Subaru Legacy IV (2008 year). Manual - part 757

5AT(diag)-43

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

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
• Does not shift to 5th.
WIRING DIAGRAM:

AT-04349

AT1

1 2 3

1 2 3 4
5 6 7 8

B11

B12

1 2

5

6 7

8

13

14 15

16

9 10

11 12

3 4

17 18

19 20

B54

26

7

B12

T3

B11

T4

TCM

16

2

27

AT1

B54

16

10 11 12 13 14 15

25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

5

6

27

26

33 34 35

7

2

1

3

TURBINE SPEED SENSOR 1

5AT(diag)-44

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK TCM I/O SIGNAL.
Check the power supply and ground I/O signals.
<Ref. to 5AT(diag)-14, ELECTRICAL SPECIFI-
CATION, Transmission Control Module (TCM) I/
O Signal.>

Is TCM I/O signal OK?

Go to step 2.

Repair the open or 
short circuit for 
power supply and 
ground.

2

CHECK TCM AND TRANSMISSION HAR-
NESS CONNECTOR.
1) Disconnect the connectors from TCM and 
transmission.
2) Measure the resistance of harness between 
TCM connector and transmission connector.

Connector & terminal

(B54) No. 16 — (B11) No. 2:
(B54) No. 26 — (B12) No. 7:
(B54) No. 27 — (B11) No. 7:

Is the resistance less than 1 

:? Go to step 3.

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

3

CHECK TCM AND TRANSMISSION HAR-
NESS CONNECTOR.
Measure the resistance of harness between 
TCM connector and chassis ground.

Connector & terminal

(B54) No. 16 — Chassis ground:
(B54) No. 26 — Chassis ground:
(B54) No. 27 — Chassis ground:

Is the resistance less than 1 M

:? Go to step 4.

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

4

CHECK TCM POWER SUPPLY OUTPUT.
1) Connect the connector to the TCM. (Trans-
mission connector is disconnected)
2) Turn the ignition switch to ON. (engine OFF)
3) Measure the voltage between transmission 
connector and chassis ground.

Connector & terminal

(B11) No. 7 (+) — Chassis ground (–):

Is the voltage 10 — 13 V?

Go to step 5.

Replace the TCM. 
<Ref. to 5AT-60, 
Transmission Con-
trol Module 
(TCM).>

5

CHECK INPUT CIRCUIT OF TCM TURBINE 
SPEED SENSOR.
Measure the voltage between TCM connector 
terminals.

Connector & terminal

(B12) No. 7 (+) — (B11) No. 2 (–):

Is the voltage 4 — 6 V?

Go to step 6.

Replace the TCM. 
<Ref. to 5AT-60, 
Transmission Con-
trol Module 
(TCM).>

6

CHECK HARNESS ASSEMBLY (TURBINE 
SPEED SENSOR GROUND).
Check the installing condition of ground con-
necting harness of harness assembly (used for 
both of turbine speed sensor 1, rear vehicle 
speed sensor).

Is the ground connecting har-
ness installed securely to the 
transmission body? Is there 
any serious damage in the har-
ness and terminal?

Go to step 7.

When poor instal-
lation of ground 
occurs, install it 
securely. Replace 
the transmission 
assembly if the 
harness or termi-
nal is damaged. 
<Ref. to 5AT-39, 
Automatic Trans-
mission Assem-
bly.>

5AT(diag)-45

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

7

CHECK HARNESS ASSEMBLY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion.
3) Disconnect the connector from turbine 
speed sensor 1.
4) Measure the resistance between transmis-
sion connector and turbine speed sensor 1 con-
nector.

Connector & terminal

(T3) No. 7 — (AT1) No. 2:
(T4) No. 7 — (AT1) No. 3:
(T4) No. 2 — (AT1) No. 1:
(AT1) No. 1 — Chassis ground:

Is the resistance less than 1 

:? Go to step 8.

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

8

CHECK HARNESS ASSEMBLY.
Measure the resistance between transmission 
connector and chassis ground.

Connector & terminal

(T3) No. 7 — Chassis ground:
(T4) No. 7 — Chassis ground:
(T4) No. 2 — Chassis ground:

Is the resistance 1 M

: or 

more?

Go to step 9.

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

9

CHECK INPUT SIGNAL FOR TCM USING 
SUBARU SELECT MONITOR.
1) Connect all connectors.
2) Lift up the vehicle.

NOTE:
Raise all wheels off the floor.
3) Start the engine, and set the vehicle in 4th 
speed driving condition of manual mode.

NOTE:
Turbine speed sensor 1 signal can be mea-
sured only on 4th speed.
4) Read the current data of turbine speed sen-
sor 1 using the Subaru Select Monitor. <Ref. to 
5AT(diag)-18, READ CURRENT DATA, OPER-
ATION, Subaru Select Monitor.>

NOTE:
The speed difference between front and rear
wheels may illuminate the ABS warning light,
but this does not indicate a malfunction. When
AT control diagnosis is finished, perform the
ABS or VDC clear memory of on-board diag-
nostics system. <Ref. to ABS(diag)-20, Clear
Memory Mode.> <Ref. to VDC(diag)-23, Clear
Memory Mode.>

Does the value of the turbine 
speed sensor 1 change 
depending on the acceleration, 
deceleration and shifting range 
of the vehicle?

Even if the AT OIL 
TEMP light blinks, 
the system is in 
normal condition. 
A temporary poor 
contact of connec-
tor or harness may 
be the cause. 
Repair the poor 
contact of harness 
between ATF tem-
perature sensor 
and transmission 
connector.

Replace the tur-
bine speed sensor 
1. <Ref. to 5AT-56, 
Turbine Speed 
Sensor 1.>

Step

Check

Yes

No

5AT(diag)-46

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

E: DTC P0719 BRAKE SWITCH CIRCUIT LOW

DTC DETECTING CONDITION:
Stop light switch malfunction, open input signal circuit
TROUBLE SYMPTOM:
Brake down control does not operate at S# mode.
WIRING DIAGRAM:

B280

B:

B281

C:

C23

B20

B30

B159

2

1

3 4
8 9

7

6

5

B280

8

7

6

5

4

3

2

1

22

23

21

20

19

16

15

14

13

12

11

10

9

17

30

18

29

28

27

26

25

24

B281

8

7

6

5

4

3

2

1

21

22

20

19

16

15

14

13

12

11

10

9

17 18

28

27

26

25

24

23

21

20

B55

C:

B:

B65

1

2

3

4

TCM

9

5

B65

B225

7.5A

4

3

AT-04350

B55

5

6

7

2

1

3

4

29

10 11 12 13 14 15

25

24

16

30

9

8

17 18 19

20
28

21 22 23

32

31

26 27

33

34 35

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

B365

B365

1

*

2

*

1

*

2

*

SBF-2

E

FUSE
(RELAY BLOCK)

3

2

B225

13
14

15 16

17

27

24

25
26

20

21
22

23

29
30

31

28

32

35

33
34

37
38

39

36

40

8

9

10

11 12

1

2

5

3

4

7

6

19

18

RELAY BLOCK

BODY INTEGRATED UNIT

FUSE & RELAY  
BOX (F/B)

B159

STOP LIGHT  
SWITCH

B

A

TTER

Y

MAIN SBF

No.8

 :

 :

1

*

2

*

TERMINAL No. OPTIONAL 
ARRANGEMENT
AMONG 1, 2 ,3,11,12 AND 13

TERMINAL No. OPTIONAL  
ARRANGEMENT
AMONG 8, 9, 10, 18, 19 AND 20

CAN
JOINT
CONNECTOR