Subaru Legacy 2004 Service Manual page 3441

Step
1 CHECK POWER SUPPLY FOR AIR MIX
DOOR ACTUATOR POSITION SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the air mix door actuator con-
nector.
3) Turn the ignition switch and AUTO switch to
ON.
4) Measure the voltage between auto A/C
control module connector terminals.
Connector & terminal
(B282) No. 8 (+) — (B282) No. 15 (
2 CHECK POWER SUPPLY FOR AIR MIX
DOOR ACTUATOR.
Measure the voltage between auto A/C control
module connector and chassis ground after
turning the temperature control dial to maxi-
mum COOL position.
Connector & terminal
(B283) No. 8 (+) — Chassis ground (
3 CHECK POWER SUPPLY FOR AIR MIX
DOOR ACTUATOR.
Measure the voltage between auto A/C control
module connector and chassis ground after
turning the temperature control dial to maxi-
mum HOT position.
Connector & terminal
(B283) No. 18 (+) — Chassis ground (
4 CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND AIR MIX DOOR
ACTUATOR.
1) Turn the A/C and ignition switch to OFF.
2) Disconnect the auto A/C control module
connector.
3) Measure the resistance between auto A/C
control module and air mix door actuator con-
nector.
Connector & terminal
(B235) No. 1 — (B282) No. 8:
(B235) No. 3 — (B282) No. 15:
(B235) No. 5 — (B282) No. 4:
(B235) No. 6 — (B283) No. 8:
(B235) No. 7 — (B283) No. 18:
5 CHECK AIR MIX DOOR ACTUATOR POSI-
TION SWITCH SIGNAL.
1) Connect the connector of auto A/C control
module and air mix door actuator.
2) Turn the ignition switch and AUTO switch to
ON.
3) Check the voltage between auto A/C con-
trol module connector terminals while chang-
ing the setting temperature between maximum
COOL and maximum HOT.
Connector & terminal
(B282) No. 4 (+) — (B282) No. 15 (
6 CHECK POOR CONTACT.
Check poor contact in auto A/C control module
and connector.
Diagnostic Procedure for Actuators
Is the voltage approx. 5 V?
$
):
Is the voltage 7 V (at normal
temperature)?
$
):
Is the voltage 7 V (at normal
temperature)?
$
):
Is the resistance less than 1
#?
Does the voltage change
between 1 (Max. HOT) — 4
(Max. COOL) V?
$
):
Is there poor contact in con-
nector?
AC(diag)-29
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 the con-
nector.
No
Replace the auto
A/C control mod-
ule.
Replace the auto
A/C control mod-
ule.
Replace the auto
A/C control mod-
ule.
Repair the har-
ness between auto
A/C control mod-
ule and air mix
door actuator.
Replace the air
mix door actuator.
Replace the auto
A/C control mod-
ule.