SUBARU FORESTER 2004 Service Repair Manual

AB-59
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK AIRBAG CONTROL MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the connector (AB3) from the
airbag control module. Control Module.>
3) Connect the connector (1R) in test harness
R to connector (AB3).
4) Connect the battery ground cable and turn
the ignition switch to ON.
5) Measure the voltage between connector
(2R) in test harness R and chassis ground.
Connector & terminal
(2R) No. 1 (+) — Chassis ground (
−): Is the voltage more than 10 V? Replace the airbag
control module.
Airbag Control
Module.>Go to step 2.
2 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the airbag connector (AB1)
from the body harness (B31).
3) Connect the connector (2M) in test harness
M to connector (AB1).
4) Measure the resistance between connector
(5M) in test harness M and the connector (2R)
in test harness R.
Connector & terminal
(5M) No. 2 — (2R) No. 1: Is the resistance less than 10
Ω?Go to step 3.Replace the airbag
main harness with
body harness.
3 CHECK AIRBAG MAIN HARNESS.
Measure the following resistance with the
above-mentioned condition maintained.
Connector & terminal
(5M) No. 2 — Chassis ground:
(2R) No. 1 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 4.Replace the airbag
main harness with
body harness.
4 CHECK FUSE No. 11 (IN JOINT BOX).
1) Confirm that the ignition switch is turned
OFF.
2) Remove the fuse No. 11 (in fuse and relay
box) and perform visual inspection.Is the fuse No. 11 blown out? Replace the fuse
No. 11. If fuse No.
11 blows out
again, repair the
body harness. Repair the body
harness.

AB-60
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2. RHD MODEL
WIRING DIAGRAM:
AB-00745
AB3
AIRBAG CONTROL MODULEAB3
B31
AB1
AB1
6
6
BATTERY
NO.11
B31
12
34561
23 45 6
1234567891011121314151617
1819202122232425262728
IGNITION
SWITCH

AB-61
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK AIRBAG CONTROL MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the connector (AB3) from the
airbag control module. Control Module.>
3) Connect the connector (1R) in test harness
R to connector (AB3).
4) Connect the battery ground cable and turn
the ignition switch to ON.
5) Measure the voltage between connector
(2R) in test harness R and chassis ground.
Connector & terminal
(2R) No. 1 (+) — Chassis ground (
−): Is the voltage more than 10 V? Replace the airbag
control module.
Airbag Control
Module.>Go to step 2.
2 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the airbag connector (AB1)
from the body harness (B31).
3) Connect the connector (2M) in test harness
M to connector (AB1).
4) Measure the resistance between connector
(5M) in test harness M and the connector (2R)
in test harness R.
Connector & terminal
(5M) No. 9 — (2R) No. 1: Is the resistance less than 10
Ω?Go to step 3.Replace the airbag
main harness with
body harness.
3 CHECK AIRBAG MAIN HARNESS.
Measure the following resistance with the
above-mentioned condition maintained.
Connector & terminal
(5M) No. 9 — Chassis ground:
(2R) No. 1 — Chassis ground: Is the resistance more than 1
MΩ? Go to step 4.Replace the airbag
main harness with
body harness.
4 CHECK FUSE No. 11 (IN FUSE AND RELAY
BOX).
1) Confirm that the ignition switch is turned
OFF.
2) Remove the fuse No. 11 (in fuse and relay
box) and perform visual inspection.Fuse No. 11 is not blown out. Replace the fuse
No. 11. If fuse No.
11 blows out
again, repair the
body harness. Repair the body
harness.

AB-62
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
I: DTC 25
DIAGNOSIS:
 Airbag control module is faulty.
 Airbag main harness circuit is open.
 Fuse No. 6 (in joint box) is blown.
 Body harness circuit is open.
CAUTION:
 Before diagnosing the airbag system, be sure to turn the ignition switch to OFF, disconnect the
ground cable from battery, and wait more than 20 seconds before starting to work.
 After replacing the airbag module, seat belt pretensioner, roll connector, control module or sensor,
reconnect each part and confirm that the airbag 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.
1. LHD MODEL
WIRING DIAGRAM:
AB-00624
AB3
AIRBAG CONTROL MODULEAB3
B31
AB1
AB1
2
5
BATTERY
IG SW
NO.6
B31
12
34561
23 45 61234567891011121314151617
1819202122232425262728

