Subaru Legacy 2004 Service Manual page 3425

3. A/C CONTROL SYSTEM SELF-DIAGNOSIS
Step
1 SET SELF-DIAGNOSIS MODE BY OPERAT-
ING A/C CONTROL PANEL.
1) Turn the ignition switch to OFF.
2) Start the engine with the auto switch and
FRESH/RECIRC switch pressed.
NOTE:
Self-diagnosis can also be performed with igni-
tion switch ON, but start the engine because
telling the magnet clutch operation is difficult.
3) All the indicator blinks four times.
2 CHECK EACH SENSOR AND POTENTIO-
METER
1) After the indicators are completed to blink,
automatically change to the inspection mode of
sensor and potentiometer.
NOTE:
Display items can be changed each time the A/
C switch is pressed. (Step Operation)
2) When malfunction occurs in each sensor
and potentiometer, codes are displayed on the
screen. When no malfunction occurs in each
sensor and potentiometer, code "20" is dis-
played on the screen.
3) Identify the defective sensor according to
the sensor check table. <Ref. to AC(diag)-14,
SENSOR CHECK TABLE, OPERATION,
Diagnostic Chart for Self-Diagnosis.>
3 CHECK EACH ACTUATOR, BLOWER FAN
AND MAGNET CLUTCH.
1) After completing each sensor and potenti-
ometer inspection, change to the inspection
mode of actuator, blower fan and magnet
clutch by pressing the defroster switch.
2) Each mode will change and operate auto-
matically every four seconds.
NOTE:
Operation mode items can be changed each
time the A/C switch is pressed. (Step Opera-
tion)
3) Check the operation of actuator, blower fan
and magnet clutch in each mode according to
the operating mode table. <Ref. to AC(diag)-
14, OPERATING MODE TABLE, OPERA-
TION, Diagnostic Chart for Self-Diagnosis.>
Diagnostic Chart for Self-Diagnosis
Does the self-diagnosis mode
operate?
Are other codes except "20"
displayed?
Do the actuator, blower fan and
magnet clutch operate along
the operating mode table?
AC(diag)-13
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Check Yes
Go to step 2.
Repair the defec-
tive sensor. <Ref.
to AC(diag)-30,
Diagnostic Proce-
dure for Sensors.>
A/C control system
is normal. Press
the OFF switch
and complete the
self-diagnosis
mode.
No
<Ref. to AC(diag)-
15, A/C OR SELF-
DIAGNOSIS SYS-
TEMS DO NOT
OPERATE, Diag-
nostics for A/C
System Malfunc-
tion.>
Go to step 3.
Repair the mal-
function part in
accordance with
each diagnostic
chart. <Ref. to
AC(diag)-15, Diag-
nostics for A/C
System Malfunc-
tion.> or <Ref. to
AC(diag)-24, Diag-
nostic Procedure
for Actuators.>