Subaru Legacy III (2000-2003 year). Manual — part 604

AT-150

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

10

CHECK HARNESS CONNECTOR BETWEEN
TCM AND SPORT SHIFT SWITCH.
1) Disconnect connector from TCM.
2) Measure resistance of harness between

TCM connector and SPORT shift switch
connector.

Connector & terminal

(B237) No. 5 — (B55) No. 15:

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

1

Ω

Go to step 11.

Repair open circuit
in harness
between SPORT
shift switch con-
nector and TCM
connector and
poor contact in
coupling connec-
tor.

11

CHECK HARNESS CONNECTOR BETWEEN
TCM AND SPORT SHIFT SWITCH.
1) Disconnect connector from TCM.
2) Measure resistance of harness between

SPORT shift switch connector and chassis
ground.

Connector & terminal

(B237) No. 5 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 12.

Repair short circuit
in harness
between SPORT
shift switch con-
nector and TCM
connector.

12

CHECK INPUT SIGNAL FOR TCM.
1) Connect connector to TCM and SPORT

shift switch.

2) Turn ignition switch to ON. (Engine is

stopped.)

3) Move select lever to normal mode.
4) Measure signal voltage for TCM.

Connector & terminal

(B55) No. 15 (+) — Chassis ground (–):

Does the measured value exceed the spec-
ified value?

9 V

Go to step 13.

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

13

CHECK INPUT SIGNAL FOR TCM.
1) Move select lever to SPORT shift mode.
2) Measure signal voltage for TCM.

Connector & terminal

(B55) No. 15 (+) — Chassis ground (–):

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

1 V

Go to step 35.

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

14

CHECK SPORT SHIFT SWITCH GROUND
LINE.
1) Turn ignition switch to OFF.
2) Disconnect connector from SPORT shift

switch.

3) Measure resistance of harness between

SPORT shift switch connector and chassis
ground.

Connector & terminal

(B237) No. 6 — Chassis ground:

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

1

Ω

Go to step 15.

Repair open circuit
in harness
between SPORT
shift switch and
chassis ground.

15

CHECK SPORT SHIFT SWITCH.
1) Measure resistance between SPORT shift

switch terminals.

Connector & terminal

(B237) No. 6 — No. 2:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 16.

Replace guide
plate assembly.

Step

Value

Yes

No

AT-151

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

16

CHECK SPORT SHIFT SWITCH.
1) Move select lever to SPORT shift mode.
2) Measure resistance between SPORT shift

switch terminals.

Connector & terminal

(B237) No. 6 — No. 2:

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

1

Ω

Go to step 17.

Replace guide
plate assembly.

17

CHECK HARNESS CONNECTOR BETWEEN
TCM AND SPORT SHIFT SWITCH.
1) Disconnect connector from TCM.
2) Measure resistance of harness between

TCM connector and SPORT shift switch
connector.

Connector & terminal

(B237) No. 2 — (B55) No. 13:

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

1

Ω

Go to step 18.

Repair open circuit
in harness
between SPORT
shift switch con-
nector and TCM
connector and
poor contact in
coupling connec-
tor.

18

CHECK HARNESS CONNECTOR BETWEEN
TCM AND SPORT SHIFT SWITCH.
1) Disconnect connector from steering roll

connector.

2) Measure resistance of harness between

SPORT shift switch connector and chassis
ground.

Connector & terminal

(B237) No. 2 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 19.

Repair short circuit
in harness
between SPORT
shift switch con-
nector and TCM
connector.

19

CHECK INPUT SIGNAL FOR TCM.
1) Connect all connectors.
2) Turn ignition switch to ON. (Engine is

stopped.)

3) Measure signal voltage for TCM.

Connector & terminal

(B55) No. 13 (+) — Chassis ground (–):

Does the measured value exceed the spec-
ified value?

9 V

Go to step 20.

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

20

CHECK INPUT SIGNAL FOR TCM.
1) Move select lever to shift up side.
2) Measure signal voltage for TCM.

Connector & terminal

(B55) No. 13 (+) — Chassis ground (–):

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

1 V

Go to step 35.

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

21

CHECK SPORT SHIFT SWITCH GROUND
LINE.
1) Turn ignition switch to OFF.
2) Disconnect connector from SPORT shift

switch.

3) Measure resistance of harness between

SPORT shift switch connector and chassis
ground.

Connector & terminal

(B237) No. 3 — Chassis ground:

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

1

Ω

Go to step 22.

