Subaru Legacy III (2000-2003 year). Manual - part 600

AT-134

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

20

CHECK INDICATOR LIGHT.
Does combination meter “1” range indicator 
illuminate?

1 range indicator lights up.

Go to step 21.

Go to step 62.

21

CHECK “1” RANGE SWITCH.
When the “2” range is selected, does “1” range 
LED light UP?

LED lights up.

Go to step 64.

Go to step CHECK 
HOLD SWITCH. 
<Ref. to AT-144, 
CHECK HOLD 
SWITCH., Diag-
nostic Procedure 
for No-diagnostic 
Trouble Code 
(DTC).>  

22

CHECK HARNESS CONNECTOR BETWEEN 
INHIBITOR SWITCH AND CHASSIS 
GROUND.
1) Turn ignition switch to OFF.
2) Disconnect connector from inhibitor switch.
3) Measure resistance of harness between 

inhibitor switch and chassis ground.

Connector & terminal

(T7) No. 5 — Chassis ground:

Is the measured value less than the speci-
fied value?

1 

Ω

Go to step 23.

Repair open circuit 
in harness 
between inhibitor 
switch connector 
and chassis 
ground, and poor 
contact in cou-
pling connector.

23

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn ignition switch to OFF.
2) Disconnect connectors from TCM and 

inhibitor switch.

3) Measure resistance of harness between 

TCM and inhibitor switch connector.

Connector & terminal

(B55) No. 1 — (T7) No. 9

Is the measured value less than the speci-
fied value?

1 

Ω

Go to step 24.

Repair open circuit 
in harness 
between TCM and 
inhibitor switch 
connector, and 
poor contact in 
coupling connec-
tor.

24

CHECK INPUT SIGNAL FOR TCM.
1) Turn ignition switch to OFF.
2) Connect connector to TCM and inhibitor 

switch.

3) Turn ignition switch to ON.
4) Move select lever to P range.
5) Measure voltage between TCM and chas-

sis ground.

Connector & terminal

(B55) No. 1 (+) — Chassis ground (–):

Is the measured value less than the speci-
fied value?

1 V

Go to step 25.

Go to step 65.

25

CHECK INPUT SIGNAL FOR TCM.
1) Position select lever to any other than P 

range.

2) Measure voltage between TCM and chas-

sis ground.

Connector & terminal

(B55) No. 1 (+) — Chassis ground (–):

Does the measured value exceed the spec-
ified value?

8 V

Go to step 65.

Replace TCM. 
<Ref. to AT-76, 
Transmission Con-
trol Module 
(TCM).>

Step

Value

Yes

No

AT-135

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

26

CHECK “P” RANGE INDICATOR LIGHT 
BULB.
1) Turn ignition switch to OFF.
2) Remove combination meter.
3) Remove “P” range indicator light bulb from 

combination meter.
Is “P” range indicator light bulb OK?

Bulb is normal.

Go to step 27.

Replace “P” range 
indicator light bulb. 
<Ref. to IDI-14, 
Combination 
Meter Assembly.>

27

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND COMBINATION METER.
1) Disconnect connectors from TCM and com-

bination meter.

2) Measure resistance of harness between 

TCM and combination meter.

Connector & terminal

Except 3.0 L model and TURBO model:

(B55) No. 1 — (i11) No. 1:

3.0 L model and TURBO model:

(B55) No. 1 — (i10) No. 14:

Does the measured value exceed the spec-
ified value?

1 

Ω

Go to step 65.

Repair open circuit 
in harness 
between inhibitor 
switch connector 
and combination 
meter, and poor 
contact in cou-
pling connector.

28

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn ignition switch to OFF.
2) Disconnect connectors from TCM, inhibitor 

switch and combination meter.

3) Measure resistance of harness between 

TCM and chassis ground.

Connector & terminal

(B55) No. 1 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 29.

Repair ground 
short circuit in “P” 
range circuit.

29

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn ignition switch to OFF.
2) Disconnect connectors from TCM and 

inhibitor switch.

3) Measure resistance of harness between 

TCM and inhibitor switch connector.

Connector & terminal

(B55) No. 3 — (T7) No. 8:

Is the measured value less than the speci-
fied value?

1 

Ω

Go to step 30.

Repair open circuit 
in harness 
between TCM and 
inhibitor switch 
connector, and 
poor contact in 
coupling connec-
tor.

30

CHECK INPUT SIGNAL FOR TCM.
1) Turn ignition switch to OFF.
2) Connect connector to TCM and inhibitor 

switch.

3) Turn ignition switch to ON.
4) Move select lever to R range.
5) Measure voltage between TCM and chas-

sis ground.

