Subaru Legacy III (2000-2003 year). Service manual — part 598

AT-126

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

F: CHECK KICK–DOWN SWITCH.

DIAGNOSIS:
• The kick-down switch is not ON when the throttle is fully open but is OFF when the throttle is partially open
or fully closed.
• Kick-down switch circuit is open or shorted.
TROUBLE SYMPTOM:
No kick-down occurs (when the throttle is fully open).
WIRING DIAGRAM:

Step

Value

Yes

No

1

CHECK KICK-DOWN SWITCH OPERATION.
When the accelerator pedal is depressed,
does “ON” displayed?

ON is displayed.

Go to step CHECK
POWER MODE
SWITCH. <Ref. to
AT-128, CHECK
POWER MODE
SWITCH., Diag-
nostic Procedure
for No-diagnostic
Trouble Code
(DTC).>

Go to step 2.

2

CHECK KICK-DOWN SWITCH GROUND
LINE.
1) Disconnect connector from kick-down

switch.

2) Measure resistance of harness connector

between kick-down switch and chassis
ground.

Connector & terminal

(B129) No. 1 — Chassis ground:

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

1

Ω

Go to step 3.

Repair open circuit
in harness
between kick-
down switch and
chassis ground.

AT-00594

E

B55

B55

TCM

KICK-DOWN

SWITCH

B129

1

2

B129

11

1 2 3 4

10 11 12
19 20 21

13

5 6

14 15

7

8

9

16

17

18

22

23

24

1
2

AT-127

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

3

CHECK KICK-DOWN SWITCH.
Measure resistance for kick-down switch when
depressing the accelerator pedal.

Terminals

No. 1 — No. 2:

Is the measured value less than the specified
value?

1

Ω

Go to step 4.

Replace kick-down
switch.

4

CHECK KICK-DOWN SWITCH.
Measure resistance for kick-down switch when
pressing the accelerator pedal.

Terminals

No. 1 — No. 2:

Does the measured value exceed the specified
value?

1 M

Ω

Go to step 5.

Replace kick-down
switch.

5

CHECK HARNESS CONNECTOR BETWEEN
TCM AND KICK-DOWN SWITCH.
1) Turn ignition switch OFF.
2) Disconnect connectors from kick-down

switch.

3) Measure resistance of harness connector

between TCM and kick-down switch.

Connector & terminal

(B55) No. 11 — (B129) No. 2:

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

1

Ω

Go to step 6.

Repair open circuit
in harness
between TCM and
kick-down switch.

6

CHECK HARNESS CONNECTOR BETWEEN
TCM AND KICK-DOWN SWITCH.
Measure resistance of harness connector
between TCM and chassis ground.

Connector & terminal

(B55) No. 11 — Chassis ground:

Does the measured value exceed the specified
value?

1 M

Ω

Go to step 7.

Repair short circuit
in harness
between TCM and
chassis ground.

7

CHECK INPUT SIGNAL FOR TCM.
1) Turn ignition switch to OFF.
2) Connect connector to kick-down switch.
3) Turn ignition switch ON (with engine OFF).
4) Measure signal voltage for TCM when

depressing the accelerator pedal.

Connector & terminal

(B55) No. 11 (+) — Chassis ground (

−−−−

):

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

1 V

Go to step 8.

Go to step 9.

8

CHECK INPUT SIGNAL FOR TCM.
Measure signal voltage for TCM when press-
ing the accelerator pedal.

Connector & terminal

(B55) No. 11 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the specified
value?

6.5 V

A temporary poor
contact of the con-
nector and har-
ness may be the
cause. Repair har-
ness and connec-
tor in the TCM.

Go to step 9.

9

CHECK POOR CONTACT.
Is there poor contact?

There is poor contact.

Repair poor con-
tact.

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

Step

Value

Yes

No

AT-128

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

G: CHECK POWER MODE SWITCH.

