Subaru Legacy (2005 year). Manual — part 551

4AT(diag)-41

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

B: DTC P0712 TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT LOW

INPUT

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

AT-02227

B11

B54

AT2

1

2

3 4

5

6 7

8

9

13

14 15

20

19

17

16

10

11 12

18

21

9

15

11

3

1

B54

B11

AT2

T4

TCM

3 4

1 2

1 2

7

8 9

5

6

3

4

10 11 12

19 20 21

13 14 15 16

17 18

22 23 24

ATF TEMPERATURE

SENSOR

TRANSMISSION

4AT(diag)-42

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 transmis-
sion and TCM.
3) Measure the resistance of harness
between TCM and transmission connector.

Connector & terminal

(B54) No. 21 — (B11) No. 11:

Is the resistance less than 1
Ω?

Go to step 2.

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

2

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

Connector & terminal

(B54) No. 9 — (B11) No. 15:

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 ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to OFF.
2) Connect the connectors to transmission
and TCM.
3) Turn the ignition switch to ON and start
engine.
4) Warm-up the transmission until the ATF
temperature exceeds 80

°C (176°F).

NOTE:

If the ambient temperature is below 0

°C (32°F),

drive the vehicle until the ATF reaches its oper-
ating temperature.

5) Disconnect the connector from transmis-
sion.
6) Measure the resistance between transmis-
sion connector terminals.

Connector & terminal

(T4) No. 11 — No. 15:

Is the resistance 300 — 800
Ω?

Go to step 4.

Go to step 7.

4

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

Connector & terminal

(T4) No. 11 — No. 15:

Does the resistance value
increase while the ATF temper-
ature decreases?

Go to step 5.

Go to step 7.

5

CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connector to transmission.
2) Connect the Subaru Select Monitor to data
link connector.
3) Turn the ignition switch to ON (engine
OFF).
4) Read the data of ATF temperature using
Subaru Select Monitor.

Does the ATF temperature
gradually decrease?

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 contact in
the ATF tempera-
ture sensor and
transmission con-
nector.

Go to step 6.

6

CHECK POOR CONTACT.

Is there poor contact in ATF
temperature sensor circuit?

Repair the poor
contact.

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

4AT(diag)-43

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

7

CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND ATF TEMPERATURE
SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion.
3) Remove the transmission connector from
bracket.
4) Lift-up the vehicle.

NOTE:

Raise all wheels off floor.

5) Drain the ATF.

CAUTION:

Do not drain ATF until it cools down.

6) Remove the oil pan, and disconnect the
connector from control valve.
7) Measure the resistance of harness
between ATF temperature sensor and trans-
mission connector.

Connector & terminal

(T4) No. 11 — (AT2) No. 1:

Is the resistance less than 1
Ω?

Go to step 8.

Repair the open
circuit of harness
between ATF tem-
perature sensor
and transmission
connector.

8

CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND ATF TEMPERATURE
SENSOR.
Measure the resistance of harness between
ATF temperature sensor and transmission con-
nector.

Connector & terminal

(T4) No. 15 — (AT2) No. 3:

Is the resistance less than 1
Ω?

Go to step 9.

Repair the open
circuit of harness
between ATF tem-
perature sensor
and transmission
connector.

9

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

Connector & terminal

(T4) No. 11 — Transmission ground:

Is the resistance more than 1
M

Ω?

Go to step 10.

Repair the short
circuit of harness
between ATF tem-
perature sensor
and transmission
connector.

10

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

Connector & terminal

(T4) No. 15 — Transmission ground:

Is the resistance more than 1
M

Ω?

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

Repair the short
circuit of harness
between ATF tem-
perature sensor
and transmission
connector.

Step

Check

Yes

No

4AT(diag)-44

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

C: DTC P0713 TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT HIGH

INPUT

DTC DETECTING CONDITION:
Input signal circuit of TCM to ATF temperature sensor is shorted.
TROUBLE SYMPTOM:
Excessive shift shock
WIRING DIAGRAM:

AT-02227

B11

B54

AT2

1

2

3 4

5

6 7

8

9

13

14 15

20

19

17

16

10

11 12

18

21

9

15

11

3

1

B54

B11

AT2

T4

TCM

3 4

1 2

1 2

7

8 9

5

6

3

4

10 11 12

19 20 21

13 14 15 16

17 18

22 23 24

ATF TEMPERATURE

SENSOR

TRANSMISSION