Subaru Legacy 2002 Service Manual page 3226

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) (RHD
No.
1 CHECK VENTILATION MOTOR.
1) Turn ignition switch to OFF.
2) Remove ventilation motor unit.
3) Make sure that ventilation motor is oper-
ated when connecting battery to air mix
motor.
Terminals:
Battery positive terminal — (E) No. 6
Battery negative terminal — (E) No. 7
2 CHECK POTENTIOMETER.
Measure resistance for the power supply line
of the potentiometer.
Terminals:
(E) No. 1 — No. 3
3 CHECK POTENTIOMETER.
Measure resistance for the signal line of the
potentiometer, when the lever is in the MAX
VENT position.
Terminals:
(E) No. 1 — No. 5
4 CHECK POTENTIOMETER.
Measure resistance for the signal line of the
potentiometer, when the lever is in the MAX
DEF position.
Terminals:
(E) No. 1 — No. 5
5 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
VENTILATION MOTOR UNIT.
1) Disconnect connector from A/C control
module.
2) Measure resistance of harness between
A/C control module and ventilation motor unit.
Connector & terminal:
(i48) No. 14 — (E) No. 5
6 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
VENTILATION MOTOR UNIT.
Measure resistance of harness between A/C
control module and ventilation motor unit.
Connector & terminal:
(i48) No. 5 — (E ) No. 3
7 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
VENTILATION MOTOR UNIT.
Measure resistance of harness between A/C
control module and ventilation motor unit.
Connector & terminal:
(i48) No. 10 — (E) No. 1
8 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
VENTILATION MOTOR UNIT.
Measure resistance of harness between A/C
control module and ventilation motor unit.
Connector & terminal:
(i48) No. 8 — (E) No. 7
MODEL)
Step
Does the ventilation motor
operate?
Is the resistance approx.
6.0 kΩ?
Is the resistance approx.
1.2 kΩ?
Is the resistance approx.
4.5 kΩ?
Is the resistance less than
1 Ω?
Is the resistance less than
1 Ω?
Is the resistance less than
1 Ω?
Is the resistance less than
1 Ω?
AC-83
HVAC System (Auto A/C) (Diagnostics)
Check Yes
Go to step 2.
Go to step 3.
Go to step 4.
Go to step 5.
Go to step 6.
Go to step 7.
Go to step 8.
Go to step 9.
No
Replace ventila-
tion motor unit.
Replace air mix
motor unit.
Replace ventila-
tion motor unit.
Replace ventila-
tion motor unit.
Repair short cir-
cuit in harness
between A/C con-
trol module and
ventilation motor
unit.
Repair short cir-
cuit in harness
between A/C con-
trol module and
ventilation motor
unit.
Repair short cir-
cuit in harness
between A/C con-
trol module and
ventilation motor
unit.
Repair short cir-
cuit in harness
between A/C con-
trol module and
ventilation motor
unit.