Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 605

AC(diag)-25

Diagnostic Procedure for Actuators

HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)

B: MODE DOOR ACTUATOR

TROUBLE SYMPTOM:

Air flow outlet is not changed.

WIRING DIAGRAM:

Air conditioning system, auto A/C model <Ref. to WI-77, AUTO A/C MODEL, WIRING DIAGRAM, Air Con-

ditioning System.>

3

CHECK OPERATION OF INTAKE DOOR AC-
TUATOR.
1) Connect the intake door actuator connector.
2) Ground the auto A/C control module con-
nector with a suitable wire.
3) Turn the ignition switch to ON, and check the
operation of intake door actuator.

Connector & terminal

(i88) No. 6 — Chassis ground:

Does the actuator move to the
FRESH side?

Go to step

4.

Replace the intake
door actuator.

4

CHECK OPERATION OF INTAKE DOOR AC-
TUATOR.
1) Turn the ignition switch to OFF.
2) Ground the auto A/C control module con-
nector with a suitable wire.
3) Turn the ignition switch to ON, and check the
operation of intake door actuator.

Connector & terminal:

(i88) No. 8 — Chassis ground:

Does the actuator move to the
RECIRC side?

Replace the auto
A/C control mod-
ule. <Ref. to AC-
31, REMOVAL,
Control Unit (Auto
A/C Model).>

Replace the intake
door actuator.

Step

Check

Yes

No

i1

5 6 7 8

2

1

9

4

3

10

24

22

23

25

27

26

28

11 12 13

14 15 16

17 18 19 20 21

25

20

22

21

2

5

1

6

B77

4

3

2

1

i88

3

i1

B36

B77

1 2
3 4
5 6

i88

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

AC-02429

TO POWER

SUPPLY CIRCUIT

FB-18

F/B FUSE NO. 7

(B)

AUTO A/C

CONTROL

MODULE

MODE DOOR

ACTUATOR

AC(diag)-26

Diagnostic Procedure for Actuators

HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK POWER SUPPLY FOR MODE DOOR
ACTUATOR.
1) Turn the ignition switch to OFF.
2) Disconnect the mode door actuator connec-
tor.
3) Turn the ignition switch to ON.
4) Measure the voltage between the mode
door actuator connector terminal and chassis
ground.

Connector & terminal

(B77) No. 3 (+) — Chassis ground (–):

Is the voltage approx. 10 V or
more?

Go to step

2.

Check the DC
power supply cir-
cuit.

2

CHECK MODE DOOR ACTUATOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between mode door
actuator terminals using a tester.

Connector & terminal

(B77) No. 3 — No. 1:
(B77) No. 3 — No. 2:
(B77) No. 3 — No. 5:
(B77) No. 3 — No. 6:

Is the resistance 80 — 100 Ω? Go to step

3.

Replace the mode
door actuator.

3

CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND MODE DOOR AC-
TUATOR.
1) Disconnect the auto A/C control module
connector.
2) Measure the resistance between auto A/C
control module and mode door actuator con-
nector.

Connector & terminal

(B77) No. 1 — (i88) No. 4:
(B77) No. 2 — (i88) No. 3:
(B77) No. 5 — (i88) No. 2:
(B77) No. 6 — (i88) No. 1:

Is the resistance less than 1 Ω? Go to step

4.

Repair the harness
between auto A/C
control module and
mode door actua-
tor.

4

CHECK FOR POOR CONTACT.
Check poor contact of auto A/C control module
and connector.

Is there poor contact of connec-
tor?

Repair the connec-
tor.

Replace the auto
A/C control mod-
ule. <Ref. to AC-
31, REMOVAL,
Control Unit (Auto
A/C Model).>

AC(diag)-27

Diagnostic Procedure for Actuators

HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)

C: AIR MIX DOOR ACTUATOR

TROUBLE SYMPTOM:

Outlet air temperature does not change.

WIRING DIAGRAM:

Air conditioning system, auto A/C model <Ref. to WI-77, AUTO A/C MODEL, WIRING DIAGRAM, Air Con-

ditioning System.>

Step

Check

Yes

No

1

CHECK POWER SUPPLY OF AIR MIX DOOR
ACTUATOR.
1) Turn the ignition switch to OFF.
2) Disconnect the air mix door actuator con-
nector.
3) Turn the ignition switch to ON.
4) Measure the voltage between the air mix
door actuator connector terminal and chassis
ground.

Connector & terminal

(B239) No. 3 (+) — Chassis ground (–):

Is the voltage approx. 10 V or
more?

Go to step

2.

Check the DC
power supply cir-
cuit.

2

CHECK AIR MIX DOOR ACTUATOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between air mix
door actuator terminals using a tester.

Connector & terminal

(B239) No. 3 — No. 1:
(B239) No. 3 — No. 2:
(B239) No. 3 — No. 5:
(B239) No. 3 — No. 6:

Is the resistance 80 — 100 Ω? Go to step

3.

Replace the air mix
door actuator.

i1

5 6 7 8

2

1

9

4

3

10

24

22

23

25

27

26

28

11 12 13

14 15 16

17 18 19 20 21

19

27

1

8

2

8

2

5

1

6

B239

2

8

27

26

25

i88

i1

B36

1 2
3 4
5 6

B239

i88

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

3

AC-02430

TO POWER

SUPPLY CIRCUIT

FB-18

F/B FUSE NO. 7

(B)

AUTO A/C

CONTROL

MODULE

AIR MIX DOOR

ACTUATOR

AC(diag)-28

Diagnostic Procedure for Actuators

HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)

3

CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND AIR MIX DOOR
ACTUATOR.
1) Disconnect the auto A/C control module
connector.
2) Measure the resistance between auto A/C
control module and air mix door actuator con-
nector.

Connector & terminal

(B239) No. 1 — (i88) No. 28:
(B239) No. 2 — (i88) No. 27:
(B239) No. 5 — (i88) No. 26:
(B239) No. 6 — (i88) No. 25:

Is the resistance less than 1 Ω? Go to step

4.

Repair the harness
between auto A/C
control module and
air mix door actua-
tor.

4

CHECK FOR POOR CONTACT.
Check poor contact of auto A/C control module
and connector.

Is there poor contact of connec-
tor?

Repair the connec-
tor.

Replace the auto
A/C control mod-
ule. <Ref. to AC-
31, REMOVAL,
Control Unit (Auto
A/C Model).>

Step

Check

Yes

No