning lights of combination meter illuminate.

Do warning lights except for air-
bag illuminate?

Go to step 2.

Check the combi-
nation meter.

2

CHECK DTC.
Read the DTC. <Ref. to AB(diag)-24, READ 
DIAGNOSTIC TROUBLE CODE (DTC), 
OPERATION, Subaru Select Monitor.>

Is DTC displayed?

Perform the diag-
nosis according to 
DTC.

Go to step 3.

3

CHECK FUSE NO. 5 (IN MAIN FUSE BOX).
Remove the fuse No. 5 and perform visual 
inspection.

Is fuse No. 5 (in the main fuse 
box) blown out?

Replace the fuse 
No. 5. If the fuse 
No. 5 is blown out 
again, go to step 4.

Go to step 4.

4

CHECK AIRBAG WARNING LIGHT CIRCUIT 
(IN COMBINATION METER).
1) Turn the ignition switch to OFF, disconnect 
the battery ground cable, and wait for 20 sec-
onds or more.
2) Disconnect the connectors (AB1) and 
(B31).
3) Connect the battery ground terminal and 
turn the ignition switch to ON.

Does airbag warning light illu-
minate?

Go to step 5.

Check the combi-
nation meter.

5

CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect 
the battery ground cable, and wait for 20 sec-
onds or more.
2) Connect the connector (AB1) and (B31).
3) Disconnect the connectors (AB6, AB17, 
AB18) from airbag control module.
4) Connect the battery ground terminal and 
turn the ignition switch to ON.

Does airbag warning light illu-
minate?

Replace the airbag 
control module. 
<Ref. to AB-20, 
Airbag Control 
Module.>

Replace the airbag 
main harness 
along with bulk-
head harness.

AB(diag)-38

List of Diagnostic Trouble Code (DTC)

AIRBAG SYSTEM (DIAGNOSTICS)

13.List of Diagnostic Trouble Code (DTC)

A: LIST

DTC

Display

Content of diagnosis

Reference

11

Driver’s Airbag failure

• Airbag main harness circuit is open, shorted or 
shorted to ground.
• Airbag module harness (Driver’s side) circuit is 
open, shorted or shorted to ground.
• Roll connector circuit is open, shorted or shorted to 
ground.
• Airbag control module is faulty.
• Driver’s airbag module is faulty.

<Ref. to AB(diag)-46, 
DTC 11 DRIVER’S AIR-
BAG FAILURE, Diag-
nostic Chart with Trouble 
Code.>

12

Passenger’s Airbag failure

• Airbag main harness circuit is open, shorted or 
shorted to ground.
• Airbag module harness (Passenger’s side) circuit is 
open, shorted or shorted to ground.
• Airbag control module is faulty.
• Passenger’s airbag module is faulty.

<Ref. to AB(diag)-49, 
DTC 12 PASSENGER’S 
AIRBAG FAILURE, 
Diagnostic Chart with 
Trouble Code.>

15

Driver’s Airbag failure

• Airbag main harness circuit (Driver’s side) is 
shorted to power supply.
• Airbag module harness circuit (Driver’s side) is 
shorted to power supply.
• Roll connector is shorted to power supply.
• Airbag control module is faulty.
• Driver’s airbag module is faulty.

<Ref. to AB(diag)-51, 
DTC 15 DRIVER’S AIR-
BAG FAILURE, Diag-
nostic Chart with Trouble 
Code.>

16

Passenger’s Airbag failure

• Airbag main harness circuit (Passenger’s side) is 
shorted to power supply.
• Airbag module harness circuit (Passenger’s side) is 
shorted to power supply.
• Airbag control module is faulty.
• Passenger’s airbag module is faulty.

<Ref. to AB(diag)-54, 
DTC 16 PASSENGER’S 
AIRBAG FAILURE, 
Diagnostic Chart with 
Trouble Code.>

21

Airbag ECU failure

Airbag control module is faulty.

<Ref. to AB(diag)-56, 
DTC 21 AIRBAG ECM 
FAILURE, Diagnostic 
Chart with Trouble 
Code.>

22

Front Airbag: Firing output

Front airbag module and seat belt pretensioner (LH/
RH) are inflated.

