Subaru Legacy 2002 Service Manual page 3196

DIAGNOSTICS FOR A/C SYSTEM FAILURE (RHD MODEL)
No.
1 CHECK SWITCH OPERATION.
Make sure that the mode selection on display
is changed when pushing the FRESH/
RECIRC switch.
2 CHECK FUSE.
1) Turn ignition switch to OFF.
2) Remove No. 17 fuse in joint box.
3) Check condition of fuse.
3 CHECK POWER SUPPLY VOLTAGE TO
BLOWER MODULE.
1) Remove glove box.
2) Turn ignition switch to ON.
3) Measure voltage between blower module
and chassis ground.
Connector & terminal
(i52) No. 1 (+) — Chassis ground (−):
4 CHECK SIGNAL VOLTAGE.
1) Change display to RECIRC by pushing
MODE switch.
2) Measure voltage between A/C control mod-
ule and chassis ground.
Connector & terminal
(i49) No. 12 (+) — Chassis ground (−):
5 CHECK SIGNAL VOLTAGE.
1) Change display to FRESH by pushing
MODE switch.
2) Measure voltage between A/C control mod-
ule and chassis ground.
Connector & terminal
(i49) No. 2 (+) — Chassis ground (−):
6 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
BLOWER MODULE.
1) Turn ignition switch to OFF.
2) Disconnect connector 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. 12 — (i52) No. 8
7 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
BLOWER MODULE.
Measure resistance of harness between A/C
control module and blower module.
Connector & terminal:
(i49) No. 2 — (i52) No. 5
8 CHECK POOR CONTACT.
Check poor contact in A/C control module.
Step
Does the mode selection
change?
Is the fuse blown-out?
Is the voltage more than 10
V?
Is the voltage less than 1
V?
Is the voltage less than 1
V?
Is the resistance less than
1 Ω?
Is the resistance less than
1 Ω?
Is there poor contact in A/C
control module?
AC-53
HVAC System (Auto A/C) (Diagnostics)
Check Yes
Go to step 8.
Replace fuse.
Go to step 4.
Go to step 5.
Go to step 6.
Go to step 7.
Go to step 8.
Repair poor con-
tact in A/C control
module.
No
Go to step 2.
Go to step 3.
Repair short cir-
cuit in harness for
power supply line.
Repair short cir-
cuit in harness for
power supply line.
Repair short cir-
cuit in harness for
power supply line.
Repair open cir-
cuit in harness
between A/C con-
trol module and
blower module.
Repair open cir-
cuit in harness
between A/C con-
trol module and
blower module.
Contact with your
Subaru distributor
service.