Subaru Legacy 2002 Service Manual page 3194

DIAGNOSTICS FOR A/C SYSTEM FAILURE (RHD MODEL)
No.
1 CHECK OUTPUT SIGNAL FROM BLOWER
MODULE.
1) Turn ignition switch to OFF.
2) Remove glove box.
3) Start the engine.
4) Turn A/C switch to ON, and select
MANUAL mode.
5) Measure voltage between blower module
and chassis ground, when the blower fan
speed is in LO.
Connector & terminal
(i52) No. 3 (+) — Chassis ground (−):
2 CHECK OUTPUT SIGNAL FROM BLOWER
MODULE.
Measure voltage between blower module and
chassis ground, when the blower fan speed is
in HI.
Connector & terminal
(i52) No. 7 (+) — Chassis ground (−):
3 CHECK OUTPUT SIGNAL FROM BLOWER
MODULE.
Measure voltage between blower module and
chassis ground, when the blower fan speed is
in HI.
Connector & terminal
(i52) No. 12 (+) — Chassis ground (−):
4 CHECK OUTPUT SIGNAL FROM BLOWER
MODULE.
Measure voltage between blower module and
chassis ground, when the blower fan speed is
in HI.
Connector & terminal
(i52) No. 3 (+) — Chassis ground (−):
5 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
BLOWER MODULE.
1) Turn ignition switch to OFF.
2) Disconnect connectors from A/C control
module and blower module.
3) Measure resistance of harness between
A/C control module and blower module.
Connector & terminal:
(i49) No. 5 — (i52) No. 3
6 CHECK POOR CONTACT.
Check poor contact in A/C control module.
Step
Is the voltage more than 10
V?
Is the voltage more than 10
V?
Is the voltage approxi-
mately 0 V?
Is the voltage more than 5
V?
Is the resistance less than
1 Ω?
Is there poor contact in A/C
control module?
AC-51
HVAC System (Auto A/C) (Diagnostics)
Check Yes
Go to step 2.
Go to step 3.
Go to step 4.
Go to step 5.
Go to step 6.
Repair poor con-
tact in A/C control
module.
No
Replace blower
module.
Replace blower
module.
Replace blower
module.
Replace blower
module.
Repair open cir-
cuit in harness
between A/C con-
trol module and
blower module.
Contact with your
Subaru distributor
service.