2004 SUBARU FORESTER fuse

AC-18
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostics for A/C System Malfunction
Step Check Yes No
1 CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the main fan fuse and sub fan fuse
in main fuse box.
3) Check the condition of fuse.Is the fuse blown out? Replace the fuse. Go to step 2.
2 CHECK THE POWER SUPPLY TO PRES-
SURE SWITCH.
1) Disconnect the connector from pressure
switch.
2) Turn the ignition switch to ON.
3) Measure the voltage between harness con-
nector and chassis ground.
Connector & terminal
(F79) No. 1 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 3.Repair the har-
ness for pressure
switch power sup-
ply circuit.
3 CHECK THE HARNESS BETWEEN PRES-
SURE SWITCH AND A/C RELAY HARNESS.
1) Turn the ignition switch to OFF.
2) Remove the A/C relay in the main fuse box.
3) Measure the resistance between A/C relay
and pressure switch connector.
Connector & terminal
(F27) No. 17 — (F79) No. 2:Is the resistance less than 1
Ω?Go to step 4.Repair the har-
ness between A/C
relay and pres-
sure switch.
4 CHECK THE PRESSURE SWITCH.
Measure the resistance between pressure
switch terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance less than 1
Ω?Go to step 5.Replace the pres-
sure switch.
5 CHECK THE A/C CUT SIGNAL CIRCUIT.
1) Disconnect the connector from auto A/C
control module.
2) Measure the resistance between auto A/C
control module and pressure switch connector.
Connector & terminal
(i48) No. 10 — (F79) No. 2:Is the resistance less than 1
Ω?Go to step 6.Repair the har-
ness between auto
A/C control mod-
ule and pressure
switch.
6 CHECK THE A/C ON SIGNAL CIRCUIT.
1) Disconnect the connector from ECM.
2) Measure the resistance between ECM and
auto A/C control module connector.
Connector & terminal
Turbo model
(B137) No. 17 — (i49) No. 17:
Non-turbo model
(B136) No. 11 — (i49) No. 17:Is the resistance less than 1
Ω?Go to step 7.Repair the har-
ness between auto
A/C control mod-
ule and ECM.
7 CHECK A/C RELAY.
1) Remove the A/C relay in main fuse box.
2) Check the A/C relay. INSPECTION, Relay and Fuse.>Is the operation of the relay
OK?Go to step 8.Replace the A/C
relay.
8 CHECK POWER SUPPLY TO MAGNET
CLUTCH OF A/C COMPRESSOR.
1) Turn the ignition switch to OFF, and then
connect the A/C relay connector and all
removed connectors.
2) Start the engine, and turn A/C switch to
ON.
3) Set the temperature control dial to maxi-
mum cold position.
4) Measure the voltage between magnet
clutch harness connector and chassis ground.
Connector & terminal
(F24) No. 1 (+) — Chassis ground (
−):Is the voltage more than 10.5 V
(at normal temperature)?Go to step 9.Repair the har-
ness for power
supply line of A/C
compressor.

AC-22
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Procedure for Actuators
Step Check Yes No
1 CHECK POWER SUPPLY FOR INTAKE
DOOR ACTUATOR.
1) Turn the ignition switch to OFF.
2) Disconnect the intake door actuator con-
nector.
3) Turn the ignition switch to ON.
4) Measure the voltage between intake door
actuator connector and chassis ground.
Connector & terminal
(B91) No. 4 (+) — Chassis ground (
−):Is the voltage 7 V (at normal
temperature)?Go to step 2.Check open or
short circuit in har-
ness between
intake door actua-
tor and fuse.
2 CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND INTAKE DOOR
ACTUATOR.
1) Turn the ignition switch to OFF.
2) Disconnect the auto A/C control module
connector.
3) Measure the resistance between intake
door actuator connector and auto A/C control
module connector.
Connector & terminal
LHD model:
(i49) No. 18 — (B91) No. 2:
(i49) No. 19 — (B91) No. 3:
(i49) No. 20 — (B91) No. 1:
RHD model:
(i49) No. 18 — (B91) No. 1:
(i49) No. 19 — (B91) No. 3:
(i49) No. 20 — (B91) No. 2:Is the resistance less than 1
Ω?Go to step 3.Repair the har-
ness between auto
A/C control mod-
ule and intake
door actuator.
3 CHECK OPERATION OF INTAKE DOOR AC-
TUATOR.
1) Connect the intake door actuator connec-
tor.
2) Ground the auto A/C control module con-
nector with a suitable wire.
3) Turn the ignition switch to ON, and check
the operation of intake door actuator.
Connector & terminal
(i49) No. 20 — Chassis ground:Does the actuator move to
FRESH side?Go to step 4.Replace the intake
door actuator.
4 CHECK OPERATION OF INTAKE DOOR AC-
TUATOR.
1) Turn the ignition switch to OFF.
2) Ground the auto A/C control module con-
nector with a suitable wire.
3) Turn the ignition switch to ON, and check
the operation of intake door actuator.
Connector & terminal:
(i49) No. 18 — Chassis ground:Does the actuator move to
RECIRC side?Replace the auto
A/C control mod-
ule.Replace the intake
door actuator.

