Subaru Legacy 2003 Service Manual page 3540

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) (RHD
Step
1 CHECK AMBIENT SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ambient sensor.
3) Measure resistance connector terminals of
ambient sensor.
Terminals
No. 1 — No. 2:
Is the measured value same as the speci-
fied value?
2 CHECK INPUT SIGNAL FOR AMBIENT SEN-
SOR.
1) Turn ignition ON.
2) Measure voltage between ambient sensor
harness connector terminals.
Connector & terminal
(F78) No. 2 (+) — No. 1 (-):
Is the measured value same as the speci-
fied value?
3 CHECK OUTPUT SIGNAL FROM A/C CON-
TROL MODULE.
1) Turn ignition switch to OFF.
2) Pull out A/C control panel.
3) Disconnect connector from ambient sensor.
4) Turn ignition switch to ON.
5) Measure voltage between connector termi-
nals of A/C control module.
Connector & terminal
(i48) No. 11 (+) — No. 10 (-):
Is the measured value same as the speci-
fied value?
4 CHECK HARNESS CONNECTOR BETWEEN
A/C CONTROL MODULE AND AMBIENT
SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from A/C control
module.
3) Measure resistance of harness between A/
C control module and ambient sensor.
Connector & terminal
(F78) No. 1 — (i48) No. 10:
Is the measured value less than the speci-
fied value?
5 CHECK HARNESS CONNECTOR BETWEEN
A/C CONTROL MODULE AND AMBIENT
SENSOR.
Measure resistance of harness between A/C
control module and ambient sensor.
Connector & terminal
(F78) No. 2 — (i48) No. 11:
Is the measured value less than the specified
value?
6 CHECK POOR CONTACT.
Check poor contact in A/C control module con-
nector.
Is there poor contact in connector?
MODEL)
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Value
Approx. 1.7 kΩ at 25°C (77°F) Go to step 2.
Approx. 4.5 V
Approx. 4.5 V
1 Ω
1 Ω
There is no poor contact.
AC-67
Yes
Replace ambient
sensor.
Go to step 6. Go to step 3.
Go to step 4. Go to step 6.
Go to step 5. Repair harness
between A/C con-
trol module and
ambient sensor.
Go to step 6. Repair harness
between A/C con-
trol module and
ambient sensor.
Replace A/C con- Repair connector.
trol module.
No