Subaru Legacy 2003 Service Manual page 3528

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) (LHD
Step
1 CHECK EVAPORATOR SENSOR.
1) Turn ignition switch to OFF.
2) Remove glove box.
3) Disconnect connector from evaporator sen-
sor.
4) Measure resistance between connector ter-
minals of evaporator sensor.
Terminals
No. 1 — No. 3:
Is the measured value within the specified
range?
2 CHECK INPUT SIGNALS FOR EVAPORA-
TOR SENSOR.
1) Turn ignition switch to ON.
2) Measure voltage between evaporator sen-
sor harness connector terminal and chassis
ground.
Connector & terminal
(B88) No. 1 (+) — Chassis ground ( − − − − ):
Is the measured value the same as speci-
fied value?
3 CHECK OUTPUT SIGNALS FROM A/C CON-
TROL MODULE.
1) Turn ignition switch to OFF.
2) Pull out A/C control module.
3) Turn ignition switch to ON.
4) Measure voltage between A/C control mod-
ule connector terminals.
Connector & terminal
(i49) No. 7 (+) — No. 17 ( − − − − ):
Is the measured value the same as speci-
fied value?
4 CHECK HARNESS CONNECTOR BETWEEN
A/C CONTROL MODULE AND EVAPORA-
TOR 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 evaporator sensor.
Connector & terminal
(B88) No. 1 — (i49) No. 7:
Is the measured value less than the speci-
fied value?
5 CHECK HARNESS CONNECTOR BETWEEN
A/C CONTROL MODULE AND EVAPORA-
TOR SENSOR.
Measure resistance of harness between A/C
control module and evaporator sensor.
Connector & terminal
(B88) No. 3 — (i49) No. 17:
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. 1.8 to 2.0 kΩ: 20°C
(68°F)
Approx. 4.5 V
Approx. 4.5 V
1 Ω
1 Ω
There is no poor contact.
AC-55
Yes
Go to step 2. Replace evapora-
tor 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
evaporator sensor.
Go to step 6. Repair harness
between A/C con-
trol module and
evaporator sensor.
Replace A/C con- Repair connector.
trol module.
No