Subaru Legacy III (2000-2003 year). Manual — part 902

AB-34

AIRBAG SYSTEM (DIAGNOSTICS)

DIAGNOSTIC CHART WITH DIAGNOSTIC TROUBLE CODE (DTC)

B: DTC 12

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

CAUTION:
• Before diagnosing the airbag system, be sure to turn the ignition switch OFF, disconnect the
ground cable from the battery, and wait more than 20 seconds before starting to work.
• Before replacing the airbag module, roll connector, control module, and sensor, reconnect each
part and confirm that the warning light operates properly.
• When inspecting the airbag main harness, disconnect the airbag module connector of the driver
and passenger seats for safety reasons.
WIRING DIAGRAM:

10

11

AB6

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

AIRBAG CONTROL MODULE

AB6

AB9

AB10

INFLATOR

(PASSENGER SIDE)

1

2

AB9

1 2

AB-00363

AB-35

AIRBAG SYSTEM (DIAGNOSTICS)

DIAGNOSTIC CHART WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK PASSENGER'S AIRBAG MODULE.
1) Turn the ignition switch OFF, disconnect

the battery ground cable, and wait more
than 20 seconds.

2) Pull out the two stopper pins and lower the

glove box.

3) Disconnect the connector (AB10) from

(AB9).

4) Connect the connector (1K) in test harness

K to connector (AB9).

5) Connect two airbag resistors to connectors

(3K) and (4K) in test harness K.

6) Connect the battery ground cable and turn

the ignition switch ON.
Does the airbag warning light operate prop-
erly?

Operates properly.

Replace the pas-
senger airbag
module. <Ref. to
AB-13, Passen-
ger's Airbag Mod-
ule.>

Go to step 2.

2

CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch OFF, disconnect

the battery ground cable, and wait more
than 20 seconds.

2) Disconnect two airbag resistors from the

connectors (3K) and (4K) in test harness K.

3) Remove lower cover and disconnect the

connector (AB3) from (AB8).

4) Disconnect the connector (AB6) from the

airbag control module, and connect the
connector (1I) in test harness I2. <Ref. to
AB-17, Airbag Control Module.>

5) Measure the resistance between connector

(2I) in test harness I2 and the connector
(3K) in test harness K.

Connector & terminal

(2I) No. 2 — (3K) No. 4:
(2I) No. 5 — (3K) No. 3:

Is the measured value less than the speci-
fied value?

10

Ω

Go to step 3.

Replace airbag
main harness.
<Ref. to AB-15,
Main Harness.>

3

CHECK AIRBAG MAIN HARNESS.
Measure the resistance of the connector (2I) in
test harness I2.

Connector & terminal

(2I) No. 2 — No. 5:
(2I) No. 2 — Chassis ground:
(2I) No. 5 — Chassis ground:

Does the measured value exceed the specified
value?

1 M

Ω

Replace

airbag

control module.
<Ref. to AB-17,
Airbag Control
Module.>

Replace airbag
main harness.
<Ref. to AB-15,
Main Harness.>

AB-36

AIRBAG SYSTEM (DIAGNOSTICS)

DIAGNOSTIC CHART WITH DIAGNOSTIC TROUBLE CODE (DTC)

C: DTC 15

DIAGNOSIS:
• Airbag main harness circuit (Driver) is shorted to the power supply.
• Airbag module harness (Driver) is shorted to the power supply.
• Roll connector is shorted to the power supply.
• Driver's airbag module is faulty.
• Airbag control module is faulty.

CAUTION:
• Before diagnosing the airbag system, be sure to turn the ignition switch OFF, disconnect the
ground cable from the battery, and wait more than 20 seconds before starting to work.
• Before replacing the airbag module, roll connector, control module, and sensor, reconnect each
part and confirm that the warning light operates properly.
• When inspecting the airbag main harness, disconnect the driver's airbag module and passenger's
airbag module connectors for safety reasons.
WIRING DIAGRAM:

AB-00292

13

14

AIRBAG CONTROL MODULE

AB6

AB8

1 2

STEERING
ROLL CONNECTOR

AB8

AB3

1

2

AB6

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

AB7

INFLATOR

(DRIVER SIDE)

1

2

AB7

1 2

AB-37

AIRBAG SYSTEM (DIAGNOSTICS)

DIAGNOSTIC CHART WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK DRIVER'S AIRBAG MODULE.
1) Turn the ignition switch OFF, disconnect

the battery ground cable, and wait more
than 20 seconds.

2) Remove the driver's airbag module. <Ref.

to AB-12, REMOVAL, Driver's Airbag Mod-
ule.>

3) Connect the connector (AB7) to connector

(1F) in test harness F.

4) Connect the airbag resistor to connector

(3F) in test harness F.

5) Connect the battery ground cable and turn

the ignition switch ON.
Does the airbag warning light operate prop-
erly?

Operates properly.

Replace the
driver's airbag
module. <Ref. to
AB-12,
REMOVAL,
Driver's Airbag
Module.>

Go to step 2.

2

CHECK ROLL CONNECTOR.
1) Turn the ignition switch OFF, disconnect

the battery ground cable, and wait more
than 20 seconds.

2) Disconnect the test harness from the con-

nector (AB7).

3) Remove the lower cover panel and discon-

nect the connector (AB3) from (AB8).

4) Connect the connector (1F) in test harness

F to connector (AB8).

5) Connect the airbag resistor to connector

(3F) in test harness F.

6) Connect the battery ground cable and turn

the ignition switch ON.
Does the airbag warning light operate prop-
erly?

Operates properly.

Replace the roll
connector. <Ref.
to AB-19,
REMOVAL, Roll
Connector.>

Go to step 3.

3

CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch OFF, disconnect

the battery ground cable, and wait more
than 20 seconds.

2) Disconnect the airbag resistor from the

connector (3F) in test harness F.

3) Pull out the two stopper pins and lower the

glove box, and disconnect connectors
(AB10) and (AB9).

4) Disconnect the connector (AB6) from the

airbag control module, and connect the
connector (1I) in test harness I2. <Ref. to
AB-17, REMOVAL, Airbag Control Mod-
ule.>

5) Connect the battery ground cable and turn

the ignition switch ON. (Engine OFF)

6) Measure the voltage between connector

(2I) in test harness I2 and the chassis
ground.

Connector & terminal

(2I) No. 4 (+) — Chassis ground (

−−−−

):

(2I) No. 1 (+) — Chassis ground (

−−−−

):

Is the measured value less than the speci-
fied value?

1 V

Replace the airbag
control module.
<Ref. to AB-17,
REMOVAL, Air-
bag Control Mod-
ule.>

Replace airbag
main harness.
<Ref. to AB-15,
REMOVAL, Main
Harness.>