Subaru 2009 IMPREZA, Service Manual

Page: 2743 / 3619

AC(diag)-14
Diagnostics for A/C System Malfunction
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Step Check Yes No
1 CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse No. 7, No. 22 and No. 31
from fuse & relay box.
3) Check the condition of fuse.
Is the fuse blown out? Replace the fuse. Go to step 2 .
2 CHECK A/C CONTROL MODULE POWER
CIRCUIT.
1) Remove the A/C control panel.
2) Disconnect the A/C control panel harness
connector.
3) Turn the ignition switch to ACC, and mea-
sure the voltage between A/C control panel har-
ness connector terminal and chassis ground.
Connector & terminal
(i88) No. 15 (+) — Chassis ground (–):
Is the voltage 10 V or more? Go to step 3 . Check for open or
short circuit in the
harness between
A/C control panel
and fuse.
3 CHECK A/C CONTROL MODULE POWER
CIRCUIT.
Measure the voltage between A/C control panel
harness connector terminal and chassis ground
after turning the ignition switch to ON.
Connector & terminal
(i88) No. 32 (+) — Chassis ground (–):
Is the voltage 10 V or more? Go to step 4 . Check for open or
short circuit in the
harness between
A/C control panel
and fuse.
4 CHECK A/C CONTROL PANEL GROUND
POWER CIRCUIT.
Measure the resistance of harness between
A/C control panel and chassis ground after turn-
ing the ignition switch to OFF.
Connector & terminal
(i88) No. 34 — Chassis ground:
Is the resistance less than 10
:
? Go to step 5 . Repair the harness
for ground line.
5 CHECK POOR CONTACT.
Check poor contact of auto A/C control module
connector.
Is there poor contact of connec-
tor? Repair the connec-
tor. Replace the auto
A/C control mod-
ule. <Ref. to AC-
33, REMOVAL,
Control Unit (Auto
A/C Model).>