AB-63
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK AIRBAG CONTROL MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the connector (AB3) from air-
bag control module. Control Module.>
3) Connect the connector (1R) in test harness
R to connector (AB3).
4) Connect the battery ground cable, and turn
the ignition switch to ON.
5) Measure the voltage between the connec-
tor (2R) in test harness R and the chassis
ground.
Connector & terminal
(2R) No. 6 (+) — Chassis ground (
−): Is the voltage more than 10 V? Replace the airbag
control module.
Airbag Control
Module.>Go to step 2.
2 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the airbag connector (AB1)
from the body harness (B31).
3) Connect the connector (2M) in test harness
M to the airbag connector (AB1).
4) Measure the resistance between the con-
nector (5M) in test harness M and the connec-
tor (2R) in test harness R.
Connector & terminal
(5M) No. 4 — (2R) No. 6: Is the resistance less than 10
Ω?Go to step 3.Replace the airbag
main harness with
body harness.
3 CHECK AIRBAG MAIN HARNESS.
Measure the following resistance with the
above-mentioned condition maintained.
Connector & terminal
(5M) No. 4 — Chassis ground:
(2R) No. 6 — Chassis ground: Is the resistance more than 1
MΩ?Go to step 4.Replace the airbag
main harness with
body harness.
4 CHECK FUSE NO. 6 (IN FUSE AND RELAY
BOX).
1) Confirm that the ignition switch is turned
OFF.
2) Remove the No. 6 fuse (in fuse and relay
box) and perform visual inspection.Is the fuse No. 6 blown out? Replace the fuse
No. 6. If fuse No. 6
is blown out again,
repair the body
harness. Repair the body
harness.

AB-64
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2. RHD MODEL
WIRING DIAGRAM:
AB-00746
AB3
AIRBAG CONTROL MODULEAB3
B31
AB1
AB1
5
5
BATTERY
NO.6
B31
12
34561
23 45 61234567891011121314151617
1819202122232425262728
IGNITION
SWITCH

AB-65
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK AIRBAG CONTROL MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the connector (AB3) from air-
bag control module. Control Module.>
3) Connect the connector (1R) in test harness
R to connector (AB3).
4) Connect the battery ground cable, and turn
the ignition switch to ON.
5) Measure the voltage between the connec-
tor (2R) in test harness R and the chassis
ground.
Connector & terminal
(2R) No. 6 (+) — Chassis ground (
−): Is the voltage more than 10 V? Replace the airbag
control module.
Airbag Control
Module.>Go to step 2.
2 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the airbag connector (AB1)
from the body harness (B31).
3) Connect the connector (2M) in test harness
M to the airbag connector (AB1).
4) Measure the resistance between the con-
nector (5M) in test harness M and the connec-
tor (2R) in test harness R.
Connector & terminal
(5M) No. 4 — (2R) No. 6: Is the resistance less than 10
Ω?Go to step 3.Replace the airbag
main harness with
body harness.
3 CHECK AIRBAG MAIN HARNESS.
Measure the following resistance with the
above-mentioned condition maintained.
Connector & terminal
(5M) No. 1 — Chassis ground:
(2R) No. 6 — Chassis ground: Is the resistance more than 1
MΩ? Go to step 4.Replace the airbag
main harness with
body harness.
4 CHECK FUSE NO. 6 (IN FUSE AND RELAY
BOX).
1) Confirm that the ignition switch is turned
OFF.
2) Remove the No. 6 fuse (in fuse and relay
box) and perform visual inspection.Is the fuse No. 6 blown out? Replace the fuse
No. 6. If fuse No. 6
is blown out again,
repair the body
harness. Repair the body
harness.

