Subaru IMPREZA GD 2007 Series Manual page 3882

asieps_tobira_IM_US.book 17 ページ ２０１２年１月１７日 火曜日 午後３時４８分
Step
1 CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse No. 2 from the main fuse
box.
3) Check the condition of fuse.
2 CHECK POWER SUPPLY TO MAGNET
CLUTCH OF A/C COMPRESSOR.
1) Start the engine and turn the A/C switch to
ON.
2) Turn the temperature control dial at maxi-
mum cool position.
3) Measure the voltage between the magnet
clutch connector and chassis ground.
Connector & terminal
(F24) No. 1 (+) — Chassis ground (–):
3 CHECK SIGNAL VOLTAGE TO A/C RELAY.
1) Turn the ignition switch to ON.
2) Turn the A/C switch to ON.
3) Measure the signal voltage between A/C
relay and chassis ground.
Connector & terminal
(F129) No. 9 (+) — Chassis ground (–):
4 CHECK A/C RELAY.
Check the A/C relay. <Ref. to AC-36, INSPEC-
TION, Relay and Fuse.>
5 CHECK MAIN FAN MOTOR OPERATION.
1) Start the engine.
2) Turn the A/C switch to ON.
3) Check the operation of the main fan motor.
6 CHECK POWER SUPPLY TO MAIN FAN MO-
TOR.
CAUTION:
Be careful not to overheat the engine during
repair.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the main fan
motor.
3) Start the engine, and warm it up until engine
coolant temperature rise to 95°C (203°F)
higher.
4) Stop the engine and turn the ignition switch
to ON.
5) Measure the voltage between main fan
motor connector and chassis ground.
Connector & terminal
(F17) No. 1 (+) — Chassis ground (–):
(F17) No. 2 (+) — Chassis ground (–):
7 CHECK MAIN FAN MOTOR GROUND CIR-
CUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between main fan
motor connector and chassis ground.
Connector & terminal
(F17) No. 3 — Chassis ground:
(F17) No. 4 — Chassis ground:
8 CHECK POOR CONTACT.
Check poor contact of the main fan motor con-
nector.
Diagnostics for A/C System Malfunction
Is the fuse blown out?
Is the voltage 10 V or more?
Is the voltage 10 V or more?
Does the relay operate nor-
mally?
Does the radiator main fan
operate?
Is the voltage 10 V or more?
Is the resistance less than 1 Ω? Go to step 8.
Is there poor contact in the
main fan motor connector?
AC(diag)-17
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Check Yes
Replace the fuse.
Go to step 3.
Go to step 4.
Go to step 5.
Go to step 10.
Go to step 7.
Repair the poor
contact of main fan
motor connector.
No
Go to step 2.
Repair the open
circuit of A/C com-
pressor power sup-
ply line harness.
Repair the open
circuit in harness
of the A/C relay
signal circuit.
Replace the A/C
relay.
Go to step 6.
Repair the open
circuit of main fan
motor power sup-
ply circuit harness.
Repair the open
circuit of the har-
ness between
main fan motor
connector and
chassis ground.
Go to step 9.