Subaru Legacy III (2000-2003 year). Service manual — part 586

AT-78

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

5

CHECK POOR CONTACT.
Is there poor contact in shift solenoid 2 circuit?

There is poor contact.

Repair poor con-
tact.

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

6

CHECK SHIFT SOLENOID 2 (IN TRANSMIS-
SION).
1) Remove transmission connector from

bracket.

2) Drain automatic transmission fluid.

CAUTION:

Do not drain the automatic transmission flu-
id until it cools down.

3) Remove oil pan, and disconnect connector

from shift solenoid 2.

4) Measure resistance between shift solenoid

2 connector and transmission ground.

Connector & terminal

No. 1 — Transmission ground:

Is the measured value within the specified
range?

10 — 16

Ω

Go to step 7.

Replace shift sole-
noid 2 assembly.
<Ref. to AT-67,
Shift Solenoids,
Duty Solenoids
and ATF Temper-
ature Sensor.>

7

CHECK HARNESS CONNECTOR BETWEEN
SHIFT SOLENOID 2 AND TRANSMISSION.
Measure resistance of harness between shift
solenoid 2 and transmission connector.

Connector & terminal

(AT6) No. 1 — (T4) No. 2:

Is the measured value less than the specified
value?

1

Ω

Go to step 8.

Repair open circuit
in harness
between shift sole-
noid 2 and trans-
mission connector.

8

CHECK HARNESS CONNECTOR BETWEEN
SHIFT SOLENOID 2 AND TRANSMISSION.
Measure resistance of harness between shift
solenoid 2 connector and transmission ground.

Connector & terminal

(T4) No. 2 — Transmission ground:

Does the measured value exceed the specified
value?

1 M

Ω

Even if “POWER”
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
harness or con-
nector in shift sole-
noid 2 and
transmission.

Repair short circuit
harness between
shift solenoid 2
and transmission
connector.

Step

Value

Yes

No

AT-79

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

MEMO:

AT-80

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

K: DTC 73 LOW CLUTCH TIMING SOLENOID

DIAGNOSIS:
Output signal circuit of low clutch timing solenoid is open or shorted.
TROUBLE SYMPTOM:
Excessive shift shock.
WIRING DIAGRAM:

AT-00585

15

TRANSMISSION

B54

TCM

AT 9

LOW CLUTCH

TIMING

SOLENOID

B54

1 2

7

8

9

5 6

3 4

10 11 12
19 20 21

13

14 15

16

17

18

22

23

24

T4

B11

3

B11

1 2

5

6 7

8

13

14 15

16

9 10

11 12

3 4

17 18

19 20

AT-81

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Turn ignition switch to OFF.
2) Disconnect connector from TCM and trans-

mission.

3) Measure resistance of harness between

TCM and transmission connector.

Connector & terminal

(B54) No. 15 — (B11) No. 3:

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

1

Ω

Go to step 2.

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

2

CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure resistance of harness between TCM
connector and transmission ground.

Connector & terminal

(B54) No. 15 — Chassis ground:

Does the measured value exceed the specified
value?

1 M

Ω

Go to step 3.

Repair short circuit
in harness
between TCM and
transmission con-
nector.

3

CHECK LOW CLUTCH TIMING SOLENOID.
Measure resistance between transmission
connector terminals.

Connector & terminal

(T4) No. 3 — No. 16:

Is the measured value within the specified
range?

10 — 16

Ω

Go to step 4.

Go to step 7.

4

CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Connect connectors to TCM and transmis-

sion.

2) Turn ignition switch to ON (engine OFF).
3) Move select lever to “D” range.
4) Measure voltage between TCM connector

and chassis ground.

Connector & terminal

(B54) No. 15 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

9V

Go to step 5.

Go to step 6.

5

CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Hold switch to ON.
2) Measure voltage between TCM connector

and chassis ground.

Connector & terminal

(B54) No. 15 (+) — Chassis ground (

−−−−

):

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

1V

Even if “POWER”
indicator lights up,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
harness or con-
tact in the TCM
and transmission.

Go to step 6.

6

CHECK POOR CONTACT.
Is there poor contact in low clutch timing sole-
noid circuit?

There is poor contact.

Repair poor con-
tact.

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