Subaru Legacy 2002 Service Manual page 3222

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC) (RHD
No.
1 CHECK AIR MIX MOTOR.
1) Turn ignition switch to OFF.
2) Remove air mix motor unit.
3) Make sure that air mix motor is operated
when connecting battery to air mix motor.
Terminals:
Battery positive terminal — (D) No. 6
Battery negative terminal — (D) No. 7
2 CHECK POTENTIOMETER.
Measure resistance for the power supply line
of the potentiometer.
Terminals:
(D) No. 1 — No. 3
3 CHECK POTENTIOMETER.
Measure resistance for the signal line of the
potentiometer, when the lever is in the MAX
COOL position.
Terminals:
(D) No. 1 — No. 5
4 CHECK POTENTIOMETER.
Measure resistance for the signal line of the
potentiometer, when the lever is in the MAX
HOT position.
Terminals:
(D) No. 1 — No. 5
5 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
AIR MIX MOTOR UNIT.
1) Disconnect connector from A/C control
module.
2) Measure resistance of harness between
A/C control module and air mix motor unit.
Connector & terminal:
(i48) No. 6 — (D) No. 5
6 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
AIR MIX MOTOR UNIT.
Measure resistance of harness between A/C
control module and air mix motor unit.
Connector & terminal:
(i48) No. 5 — (D) No. 3
7 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
AIR MIX MOTOR UNIT.
Measure resistance of harness between A/C
control module and air mix motor unit.
Connector & terminal:
(i48) No. 10 — (D) No. 1
8 CHECK HARNESS CONNECTOR
BETWEEN A/C CONTROL MODULE AND
AIR MIX MOTOR UNIT.
Measure resistance of harness between A/C
control module and air mix motor unit.
Connector & terminal:
(i49) No. 1 — (D) No. 6
MODEL)
Step
Does the air mix 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-79
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 air mix
motor unit.
Replace air mix
motor unit.
Replace air mix
motor unit.
Replace air mix
motor unit.
Repair short cir-
cuit in harness
between A/C con-
trol module and
air mix motor unit.
Repair short cir-
cuit in harness
between A/C con-
trol module and
air mix motor unit.
Repair short cir-
cuit in harness
between A/C con-
trol module and
air mix motor unit.
Repair short cir-
cuit in harness
between A/C con-
trol module and
air mix motor unit.