Subaru Legacy 2005 Service Manual page 3508

HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Step
1 CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse No. 8 from main fuse box.
3) Check the condition of fuse.
2 CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse No. 22 and 31 from fuse &
relay box.
3) Check the condition of fuse.
3 CHECK A/C CONTROL PANEL POWER CIR-
CUIT.
1) Replace the A/C control panel.
2) Disconnect the A/C control panel harness
connector.
3) Measure the voltage between A/C control
panel harness connector terminal and chassis
ground after turning the ignition switch to ACC
position.
Connector & terminal
(i88) No. 2 (+) — Chassis ground (
4 CHECK A/C CONTROL PANEL POWER CIR-
CUIT.
Measure the voltage between A/C control
panel harness connector terminal and chassis
ground after turning the ignition switch to ON
position.
Connector & terminal
(i88) No. 1 (+) — Chassis ground (
5 CHECK A/C CONTROL PANEL GROUND
POWER CIRCUIT.
Measure the resistance in harness between A/
C control panel and chassis ground after turn-
ing the ignition switch to OFF position.
Connector & terminal
(i88) No. 5 — Chassis ground:
6 CHECK AUTO A/C CONTROL MODULE
POWER CIRCUIT.
Measure the voltage between auto A/C control
module connector terminal and chassis ground
after turning the ignition switch to OFF posi-
tion.
Connector & terminal
(B282) No. 1 (+) — Chassis ground (
7 CHECK AUTO A/C CONTROL MODULE
POWER CIRCUIT.
Measure the voltage between auto A/C control
module connector terminal and chassis ground
after turning the ignition switch to ACC posi-
tion.
Connector & terminal
(B282) No. 2 (+) — Chassis ground (
8 CHECK AUTO A/C CONTROL MODULE
POWER CIRCUIT.
Measure the voltage between auto A/C control
module connector terminal and chassis ground
after turning the ignition switch to ON position.
Connector & terminal
(B282) No. 9 (+) — Chassis ground (
Diagnostics for A/C System Malfunction
Is the fuse blown-out?
Is the fuse blown-out?
Is the voltage more than 10 V? Go to step 4.
−
):
Is the voltage more than 10 V? Go to step 5.
−
):
Is the resistance less than 10
Ω?
Is the voltage more than 10 V? Go to step 7.
−
):
Is the voltage more than 10 V? Go to step 8.
−
):
Is the voltage more than 10 V? Go to step 9.
−
):
AC(diag)-16
Check
Replace the fuse.
Replace the fuse.
Go to step 6.
Yes No
Go to step 2.
Go to step 3.
Check the harness
for open or short
circuit between A/
C control panel
and fuse.
Check the harness
for open or short
circuit between A/
C control panel
and fuse.
Repair the har-
ness for ground
line.
Check the harness
for open or short
circuit between
auto A/C control
module and fuse.
Check the harness
for open or short
circuit between
auto A/C control
module and fuse.
Check the harness
for open or short
circuit between
auto A/C control
module and fuse.