Subaru Forester 2004 - Page 79

AC-25
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Procedure for Actuators
6 CHECK AUTO A/C CONTROL MODULE SIG-
NAL VOLTAGE.
1) Turn the ignition switch to ON.
2) Turn the mode control dial and measure
voltage between auto A/C control module har-
ness connector and chassis ground for each
mode.
Connector & terminal
(i48) No. 4 (+) — Chassis ground (
− ):
Is the voltage 5 V when HEAT,
D/H, DEF position and 0 V
when VENT, BI-LEVEL posi-
tion?
Go to step 9. Go to step 7.
7 CHECK AUTO A/C CONTROL MODULE SIG-
NAL POWER SUPPLY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mode door
actuator.
3) Turn the ignition switch to ON.
4) Measure the voltage between mode door
actuator harness connector and chassis
ground.
Connector & terminal
(B77) No. 5 (+) — Chassis ground (
− ):
Is the voltage 5 V? Go to step 9. Go to step 8.
8 CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND MODE DOOR AC-
TUATOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from auto A/C
control module and mode door actuator.
3) Measure the resistance of harness
between auto A/C control module and mode
door actuator.
Connector & terminal
(i48) No. 4 (+) — (B77) No. 5 (
− ):
Is the resistance less than 1
Ω?
Replace the auto
A/C control mod-
ule.
Repair the har-
ness between auto
A/C control mod-
ule and mode door
actuator.
9 CHECK AUTO A/C CONTROL MODULE SIG-
NAL VOLTAGE.
1) Turn ignition switch to ON.
2) Turn the mode control dial and measure
voltage between auto A/C control module har-
ness connector and chassis ground for each
mode.
Connector & terminal
(i48) No. 12 (+) — Chassis ground (
− ):
Is the voltage 5 V when VENT,
D/H position and 0 V when BI-
LEVEL, HEAT, DEF position?
Go to step 12. Go to step 10.
10 CHECK AUTO A/C CONTROL MODULE SIG-
NAL POWER SUPPLY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mode door
actuator.
3) Turn the ignition switch to ON.
4) Measure the voltage between mode door
actuator harness connector and chassis
ground.
Connector & terminal
(B77) No. 6, 9 (+) — Chassis ground (
− ):
Is the voltage 5 V? Go to step 12. Go to step 11.
Step Check Yes No