Subaru Forester 2004 - Page 90

AC-36
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
Diagnostic Procedure for Sensors
Step Check Yes No
1 CHECK IN-VEHICLE SENSOR.
1) Turn the ignition switch to OFF.
2) Remove the instrument panel lower cover.
3) Disconnect the connector from in-vehicle
sensor.
4) Measure the resistance between connector
terminals of in-vehicle sensor.
Terminals
No. 1 — No. 2:
Is the resistance approx. 2.7
kΩ at 20°C (68°F)?
Go to step 2. Replace the in-
vehicle sensor.
2 CHECK INPUT SIGNAL FOR IN-VEHICLE
SENSOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between in-vehicle
sensor harness connector terminal and chas-
sis ground.
Connector & terminal
LHD model:
(i55) No. 2 (+) — Chassis ground (
− ):
RHD model:
(B314) No. 2 (+) — Chassis ground (
− ):
Is the voltage approx. 5 V? Go to step 6. Go to step 3.
3 CHECK AUTO A/C CONTROL MODULE
OUTPUT SIGNAL.
1) Turn the ignition switch to OFF.
2) Remove the auto A/C control module.
3) Turn the ignition switch to ON.
4) Measure the voltage between connector
terminals of auto A/C control module.
Connector & terminal
(i49) No. 12 (+) — (i48) No. 16:
Is the voltage approx. 5 V? Go to step 4. Go to step 6.
4 CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND IN-VEHICLE SEN-
SOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from auto A/C
control module.
3) Measure the resistance in harness
between auto A/C control module and in-vehi-
cle sensor.
Connector & terminal
LHD model:
(i55) No. 2 — (i49) No. 12:
RHD model:
(B314) No. 2 — (i49) No. 12:
Is the resistance less than 1
Ω?
Go to step 5. Repair the har-
ness between auto
A/C control mod-
ule and in-vehicle
sensor.
5 CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND IN-VEHICLE SEN-
SOR.
Measure the resistance in harness between
auto A/C control module and in-vehicle sensor.
Connector & terminal
LHD model:
(i55) No. 1 — (i48) No. 16:
RHD model:
(B314) No. 1 — (i48) No. 16:
Is the resistance less than 1
Ω?
Go to step 6. Repair the har-
ness between auto
A/C control mod-
ule and in-vehicle
sensor.
6 CHECK POOR CONTACT.
Check poor contact in auto A/C control module
connector.
Is there poor contact in con-
nector?
Repair the con-
nector.
Replace the auto
A/C control mod-
ule.