<Ref. to AB(diag)-57, 
DTC 22 FRONT AIR-
BAG FIRING OUTPUT, 
Diagnostic Chart with 
Trouble Code.>

26

Passenger's Airbag indicator failure

• Passenger’s airbag indicator is faulty.
• Airbag control module is faulty.
• Airbag main harness circuit is open, shorted or 
shorted to ground.
• Body harness circuit is open.

<Ref. to AB(diag)-58, 
DTC 26 PASSENGER’S 
AIRBAG INDICATOR 
FAILURE, Diagnostic 
Chart with Trouble 
Code.>

27

ODS Communication error

• Occupant detection control module communication 
is faulty.
• Airbag rear harness circuit is open, shorted, 
shorted to ground or shorted to power supply.
• Occupant detection harness is faulty.
• Airbag control module is faulty.
• Occupant detection system is faulty.

<Ref. to AB(diag)-60, 
DTC 27 ODS COMMU-
NICATION ERROR, 
Diagnostic Chart with 
Trouble Code.>

AB(diag)-39

List of Diagnostic Trouble Code (DTC)

AIRBAG SYSTEM (DIAGNOSTICS)

29

ODS failure

• Occupant detection sensor is faulty.
• Occupant detection control module is faulty.
• Occupant detection harness is faulty.
• Fuse No. 25 (in joint box) is blown.

Refer to “Occupant 
Detection System” for 
details on DTC 29. <Ref. 
to OD(diag)-26, DTC 29 
ODS FAILURE, Diag-
nostic Procedure with 
Diagnostic Trouble Code 
(DTC).>

2A

ODS Calibration error

System calibration (Rezeroing) of the occupant detec-
tion system was not ended normally.

Refer to “Occupant 
Detection System” for 
details on DTC 2A. <Ref. 
to OD(diag)-23, DTC 2A 
ODS CALIBRATION 
ERROR, Diagnostic Pro-
cedure with Diagnostic 
Trouble Code (DTC).>

2B

ODS System wrong parts

• Wrong airbag control module was installed.
• Wrong occupant detection system was installed.
• Occupant detection system is faulty.

Refer to “Occupant 
Detection System” for 
details on DTC 2B. <Ref. 
to OD(diag)-23, DTC 2B 
ODS SYSTEM WRONG 
PARTS, Diagnostic Pro-
cedure with Diagnostic 
Trouble Code (DTC).>

2C

Belt tension Sensor failure

• Passenger’s seat belt tension sensor is faulty.
• Occupant detection system is faulty.
• Airbag rear harness circuit is open, shorted, 
shorted to ground or shorted to power supply.
• Occupant detection harness is faulty.

Refer to “Occupant 
Detection System” for 
details on DTC 2C. <Ref. 
to OD(diag)-24, DTC 2C 
BELT TENSION SEN-
SOR FAILURE, Diag-
nostic Procedure with 
Diagnostic Trouble Code 
(DTC).>

33

FrontSubSensor RH failure

Front sub sensor (RH) is faulty.

<Ref. to AB(diag)-61, 
DTC 33 FRONT SUB 
SENSOR RH FAILURE, 
Diagnostic Chart with 
Trouble Code.>

34

FrontSubSensor LH failure

Front sub sensor (LH) is faulty.

<Ref. to AB(diag)-61, 
DTC 34 FRONT SUB 
SENSOR LH FAILURE, 
Diagnostic Chart with 
Trouble Code.>

37

Buckle Switch RH failure

• Passenger’s buckle switch circuit is open, shorted 
or shorted to ground.
• Occupant detection system is faulty.
• Occupant detection harness is faulty.

Refer to “Occupant 
Detection System” for 
details on DTC 37. <Ref. 
to OD(diag)-27, DTC 37 
BUCKLE SWITCH RH 
FAILURE, Diagnostic 
Procedure with Diagnos-
tic Trouble Code (DTC).>

39

Seatbelt Warning failure

• Airbag control module is faulty.
• Body integrated unit is faulty.
• Harness circuits between body integrated unit and 
airbag control module are open, shorted or shorted to 
ground.

<Ref. to AB(diag)-62, 
DTC 39 SEAT BELT 
WARNING FAILURE, 
Diagnostic Chart with 
Trouble Code.>

DTC

Display

Content of diagnosis

Reference