Repair open circuit
in harness
between SPORT
shift switch and
chassis ground.

Step

Value

Yes

No

AT-152

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

22

CHECK SPORT SHIFT SWITCH.
Measure resistance between SPORT shift
switch terminals.

Connector & terminal

(B237) No. 3 — No. 1:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 24.

Replace guide
plate assembly.

23

CHECK SPORT SHIFT SWITCH.
1) Move select lever to SPORT shift mode.
2) Measure resistance between SPORT shift

switch terminals.

Connector & terminal

(B237) No. 3 — No. 1:

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

1

Ω

Go to step 24.

Replace guide
plate assembly.

24

CHECK HARNESS CONNECTOR BETWEEN
TCM AND SPORT SHIFT SWITCH.
1) Disconnect connector from TCM.
2) Measure resistance of harness between

TCM connector and SPORT shift switch
connector.

Connector & terminal

(B237) No. 1 — (B55) No. 2:

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

1

Ω

Go to step 25.

Repair open circuit
in harness
between SPORT
shift switch con-
nector and TCM
connector and
poor contact in
coupling connec-
tor.

25

CHECK HARNESS CONNECTOR BETWEEN
TCM AND SPORT SHIFT SWITCH.
1) Disconnect steering roll connector.
2) Measure resistance of harness between

SPORT shift switch connector and chassis
ground.

Connector & terminal

(B237) No. 1 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 26.

Repair short circuit
in harness
between SPORT
shift switch con-
nector and TCM
connector.

26

CHECK INPUT SIGNAL FOR TCM.
1) Connect all connectors.
2) Turn ignition switch to ON. (Engine is

stopped.)

3) Measure signal voltage for TCM.

Connector & terminal

(B55) No. 2 (+) — Chassis ground (–):

Does the measured value exceed the spec-
ified value?

9 V

Go to step 27.

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

27

CHECK INPUT SIGNAL FOR TCM.
1) Move select lever to shift up side.
2) Measure signal voltage for TCM.

Connector & terminal

(B55) No. 2 (+) — Chassis ground (–):

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

1 V

Go to step 35.

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

Step

Value

Yes

No

AT-153

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

28

CHECK ground circuit of steering shift
switch.
1) Turn ignition switch OFF.
2) Disconnect connector from steering roll

connector.

3) Measure resistance of harness between

steering roll connector and chassis ground.

Connector & terminal

(B68) No. 5 — Chassis ground:

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

1

Ω

Go to step 29.

Repair open circuit
between steering
roll connector and
body ground.

29

CHECK steering shift switch.
Measure resistance between steering roll con-
nector terminals.

Connector & terminal

(B68) No. 5 — No. 2:

Does the measured value exceed the the
specified value?

1 M

Ω

Go to step 30.

Replace steering
roll connector or
steering shift
switch. Repair
connector poor
contact.

30

CHECK steering shift switch.
1) Press steering shift switch + side and hold

it.

2) Measure resistance between terminals

between steering shift switch.

Connector & terminal

(B68) No. 5 — No. 2:

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

1

Ω

Go to step 31.

Replace steering
roll connector or
steering shift
switch. Repair
connector poor
contact.

31

CHECK harness connector between TCM
and Steering roll connector.
1) Disconnect connector from TCM.
2) Measure harness resistance between TCM

connector and steering roll connector.

Connector & terminal

(B55) No. 13 — (B68) No. 2:

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

1

Ω

The circuit is
returned to a nor-
mal condition.
Temporary poor
contact of the har-
ness may be the
case. Repair poor
contact of steering
roll connector and
steering shift
switch harness or
connector.

Repair poor con-
tact or harness
disconnection
between connec-
tors of TCM con-
nector and
steering roll con-
nector

32

CHECK Steering shift switch.
1) Turn ignition switch to OFF.
2) Disconnect connector from steering roll

connector.

3) Measure resistance value between steering

roll connectors.

Connector & terminal

(B68) No. 5 — No. 3:

Does the measured value exceed the spec-
ified value?

1

ΜΩ

Go to step 33.

Replace steering
roll connector or
steering shift
switch. Repair
connector poor
contact.

33

CHECK Steering shift switch.
1) Press steering shift switch + side and hold

it.

2) Measure resistance between terminals of

steering shift switch.

Connector & terminal

(B68) No. 5 — No. 3:

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

1

Ω

Go to step 34.

Replace steering
roll connector or
steering shift
switch. Repair
connector poor
contact.

Step

Value

Yes

No