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