Subaru Legacy III (2000-2003 year). Service 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