Connector & terminal

(B55) No. 3 (+) — Chassis ground (–):

Is the measured value less than the speci-
fied value?

1 V

Go to step 31.

Go to step 65.

Step

Value

Yes

No

AT-136

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

31

CHECK INPUT SIGNAL FOR TCM.
1) Position select lever to any other than R 

range.

2) Measure voltage between TCM and chas-

sis ground.

Connector & terminal

(B55) No. 3 (+) — Chassis ground (–):

Does the measured value exceed the spec-
ified value?

8 V

Go to step 65.

Replace TCM. 
<Ref. to AT-76, 
Transmission Con-
trol Module 
(TCM).>

32

CHECK “R” RANGE INDICATOR LIGHT 
BULB.
1) Turn ignition switch to OFF.
2) Remove combination meter.
3) Remove “R” range indicator light bulb from 

combination meter.
Is “R” range indicator light bulb OK?

Bulb is normal.

Go to step 33.

Replace “R” range 
indicator light bulb. 
<Ref. to IDI-14, 
Combination 
Meter Assembly.>

33

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND COMBINATION METER.
1) Disconnect connectors from TCM and com-

bination meter.

2) Measure resistance of harness between 

TCM and combination meter.

Connector & terminal

Except 3.0 L model and TURBO model:

(B55) No. 3 — (i11) No. 2:

3.0 L model and TURBO model:

(B55) No. 3 — (i10) No. 22:

Is the measured value less than the speci-
fied value?

1 

Ω

Go to step 65.

Repair open circuit 
in harness 
between TCM 
connector and 
combination 
meter, and poor 
contact in TCM 
connector.

34

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn ignition switch to OFF.
2) Disconnect connectors from TCM, inhibitor 

switch and combination meter.

3) Measure resistance of harness between 

TCM and chassis ground.

Connector & terminal

(B55) No. 3 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 35.

Repair ground 
short circuit in “R” 
range circuit.

35

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn ignition switch to OFF.
2) Disconnect connectors from TCM and 

inhibitor switch.

3) Measure resistance of harness between 

TCM and inhibitor switch connector.

Connector & terminal

(B55) No. 14 — (T7) No. 10:

Is the measured value less than the speci-
fied value?

1 

Ω

Go to step 36.

Repair open circuit 
in harness 
between TCM and 
inhibitor switch 
connector, and 
poor contact in 
coupling connec-
tor.

Step

Value

Yes

No

AT-137

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

36

CHECK INPUT SIGNAL FOR TCM.
1) Turn ignition switch to OFF.
2) Connect connector to TCM and inhibitor 

switch.

3) Turn ignition switch to ON.
4) Move select lever to N range.
5) Measure voltage between TCM and chas-

sis ground.

Connector & terminal

(B55) No. 14 (+) — Chassis ground (–):

Is the measured value less than the speci-
fied value?

1 V

Go to step 37.

Go to step 65.

37

CHECK INPUT SIGNAL FOR TCM.
1) Position select lever to any other than N 

range.

2) Measure voltage between TCM and chas-

sis ground.

Connector & terminal

(B55) No. 14 (+) — Chassis ground (–):

Does the measured value exceed the spec-
ified value?

8 V

Go to step 65.

Replace TCM. 
<Ref. to AT-76, 
Transmission Con-
trol Module 
(TCM).>

38

CHECK “N” RANGE INDICATOR LIGHT 
BULB.
1) Turn ignition switch to OFF.
2) Remove combination meter.
3) Remove “N” range indicator light bulb from 

combination meter.
Is “N” range indicator light bulb OK?

Bulb is normal.

Go to step 39.

Replace “N” range 
indicator light bulb. 
<Ref. to IDI-14, 
Combination 
Meter Assembly.>

39

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND COMBINATION METER.
1) Disconnect connectors from TCM and com-

bination meter.

2) Measure resistance of harness between 

TCM and combination meter.

Connector & terminal

Except 3.0 L model and TURBO model:

(B55) No. 14 — (i11) No. 3:

3.0 L model and TURBO model:

(B55) No. 14 — (i10) No. 21:

Does the measured value exceed the spec-
ified value?

1 

Ω

Go to step 65.

Repair open circuit 
in harness 
between inhibitor 
switch connector 
and combination 
meter.

40

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND INHIBITOR SWITCH.
1) Turn ignition switch to OFF.
2) Disconnect connectors from TCM, inhibitor 

switch and combination meter.

3) Measure resistance of harness between 

TCM and chassis ground.

Connector & terminal

(B55) No. 14 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 41.

Repair ground 
short circuit in “N” 
range circuit.

Step

Value

Yes

No