DIAGNOSIS:
• LED does not come on when power switch is ON.
• Power switch circuit is open or shorted.
TROUBLE SYMPTOM:
No power mode occurs.
WIRING DIAGRAM:

AT-00787

BATTERY

No.5

IGNITION

RELAY

i11

1 2 3 4

5 6 7

8 9 10 11 12 13 14 15 16

i12

1 2 3

4 5 6

7 8 9 10 11 12 13 14

B55

TCM

B:

B56

B133

C:

POWER

MODE

SWITCH

ON

OFF

E

E

B55

B56

1 2 3 4

10 11 12
19 20 21

13

5 6

14 15

7

8

9

16

17

18

22

23

24

1 2 3 4

10 11 12
19 20 21

13

5 6

14 15

7

8

9

16

17

18

22

23

24

COMBINATION
METER

i10

A:

i11

B:

i12

C:

i1

B36

B12

H6L

A8

B6

H4N

C3

B5

P5

POWER

H6RT : RHD 3.0L MODEL AND TURBO MODEL

H6L : LHD 3.0L MODEL

H4N : EXCEPT 3.0L MODEL AND TURBO MODEL

: 3.0L MODEL AND TURBO MODEL

H6

H6

B36

B4 B5 B6

A4 A5 A6

C5 C6

F6

D4 D5 D6

F1

H1

C4

G6

G1

C2

K1

M1 M2

K6

L1

D1 D2

A1 A2
B1 B2

I6

J6

L2

I1

J1

H6

M4 M5 M6

L4 L5 L6

N5 N6

O4 O5 O6

N4

P4 P5

N2

O1 O2

P1 P2

N3

O3

P3

P6

A3

B3

C3

E4 E5 E6

E1 E2

i10

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

B133

1

2

3 4 5 6

A13

H6RT

B5

A8

C11

B23

3

4

AT-129

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK POWER SWITCH OPERATION.
When power switch is turned OFF, does LED
light up?

LED lights up.

Go to step 5.

Go to step 2.

2

CHECK POWER SWITCH OPERATION.
When power switch is turned ON, does LED
light up?

LED lights up.

Go to step CHECK
INHIBITOR
SWITCH. <Ref. to
AT-132, CHECK
INHIBITOR
SWITCH., Diag-
nostic Procedure
for No-diagnostic
Trouble Code
(DTC).>

Go to step 3.

3

CHECK POWER INDICATOR LIGHT.
1) Turn ignition switch to OFF.
2) Remove combination meter.
3) Remove POWER indicator light bulb from

combination meter.
Is POWER indicator light bulb OK?

Bulb is normal.

Go to step 4.

Replace POWER
indicator light bulb.
<Ref. to IDI-14,
Combination
Meter Assembly.>

4

CHECK POWER SWITCH GROUND LINE.
1) Turn ignition switch to OFF.
2) Disconnect connector from power switch.
3) Measure resistance of harness connector

between power switch and chassis ground.

Connector & terminal

(B133) No. 4 — Chassis ground:

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

1

Ω

Go to step 5.

Repair open circuit
in harness
between power
switch and chassis
ground.

5

CHECK POWER SWITCH.
1) Power switch turned ON.
2) Measure resistance between terminals of

power switch.

Terminals

No. 3 — No. 4:

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

1

Ω

Go to step 6.

Repair power
switch.

6

CHECK POWER SWITCH.
1) Power switch turned OFF.
2) Measure resistance between terminals of

power switch.

Terminals

No. 3 — No. 4:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 7.

Repair power
switch.

7

CHECK HARNESS CONNECTOR BETWEEN
TCM AND POWER SWITCH.
Measure resistance of harness connector
between TCM and power switch.

Connector & terminal

(B55) No. 23 — (B133) No. 3:

Is the measured value less than the specified
value?

1

Ω

Go to step 8.

Repair open circuit
in harness
between TCM and
power switch con-
nector.