Subaru Legacy 2004 Service Manual page 3447

Step
1 CHECK EVAPORATOR SENSOR
1) Turn the ignition switch to OFF.
2) Remove the glove box.
3) Disconnect the connector from evaporator
sensor.
4) Measure the resistance between connector
terminals of evaporator sensor.
Terminals
No. 1 — No. 2:
2 CHECK INPUT SIGNAL FOR EVAPORATOR
SENSOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between connector
(B88) terminal and chassis ground.
Connector & terminal
(B88) No. 1 (+) — No. 2 (
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
(B282) No. 13 (+) —No. 15 (
4 CHECK HARNESS CONNECTOR BETWEEN
AUTO A/C CONTROL MODULE AND EVAP-
ORATOR SENSOR.
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 evapo-
rator sensor.
Connector & terminal
(B88) No. 2 — (B282) No. 15:
5 CHECK HARNESS CONNECTOR BETWEEN
AUTO A/C CONTROL MODULE AND EVAP-
ORATOR SENSOR.
Measure the resistance in harness between
auto A/C control module and evaporator sen-
sor.
Connector & terminal
(B88) No. 1 — (B282) No. 13:
6 CHECK POOR CONTACT.
Check poor contact in auto A/C control module
connector.
Diagnostic Procedure for Sensors
Is the resistance approx. 3.3
k# at 20!C (68!F)?
Is the voltage approx. 5 V?
$
):
Is the voltage approx. 5 V?
$
):
Is the resistance less than 1
#?
Is the resistance less than 1
#?
Is there poor contact in con-
nector?
AC(diag)-35
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 the con-
nector.
No
Replace the evap-
orator sensor.
Go to step 3.
Go to step 6.
Repair the open
circuit in harness
between auto A/C
control module
and evaporator
sensor.
Repair the open
circuit in harness
between auto A/C
control module
and evaporator
sensor.
Replace the auto
A/C control mod-
ule.