AC-41
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
General Diagnostic Table
9. General Diagnostic Table
A: INSPECTION
Symptom Problem parts
A/C system fails to operate.Fuse
 Connector (Poor contact)
Ground
 Auto A/C control module
 Blower fan motor
 Blower fan relay
 A/C Relay
 Compressor (Magnet clutch)
 Evaporator sensor
Fuse is blown out.Fuse
 Connector (Poor contact)
Illumination cannot dim.Fuse
 Connector (Poor contact)
 Auto A/C control module
Blower fan does not rotate or fan speed cannot be controlled.Fuse
 Connector (Poor contact)
Ground
 Auto A/C control module
 Blower fan motor
 Blower fan relay
Unable to switch suction vents. Connector (Poor contact)
 Auto A/C control module
 Intake door actuator
Unable to switch blow vents. Connector (Poor contact)
 Auto A/C control module
 Mode door actuator
Compartment temperature does not increase. (No hot air is dis-
charged.) Connector (Poor contact)
 Auto A/C control module
 Air mix door actuator
 In-vehicle sensor, ambient sensor, evaporator sensor and
sunload sensor
 In-vehicle sensor aspirator hose
Compartment temperature does not decrease. (No cool air is
discharged.) Connector (Poor contact)
 Auto A/C control module
 Air mix door actuator
 A/C Relay
 Compressor (Magnet clutch)
 Radiator fan motor
 Radiator fan relay
 In-vehicle sensor, ambient sensor, evaporator sensor and
sunload sensor
 In-vehicle sensor aspirator hose
Compartment temperature is higher or lower than setting tem-
perature. Auto A/C control module
 Air mix door actuator
 In-vehicle sensor, ambient sensor, evaporator sensor and
sunload sensor
 In-vehicle sensor aspirator hose
Compartment temperature does not quickly respond to setting
temperature. Air mix door actuator
 In-vehicle sensor, ambient sensor, evaporator sensor and
sunload sensor
 In-vehicle sensor aspirator hose
Radiator fan does not rotate during A/C operation. Radiator fan motor
 Radiator fan relay

AB-21
AIRBAG SYSTEM (DIAGNOSTIC)
Airbag Control Module I/O Signal
5. Airbag Control Module I/O Signal
A: WIRING DIAGRAM
1. LHD MODEL
B31(BLACK)(GREEN)
(GREEN) (YELLOW)
(YELLOW)B82
WI-03204
7
6
2
3
8
GWGRGY
GY
R
GRGB
GRL
W
GYRGRLW
19
BB28
1
R
2354
653192
AIRBAG
CIRCUIT AIRBAG
WARNING LED
IG
IGNITION RELAY
(IG) FB-33
F/B FUSE No. 14
(IG)FB-20
F/B FUSE No. 11
(IG)FB-21
F/B FUSE No. 6
(IG)
L
GR
GW
W
B
GRGR5GR
GB
B9
C8
BB10
1
2
L
W
REF. TO GND(L)-04
CHECK
CONNECTOR
DIAGNOSIS
CONNECTOR
DIAGNOSIS
TERMINAL
B31
AB1
AIRBAG CONTROL MODULE
AB3
B81
B82
B79B38i3
B37i2
TO POWER SUPPLY ROUTING
(GRAY)
B79
1234567891011121314
B
B
12
3456
B37
AB3
COMBINATION
METER B: C:
i11i10
i11
i10 B: C:
A/B(L)-01
A/B(L)-01
12345678910
123456789101112131415161718192021222324252627282930
34 128910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
1234567891011121314151617
1819202122232425262728
1
34562
B38
219
32
1234 5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25
REF. TO GND(L)-02
BB