AB-66
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
J: DTC 31
DIAGNOSIS:
 Front sub-sensor harness circuit (RH) is shorted, open or shorted to power supply.
 Airbag main harness circuit is shorted, open or shorted to power supply.
 Front sub-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 more than 20 seconds before starting to work.
 After replacing the airbag module, seat belt pretensioner, roll connector, control module or sensor,
reconnect each part and confirm that the airbag 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-00747
AB3
AB13
AB14
AB15
AB3
LHD
RHD
LHD
RHD
LHD
FRONT SUB SENSOR RH
209
21
RHD
LHDRHD
AB13AB15
1212
AIRBAG CONTROL MODULE
1
2
1234567891011121314151617
1819202122232425262728

AB-67
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK FRONT SUB-SENSOR (RH) AND
AIRBAG HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the connector (AB3) from the
airbag control module, and connect the con-
nector (1R) in test harness R. Airbag Control Module.>
3) Measure the resistance of the connector
(3R) in test harness R.
Connector & terminal
(3R) No. 7 — (3R) No. 9: Is the resistance 750 Ω and 1
KΩ? Replace the airbag
control module.
Airbag Control
Module.>Go to step 2.
2 CHECK AIRBAG MAIN HARNESS AND
FRONT SUB-SENSOR HARNESS (RH).
1) Disconnect the connector (AB15) from the
front sub-sensor. Sensor.>
2) Connect the connector (IH) in test harness
H to connector (AB15).
3) Measure the resistance between connector
(3R) in test harness R and connector (3H) in
test harness H.
Connector & terminal
(3R) No. 7 — (3H) No. 5:
(3R) No. 9 — (3H) No. 6: Is the resistance less than 10
Ω?Go to step 3.LHD model:
Replace the airbag
main harness and
front sub-sensor
harness with body
harness.
RHD model:
Go to step 4.
3 CHECK AIRBAG MAIN HARNESS AND
FRONT SUB-SENSOR HARNESS (RH).
Measure the resistance between connector
(3R) in test harness R and the chassis ground.
Connector & terminal
(3R) No. 7 — Chassis ground:
(3R) No. 9 — Chassis ground: Is the resistance more than 1
MΩ?Go to step 8.LHD model:
Replace the airbag
main harness and
front sub-sensor
harness with body
harness.
RHD model:
Go to step 4.
4 CHECK AIRBAG MAIN HARNESS
1) Disconnect the connector (AB13) from
(AB14), and connect the connector (1L) in test
harness L to connector (AB13).
2) Measure the resistance between connector
(3R) in test harness R and connector (3L) in
test harness L.
Connector & terminal
(3R) No. 7 — (3L) No. 4:
(3R) No. 9 — (3L) No. 3: Is the resistance less than 10
Ω?Go to step 5.Replace the airbag
main harness with
body harness.
5 CHECK AIRBAG MAIN HARNESS
Measure the resistance between connector
(3R) in test harness R and the chassis ground.
Connector & terminal
(3R) No. 7 — Chassis ground:
(3R) No. 9 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 6.Replace the airbag
main harness with
body harness.
6 CHECK FRONT SUB-SENSOR HARNESS
(RH).
1) Connect the connector (2L) in test harness
F to the connector (AB14).
2) Measure the resistance between connector
(3H) in test harness H and connector (3L) in
the test harness L.
Connector & terminal
(3L) No. 5 — (3H) No. 5:
(3L) No. 6 — (3H) No. 6: Is the resistance less than 10
Ω?Go to step 7.Replace the front
sub-sensor har-
ness (RH) with
body harness.

AB-68
AIRBAG SYSTEM (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK FRONT SUB-SENSOR HARNESS
(RH).
Measure the resistance between connector
(3L) in test harness L and the chassis ground.
Connector & terminal
(3L) No. 5 — Chassis ground:
(3L) No. 6 — Chassis ground: Is the resistance more than 1
MΩ?Go to step 8.Replace the front
sub-sensor har-
ness (RH) with
body harness.
8 CHECK FRONT SUB-SENSOR (RH).
1) Connect the connector (2H) in test harness
H to front sub-sensor (RH).
2) Measure the resistance of the connector
(3H) in test harness H.
Connector & terminal
(3H) No. 3 — No. 4: Is the resistance 750 Ω and 1
KΩ?Go to step 9.Replace the front
sub-sensor (RH).
Front Sub Sen-
sor.>
9 CHECK FRONT SUB-SENSOR (RH).
Measure the resistance between connector
(3H) in test harness H and the chassis ground.
Connector & terminal
(3H) No. 3 — Chassis ground:
(3H) No. 4 — Chassis ground:Is the resistance more than 1
MΩ?Finish the diagno-
sis.Replace the front
sub-sensor (RH).
Front Sub Sen-
sor.> Step Check Yes No