Subaru Legacy IV (2008 year). Service manual — part 1011

AB(diag)-32

Airbag Warning Light Illumination Pattern

AIRBAG SYSTEM (DIAGNOSTICS)

11.Airbag Warning Light

Illumination Pattern

A: INSPECTION

Turn the ignition switch to ON, and confirm that the
airbag warning light remains on for approx. 6 sec-
onds then turns off afterwards.

(1) Airbag warning light

(2) Approx. 6 sec.

(3) Ignition switch ON

AB-00135

(1)

(2)

(3)

OFF

ON

AB(diag)-33

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.
• Connection of (AB1) and (B31) is improper.
• Connection of (AB6, AB17, and AB18) to airbag control module is improper.

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)-34

Airbag Warning Light Failure

AIRBAG SYSTEM (DIAGNOSTICS)

Step

Check

Yes

No

1

READ 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 2.

2

CHECK POOR CONTACT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 20 sec-
onds or more.
2) Confirm that the connectors of airbag con-
trol module (AB6, AB17, and AB18) are
securely connected.

Is there poor contact in connec-
tors (AB6, AB17, and AB18)?

If the poor contact
of the connector is
not fixed, replace
the airbag main
harness along with
body harness or
replace the airbag
control module.
<Ref. to AB-20,
Airbag Control
Module.>

Go to step 3.

3

CHECK AIRBAG MAIN HARNESS.
1) Remove the instrument panel lower cover
and disconnect the connectors (AB7) and
(AB2).
2) Remove the instrument panel side cover on
the passenger’s side and disconnect the con-
nectors (AB10) and (AB9).
3) Disconnect the connectors (AB6, AB17,
AB18) from the airbag control module, and con-
nect the test harness AG connector (1AG).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
5) 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 4.

Go to step 5.

4

CHECK GROUND CIRCUIT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 20 sec-
onds or more.
2) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
3) Connect the connector (1AG) in the test har-
ness AG to the chassis harness connector
(AB6).
4) 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

:? Replace the airbag

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

Repair the chassis
ground circuit.

5

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

Model without MID

(2AG) No. 5 — (i10) No. 13:

Model with MID

(2AG) No. 5 — (i11) No. 14:

Is the resistance less than 10

:? Check the combi-

nation meter.

Go to step 6.

AB(diag)-35

Airbag Warning Light Failure

AIRBAG SYSTEM (DIAGNOSTICS)

6

CHECK POOR CONTACT OF CONNECTORS
(AB1) AND (B31).
1) Turn the ignition switch to OFF, disconnect
the battery ground terminal, and wait 20 sec-
onds or more.
2) Confirm that there is a firm contact between
connectors (AB1) and (B31).

Is there poor contact in connec-
tors (AB1) and (B31)?

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

Go to step 7.

7

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