Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 624

AB(diag)-35

Airbag Warning Light Failure

AIRBAG SYSTEM (DIAGNOSTICS)

12.Airbag Warning Light Failure

A: AIRBAG WARNING LIGHT REMAINS ON

DETECTING CONDITION:

• Airbag warning light is faulty.

• Airbag control module to airbag warning light circuit is shorted or open.

• Grounding circuit is faulty.

• Airbag control module is faulty.

• Connector connection is improper.

• Connections of (AB6, AB17, AB18) to airbag control module are improper.
CAUTION:

• Before diagnosing the airbag system, be sure to turn the ignition switch to OFF, disconnect the

ground cable from battery, and wait 60 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:

Airbag system <Ref. to WI-82, WIRING DIAGRAM, Airbag System.>

Step

Check

Yes

No

1

READ DTC.
Read the DTC. <Ref. to AB(diag)-26, READ
DIAGNOSTIC TROUBLE CODE (DTC),
OPERATION, Subaru Select Monitor.>

Is DTC displayed?

Go to step

2.

Go to step

3.

2

CHECK DTC.

Is the displayed DTC 2D?

Go to step

3.

Perform the diag-
nosis according to
DTC.

AB6

B31

AB1

No.5

11

2

i10

B38

i3

i3

5

18

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

IGNITION

SWITCH

COMBINATION METER

B

A

TTER

Y

AIRB

A

G

W

ARNING

LIGHT

AIRBAG CONTROL MODULE

REVERSE

CIRCUIT

i10

AB-02240

E

E

26

25

36

B31

1

2

3 4 5 6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

AB6

18 19 20

21 22 23 24 25 26 27 28

1 2 3 4 5

11

10

12 13 14

16 17

15

29 30

6 7 8 9

AB(diag)-36

Airbag Warning Light Failure

AIRBAG SYSTEM (DIAGNOSTICS)

3

CHECK FOR POOR CONTACT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Check that the airbag control module and
the connectors (AB6, AB17, AB18) are securely
connected.

Are there poor contact of con-
nectors (AB6, AB17, AB18)?

If the faulty con-
nector contact
remains, replace
the airbag main
harness along with
body harness or
replace the airbag
control module.
<Ref. to AB-21,
Airbag Control
Module.>

Go to step

4.

4

CHECK AIRBAG MAIN HARNESS.
1) Remove the instrument panel lower cover
and disconnect the connectors (AB7) and
(AB2).
2) Remove the console front panel and discon-
nect the connector (AB9).
3) Disconnect the connectors (AB6, AB17,
AB18) from the airbag control module, and con-
nect the connector (1AH) in the test harness
AH.
4) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
6) Connect the connectors (7AG) and (8AG) in
the test harness AG.
NOTE:

After the fault has been cleared, disconnect the
connectors (7AG) and (8AG).

Does the airbag warning light
go off?

Go to step

5.

Go to step

6.

5

CHECK GROUND CIRCUIT.
Measure the resistance between connector
(2AG) in the test harness AG and chassis
ground.

Connector & terminal

(2AG) No. 4 — Chassis ground:
(2AG) No. 3 — Chassis ground:

Is the resistance less than 10

Ω?

Replace the airbag
control module.
<Ref. to AB-21,
Airbag Control
Module.>

Repair the chassis
ground circuit.

6

CHECK AIRBAG MAIN HARNESS AND
BULKHEAD HARNESS.
1) Disconnect the connectors (7AG) and
(8AG).
2) Remove the combination meter.
3) Measure the resistance between the combi-
nation meter connector and test harness AG
connector (2AG).

Connector & terminal

(2AG) No. 5 — (i10) No. 36:

Is the resistance less than 10

Ω?

Check the combi-
nation meter.

Go to step

7.

7

CHECK POOR CONTACT OF CONNECTOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground terminal, and wait 60 sec-
onds or more.
2) Confirm that the connectors between the
airbag control module and the combination
meter are securely connected.

Is there poor contact of connec-
tor?

Repair the bulk-
head harness or
replace the airbag
main harness
along with body
harness.

Go to step

8.

8

CHECK AIRBAG MAIN HARNESS.
Check the airbag main harness for defect.

Is there any defect in the airbag
main harness?

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

Repair the bulk-
head harness.

Step

Check

Yes

No

AB(diag)-37

Airbag Warning Light Failure

AIRBAG SYSTEM (DIAGNOSTICS)

B: AIRBAG WARNING LIGHT REMAINS OFF

DETECTING CONDITION:

• Fuse No. 5 (in fuse & relay 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 battery, and wait 60 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:

Airbag system <Ref. to WI-82, WIRING DIAGRAM, Airbag System.>

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)-26, READ
DIAGNOSTIC TROUBLE CODE (DTC),
OPERATION, Subaru Select Monitor.>

Is DTC displayed?

Perform the diag-
nosis according to
DTC.

Go to step

3.

AB6

B31

AB1

No.5

11

2

i10

B38

i3

i3

5

18

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

IGNITION

SWITCH

COMBINATION METER

B

A

TTER

Y

AIRB

A

G

W

ARNING

LIGHT

AIRBAG CONTROL MODULE

REVERSE

CIRCUIT

i10

AB-02240

E

E

26

25

36

B31

1

2

3 4 5 6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

AB6

18 19 20

21 22 23 24 25 26 27 28

1 2 3 4 5

11

10

12 13 14

16 17

15

29 30

6 7 8 9

AB(diag)-38

Airbag Warning Light Failure

AIRBAG SYSTEM (DIAGNOSTICS)

3

CHECK FUSE.
Remove fuse No. 5 from the fuse & relay box,
and perform visual inspection.

Is the fuse OK?

Go to step

4.

Replace the fuse. If
the fuse is blown
out again, 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 60 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 60 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-21,
Airbag Control
Module.>

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

Step

Check

Yes

No