Subaru Legacy 2002 Service Manual page 3214

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) (RHD
No.
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
2 CHECK INPUT SIGNAL FOR AMBIENT
SENSOR.
1) Turn ignition ON.
2) Measure voltage between (F78) connector
terminals.
Connector & terminal:
(F78) No. 1 — No. 2
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
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
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
6 CHECK POOR CONTACT.
Check poor contact in A/C control module.
MODEL)
Step
Is the resistance approx.
2.2 kΩ at 25°C (77°F)?
Is the voltage approx. 4.5
V?
Is the voltage approx. 4.5
V?
Is the resistance less than
1 Ω?
Is the resistance less than
1 Ω?
Is there poor contact in A/C
control module?
AC-71
HVAC System (Auto A/C) (Diagnostics)
Check Yes
Go to step 2.
Go to step 6.
Go to step 4.
Go to step 5.
Go to step 6.
Repair poor con-
tact in A/C control
module.
No
Replace ambient
sensor.
Go to step 3.
Go to step 6.
Repair open cir-
cuit in harness
between A/C con-
trol module and
ambient sensor.
Repair open cir-
cuit in harness
between A/C con-
trol module and
ambient sensor.
Contact with your
Subaru distributor
service.