AB-24
AIRBAG SYSTEM (DIAGNOSTIC)
Airbag Control Module I/O Signal
2. RHD MODEL
A/B(R)-01A/B(R)-01
WI-03206
7
6
2
3
8
GWGY
GY
R
GRGR
RGRL
W
YWLgRBR
10
BB20
65143
6
B
BW
2
2753192
IG
IGNITION RELAY
(IG)FB-36
F/B FUSE No. 14
(IG)FB-20
F/B FUSE No. 11
(IG)FB-21
F/B FUSE No. 6
(IG)
L
GR
GW
W
B
GYGY16GY
GR
B
B9
C8
B10
1
2
L
W
BL
BL
REF. TO GND(R)-04
REF. TO E/G(RNA)-05REF. TO E/G(RTB20)-05REF. TO E/G(RTB25)-05
CHECK
CONNECTOR
DIAGNOSIS
CONNECTOR
DIAGNOSIS
TERMINAL
B31
AB1
(GRAY)
B79
AIRBAG CONTROL MODULE
AB3
B81
B82
B79
B38i3
TO POWER SUPPLY ROUTING
1234567891011121314
GY
(BLACK)B82
B
REF. TO GND(R)-05
B
i3
B31(GREEN) i11 C:
B:
(GREEN)
i10
AIRBAG
CIRCUIT AIRBAG WARNING
LED LIGHT
COMBINATION
METER B: C:
i11i10
12
34561
3456212345678910
123456789101112131415161718192021222324252627282930
(YELLOW)
AB3
1234567891011121314151617
1819202122232425262728
(YELLOW)
219
32
1234
5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25

AB-39
AIRBAG SYSTEM (DIAGNOSTIC)
Airbag Warning Light Failure
B: AIRBAG WARNING LIGHT REMAINS OFF.
DIAGNOSIS:
 Fuse No. 14 (in fuse box) is blown.
 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 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 airbag module connector of the driver
and passenger seats for safety reasons.
1. LHD MODEL
WIRING DIAGRAM:
AB-00739
12
34561
2345678910123456789101112131415161718192021222324252627282930
B31 i11AB3
i10
B:
C: i10
i11
AIRBAG
WARNING
LIGHTCOMBINATION
METERB9
B8
B10
NO.14
i3B38 28
i2B37 19
5
AIRBAG CONTROL MODULEAB3
B31
AB1
3
3
AIRBAG
CIRCUIT
E
BATTERY
1234567891011121314151617
1819202122232425262728
IGNITION
SWITCH
B: C:

AB-40
AIRBAG SYSTEM (DIAGNOSTIC)
Airbag Warning Light Failure
Step Check Yes No
1 CHECK COMBINATION METER.
Turn the ignition switch to ON, and confirm that
warning lights equipped in the combination
meter are turned on.Do the warning lights not for
airbag turn on?Go to step 2.Repair the combi-
nation meter
power supply.
Combination
Meter System.>
2 CHECK FUSE NO. 14 (IN FUSE&RELAY
BOX).
Remove the fuse No. 14 and perform visual
inspection.Is the fuse No. 14 (in fuse &
relay box) blown out? Replace the fuse
No. 14. If fuse No.
14 blows again, go
to step 3. Go to step 3.
3 CHECK AIRBAG WARNING LIGHT CIRCUIT
(IN COMBINATION METER).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the connector (AB1) from
(B31).
3) Connect the battery ground cable and turn
the ignition switch to ON.Is the airbag warning light
turned on?Go to step 4.Replace the airbag
warning light bulb
or combination
meter printed cir-
cuit. 10, Combination
Meter Assembly.>
4 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Connect the connector (AB1) to (B31).
3) Disconnect the connector (AB3) from the
airbag control module. Control Module.>
4) Connect the battery ground cable and turn
the ignition switch to ON.Is the airbag warning light
turned on?Replace the airbag
control module.
Airbag Control
Module.>Replace the airbag
main harness with
body harness.

AB-42
AIRBAG SYSTEM (DIAGNOSTIC)
Airbag Warning Light Failure
Step Check Yes No
1 CHECK COMBINATION METER.
Turn the ignition switch to ON, and confirm that
warning lights equipped in the combination
meter are turned on.Do the warning lights not for
airbag turn on?Go to step 2.Repair the combi-
nation meter
power supply.
Combination
Meter System.>
2 CHECK FUSE NO. 14 (IN FUSE&RELAY
BOX).
Remove the fuse No. 14 and perform visual
inspection.Is the fuse No. 14 (in fuse &
relay box) blown out?Replace the fuse
No. 14. If fuse No.
14 blows again, go
to step 3. Go to step 3.
3 CHECK AIRBAG WARNING LIGHT CIRCUIT
(IN COMBINATION METER).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Disconnect the connector (AB1) from
(B31).
3) Connect the battery ground cable and turn
the ignition switch to ON.Is the airbag warning light
turned on?Go to step 4.Replace the airbag
warning light bulb
or combination
meter printed cir-
cuit. 10, Combination
Meter Assembly.>
4 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait more than
20 seconds.
2) Connect the connector (AB1) to (B31).
3) Disconnect the connector (AB3) from the
airbag control module. Control Module.>
4) Connect the battery ground cable and turn
the ignition switch to ON.Is the airbag warning light
turned on?Replace the airbag
control module.
Airbag Control
Module.>Replace the airbag
main harness with
body harness.