Subaru Legacy III (2000-2003 year). Manual - part 603

AT-146

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

8

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND COMBINATION METER.
Measure resistance of harness connector TCM 
and combination meter.

Connector & terminal

Except 3.0 L model and TURBO model:

(B55) No. 16 — (i12) No. 2:

3.0 L model and TURBO model:

(B55) No. 16 — (i10) No. 12:

Is the measured value less than the specified 
value?

1 

Ω

Go to step 9.

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

9

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND HOLD SWITCH.
Measure resistance of harness connector 
between TCM and chassis ground to make 
sure that circuit does not short.

Connector & terminal

(B55) No. 16 — Chassis ground:

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 10.

Repair short circuit 
in harness 
between TCM, 
hold switch and 
combination meter 
connector.

10

CHECK INPUT SIGNAL FOR TCM.
1) Connect connectors to TCM and hold 

switch.

2) Turn ignition switch ON (with engine OFF).
3) Measure signal voltage for TCM while turn-

ing hold switch OFF.

Connector & terminal

(B55) No. 16 (+) — Chassis ground (–):

Does the measured value exceed the spec-
ified value?

8 V

Go to step 11.

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

11

CHECK INPUT SIGNAL FOR TCM.
Measure signal voltage for TCM while turning 
hold switch ON.

Connector & terminal

(B55) No. 16 (+) — Chassis ground (–):

Is the measured value less than the specified 
value?

1 V

Go to step 12.

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

12

CHECK POOR CONTACT.
Is there poor contact?

There is poor contact.

Repair poor con-
tact.

A temporary poor 
contact of the con-
nector or harness 
or connector in 
hold switch circuit.

Step

Value

Yes

No

AT-147

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

MEMO:

AT-148

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

J: CHECK SPORT SHIFT SWITCH.

DIAGNOSIS:
SPORT shift switch input signal circuit is open or shorted.
TROUBLE SYMPTOM:
• No SPORT shift mode occurs.
• Does not shift gears in SPORT shift mode.
WIRING DIAGRAM:

STEERING 
SHIFT SWITCH

AT-00790

15

4

B55

TCM

B237

SPORT SHIFT
SWITCH

B237

1

2

3 4 5 6

B55

1 2

7

8

9

5 6

3 4

10 11 12
19 20 21

13

14 15

16

17

18

22

23

24

SPOR

T SHIFT

MODE SWITCH

6

UP SHIFT

SWITCH

3

5

2

1

13

2

DO

WN SHIFT

SWITCH

B68

1

2

3 4 5

LH

UP

DOWN

B68

3

5

2

STEERING 
ROLL
CONNECTOR

RH

UP

DOWN

AT-149

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK VEHICLE.
Is the target model equipped with SPORT 
shift?

Model with sport shift

Go to step 2.

Go to step SYMP-
TOM RELATED 
DIAGNOSTIC. 
<Ref. to AT-160, 
Symptom Related 
Diagnostic.>

2

CHECK SPORT SHIFT SWITCH.
Does LED light up when select lever is moved 
to SPORT shift mode?

Lights up.

Go to step 3.

Go to step 7.

3

CHECK SPORT SHIFT SWITCH.
Does LED light up when select lever is moved 
to shift up side?

Lights up.

Go to step 4.

Go to step 14.

4

CHECK SPORT SHIFT SWITCH.
Does LED light up when select lever is moved 
to shift down side?

Lights up.

Go to step 5.

Go to step 21.

5

CHECK STEERING SHIFT SWITCH.
Does LED light up when steering shift switch + 
side is pressed?

Lights up.

Go to step 6.

Go to step 28.

6

CHECK STEERING SHIFT SWITCH.
Does LED light up when steering shift switch – 
side is pressed?

Lights up.

Go to “Inspection 
of SPORT shift 
indicator” proce-
dures. <Ref. to 
AT-156, CHECK 
SPORT SHIFT 
INDICATOR., 
Diagnostic Proce-
dure for No-diag-
nostic Trouble 
Code (DTC).> 

Go to step 32.

7

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. 4 —- Chassis ground:

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

1 

Ω

Go to step 8.

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

8

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

Connector & terminal

(B237) No. 4 —- No. 5:

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 9.

Replace lever 
plate assembly.

9

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

switch terminals.

Connector & terminal

(B237) No. 4 — No. 5:

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

1 

Ω

Go to step 10.

Replace lever 
plate assembly.