Subaru Legacy IV (2008 year). Manual — part 1029

AB(diag)-104

Diagnostic Chart with Trouble Code

AIRBAG SYSTEM (DIAGNOSTICS)

2

CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 20 sec-
onds or more.
2) Remove the instrument panel lower cover
and disconnect the connectors (AB7) and
(AB2).
3) Remove the instrument panel side cover on
the passenger’s side and disconnect the con-
nectors (AB9) and (AB10).
4) Disconnect the connectors (AB17, AB6,
AB18) from airbag control module.
5) Connect the connector (1AG) in the test har-
ness AG to the connectors (AB17, AB6, AB18).
6) Disconnect the front sub sensor (LH), and
then connect the connector (1H) in the test har-
ness H to connector (AB13).
7) Measure the resistance between connector
(4AG) in the test harness AG and connector
(3H) in the test harness H.

Connector & terminal

(4AG) No. 7 — (3H) No. 5:
(4AG) No. 9 — (3H) No. 6:

Is the resistance less than 10

:? Go to step 3.

Replace the airbag
main harness
along with body
harness.

3

CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS LH).
Measure the resistance between connector
(4AG) in the test harness AG and chassis
ground, and the resistance between connector
(4AG) in the test harness AG and connector
(3H) in test harness H.

Connector & terminal

(4AG) No. 7 — Chassis ground:
(4AG) No. 9 — Chassis ground:
(4AG) No. 7 — (4AG) No. 9:

Is the resistance 1 M

: or

more?

Go to step 4.

Replace the airbag
main harness
along with body
harness.

4

CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC.

Is the same DTC displayed?

Replace the front
sub sensor (LH).
<Ref. to AB-21,
REMOVAL, Front
Sub Sensor.>
Replace the airbag
control module if
not operating nor-
mally even after
replacing the sen-
sor. <Ref. to AB-
20, REMOVAL, Air-
bag Control Mod-
ule.>

Go to step 5.

5

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check DTC using
“List of Diagnostic
Trouble Code”.
<Ref. to AB(diag)-
38, LIST, List of
Diagnostic Trouble
Code (DTC).>

Finish the diagno-
sis.

Step

Check

Yes

No

AB(diag)-105

Diagnostic Chart with Trouble Code

AIRBAG SYSTEM (DIAGNOSTICS)

AR:DTC E9 SIDE SENSOR BUS RH COMMUNICATION ERROR

NOTE:
Refer to DTC EC for details on DTC E9. <Ref. to AB(diag)-106, DTC EC SIDE SENSOR BUS RH COMMU-
NICATION ERROR, Diagnostic Chart with Trouble Code.>

AS:DTC EA SIDE SENSOR BUS RH COMMUNICATION ERROR

NOTE:
Refer to DTC EC for details on DTC EA. <Ref. to AB(diag)-106, DTC EC SIDE SENSOR BUS RH COMMU-
NICATION ERROR, Diagnostic Chart with Trouble Code.>

AT:DTC EB SIDE SENSOR BUS RH COMMUNICATION ERROR

NOTE:
Refer to DTC EC for details on DTC EB. <Ref. to AB(diag)-106, DTC EC SIDE SENSOR BUS RH COMMU-
NICATION ERROR, Diagnostic Chart with Trouble Code.>

AB(diag)-106

Diagnostic Chart with Trouble Code

AIRBAG SYSTEM (DIAGNOSTICS)

AU:DTC EC SIDE SENSOR BUS RH COMMUNICATION ERROR

DTC DETECTING CONDITION:
• Open or short circuit in harness of side sensor bus (RH).
• Side airbag sensor (RH) and curtain airbag sensor (RH) 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 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 and seat belt
pretensioners of the driver’s and passenger’s seats for safety reasons.
• 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:

Step

Check

Yes

No

1

CHECK POOR CONTACT IN CONNECTORS.
Check for poor contact of the connectors
(AB18, AB28, AB34) between the airbag control
module and the curtain airbag sensor (RH).

Is there poor contact?

Replace the airbag
rear harness along
with body harness.

Go to step 2.

AB18

AB24

AB25

1

2

17

18

AB28

8

7

3

4

1

2

AB18

AB28

AB-02105

3

4

AB34

AB34

18 19 20 21 22 23 24

1 2 3 4

11

10

12 13 14

16

17

15

1 2 3 4

1 2

AB24

AIRBAG CONTROL MODULE

CURTAIN AIRBAG

SENSOR RH

(C PILLAR)

SIDE AIRBAG

SENSOR RH

(B PILLAR)

SIDE AIRBAG

MODULE RH

8

7

6

5

9

AB(diag)-107

Diagnostic Chart with Trouble Code

AIRBAG SYSTEM (DIAGNOSTICS)

2

CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 20 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner (RH).
3) Disconnect the connector (AB33) from cur-
tain airbag module (RH).
4) Disconnect connectors (AB25) and (AB24)
from side airbag module (RH).
5) Disconnect the connectors (AB17, AB6,
AB18) from airbag control module.
6) Connect the connector (1AG) in the test har-
ness AG to the connectors (AB17, AB6, AB18).
7) Disconnect the connector (AB28) from side
airbag sensor (RH), and connect the connector
(2V) in test harness V to connector (AB28).
8) Measure the resistance between connector
(5AG) in the test harness AG and connector
(3V) in the test harness V.

Connector & terminal

(5AG) No. 16 — (3V) No. 2:
(5AG) No. 14 — (3V) No. 1:

Is the resistance less than 10

:? Go to step 3.

Replace the airbag
rear harness along
with body harness.

3

CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR RH).
Measure the resistance between connector
(5AG) in the test harness AG and chassis
ground, and the resistance between connector
(5AG) in the test harness AG and connector
(3V) in test harness V.

Connector & terminal

(5AG) No. 16 — Chassis ground:
(5AG) No. 14 — Chassis ground:
(5AG) No. 14 — (5AG) No. 16:

Is the resistance 1 M

: or

more?

Go to step 4.

Replace the airbag
rear harness along
with body harness.

4

CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR AND CUR-
TAIN AIRBAG SENSOR RH).
1) Disconnect the connector (2V) in the test
harness V from the connector (AB28) of side
airbag sensor (RH).
2) Connect the connector (AB28) of side air-
bag sensor (RH) and the connector (1AI) in the
test harness AI.
3) Connect the connector (2AI) in the test har-
ness AI and the connector (1V) in the test har-
ness V.
4) Disconnect the connector (AB34) from cur-
tain airbag sensor (RH), and connect the con-
nector (2V) in test harness V to connector
(AB34).
5) Measure the resistance between connector
(3V) terminals in the test harness V.

Connector & terminal

(3V) No. 2 — (3V) No. 6:
(3V) No. 1 — (3V) No. 7:

Is the resistance less than 10
:?

Go to step 5.

Replace the airbag
rear harness along
with body harness.

Step

Check

Yes

No