Subaru Legacy (2005 year). Manual — part 552

4AT(diag)-45

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM.
3) Measure the resistance between TCM con-
nector terminals.

Connector & terminal

(B54) No. 21 — No. 9:

Is the resistance more than
500

Ω?

Go to step 2.

Go to step 4.

2

CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.

Connector & terminal

(B54) No. 21 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 3.

Go to step 4.

3

CHECK HARNESS.
Measure the resistance between TCM connec-
tor terminals while shaking the harness.

Connector & terminal

(B54) No. 21 — No. 9:

Does the resistance change?

Go to step 4.

Replace the TCM.
<Ref. to 4AT-66,
Transmission Con-
trol Module
(TCM).>

4

CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion.
3) Measure the resistance of harness
between TCM connector and chassis ground.

Connector & terminal

(B54) No. 21 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 5.

Repair the short
circuit of harness
between TCM and
transmission har-
ness.

5

CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.

Connector & terminal

(B54) No. 9 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 6.

Repair the short
circuit of harness
between TCM and
transmission har-
ness.

6

CHECK ATF TEMPERATURE SENSOR.
Measure the resistance between transmission
connector terminals.

Connector & terminal

(T4) No. 11 — No. 15:

Is the resistance more than
500

Ω?

Even if the SPORT
indicator light is
blinking, the cir-
cuit has returned
to normal condi-
tion at this time. A
temporary short
circuit of connector
or harness may be
the cause. Repair
the harness or
connector.

Go to step 7.

4AT(diag)-46

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

7

CHECK TRANSMISSION HARNESS.
1) Lift-up the vehicle.
2) Drain the ATF.

CAUTION:

Do not drain ATF until it cools down.

3) Remove the oil pan.
4) Disconnect the harness connector from
control valve.
5) Measure the resistance between ATF tem-
perature sensor connector terminals
6) Measure the resistance between transmis-
sion connector and transmission ground.

Connector & terminal

(T4) No. 11 — Transmission ground:

Is the resistance more than 1
M

Ω?

Go to step 8.

Replace the trans-
mission harness.

8

CHECK TRANSMISSION HARNESS.
Measure the resistance between transmission
connector and transmission ground.

Connector & terminal

(T4) No. 15 — Transmission ground:

Is the resistance more than 1
M

Ω?

Go to step 9.

Replace the trans-
mission harness.

9

CHECK ATF TEMPERATURE SENSOR.
Measure the resistance between control valve
connector terminals

Terminal

No. 1 — No. 3:

Is the resistance more than
500

Ω?

Even if the SPORT
indicator light is
blinking, the cir-
cuit has returned
to normal condi-
tion at this time. A
temporary short
circuit of connector
or harness may be
the cause. Repair
the harness or
connector.

Replace the con-
trol valve body.
<Ref. to 4AT-62,
Control Valve
Body.>

Step

Check

Yes

No

4AT(diag)-47

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

D: DTC P0715 INPUT/TURBINE SPEED SENSOR CIRCUIT

DTC DETECTING CONDITION:
Input signal circuit of TCM is open or shorted.
TROUBLE SYMPTOM:
Excessive shift shock
WIRING DIAGRAM:

AT-03157

RH LH

RH

LH

5

10

B11

T4

TCM

B54

7

B11

1

2

3 4

5

6 7

8

9

13

14 15

20

19

17

16

10

11 12

18

B54

TORQUE
CONVERTER
TURBINE SPEED
SENSOR

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

B53

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

16

B53

JOINT
CONNECTOR

: LHD MODEL

RH

LH

: RHD MODEL

*

: TERMINAL No. RANDOM ARRANGEMENT
AMONG 2,3, AND 13

* *

*

*

*

*

4AT(diag)-48

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK TORQUE CONVERTER TURBINE
SPEED SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion.
3) Measure the resistance between transmis-
sion connector receptacle’s terminals.

Connector & terminal

(T4) No. 5 — No. 10:

Is the resistance 450 — 650
Ω?

Go to step 2.

Replace the
torque converter
turbine speed sen-
sor. <Ref. to 4AT-
59, Torque Con-
verter Turbine
Speed Sensor.>

2

CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Disconnect the connector from TCM.
2) Measure the resistance of harness
between TCM and transmission connector.

Connector & terminal

(B54) No. 7 — (B11) No. 5:

Is the resistance less than 1
Ω?

Go to step 3.

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

3

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

Connector & terminal

(B54) No. 16 — (B11) No. 10:

Is the resistance less than 1
Ω?

Go to step 4.

Repair the open
circuit of harness
between TCM and
transmission con-
nector, and poor
contact in connec-
tor.

4

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

Connector & terminal

(B54) No. 16 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 5.

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

5

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

Connector & terminal

(B54) No. 7 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 6.

Repair the short
circuit of harness
between TCM and
transmission con-
nector, and poor
contact in connec-
tor.

6

CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and trans-
mission.
2) Connect the Subaru Select Monitor to data
link connector.
3) Turn the ignition switch to ON and the Sub-
aru Select Monitor power switch to ON.
4) Start the engine.
5) Shift the select lever to “P” or “N” range.
6) Read the data of turbine speed using Sub-
aru Select Monitor.
• Compare the tachometer with Subaru Select
Monitor indications.

Is the revolution value same as
the tachometer reading shown
on the combination meter?

Even if the SPORT
indicator light is
blinking, the cir-
cuit has returned
to normal condi-
tion at this time. A
temporary poor
contact of connec-
tor or harness may
be the cause.
Repair the har-
ness or connector
in TCM and trans-
mission.

Go to step 7.

7

CHECK POOR CONTACT.

Is there poor contact in torque
converter turbine speed sensor
circuit?

Repair the poor
contact.

Replace the TCM.
<Ref. to 4AT-66,
Transmission Con-
trol Module
(TCM).>