Subaru Legacy (2005 year). Manual - part 564

4AT(diag)-93

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK ENGINE GROUND TERMINALS.

Have engine ground terminals 
been tightened securely?

Go to step 2.

Tighten the engine 
ground terminals.

2

CHECK GROUND CIRCUIT FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness 
between ECM and engine ground.

Connector & terminal
2.0 L model and 2.5 L KS, KA model

(B134) No. 2 — Engine ground:
(B134) No. 7 — Engine ground:
(B135) No. 5 — Engine ground:
(B135) No. 6 — Engine ground:
(B136) No. 1 — Engine ground:
(B136) No. 2 — Engine ground:
(B136) No. 5 — Engine ground:
(B136) No. 6 — Engine ground:
(B137) No. 1 — Engine ground:

2.5 L EC, EK, K4 model

(B134) No. 7 — Engine ground:
(B134) No. 6 — Engine ground:
(B135) No. 1 — Engine ground:
(B135) No. 4 — Engine ground:
(B135) No. 12 — Engine ground:
(B137) No. 1 — Engine ground:
(B137) No. 2 — Engine ground:
(B137) No. 3 — Engine ground:
(B137) No. 7 — Engine ground:

Is the resistance less than 5 
Ω?

Go to step 3.

Repair the open 
circuit of harness 
between ECM 
connector and 
engine grounding 
terminal.

3

CHECK ACCELERATOR PEDAL POSITION 
SENSOR.
1) Disconnect the connectors from accelerator 
pedal position sensor.
2) Measure the resistance between accelera-
tor pedal position sensor connector recepta-
cle’s terminals.

Connector & terminal

No. 1 — No. 6:

Is the resistance 0.75 — 3.15 
k

Ω?

Go to step 4.

Replace the accel-
erator pedal posi-
tion sensor.

4

CHECK ACCELERATOR PEDAL POSITION 
SENSOR.
Measure the resistance between accelerator 
pedal position sensor connector receptacle’s 
terminals.

Connector & terminal

No. 6 — No. 2:

Is the resistance 0.15 — 1.05 
k

Ω?

Go to step 5.

Replace the accel-
erator pedal posi-
tion sensor.

5

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND ACCELERATOR PEDAL POSI-
TION SENSOR.
1) Disconnect the connector from TCM.
2) Measure the resistance of harness 
between TCM and accelerator pedal position 
sensor connector.

Connector & terminal

(B54) No. 19 — (B315) No. 2:

Is the resistance less than 1 
Ω?

Go to step 6.

Repair the open 
circuit of harness 
between TCM and 
accelerator pedal 
position sensor 
connector, and 
poor contact in 
coupling connec-
tor.

6

CHECK HARNESS CONNECTOR BETWEEN 
TCM AND ACCELERATOR PEDAL POSI-
TION SENSOR.
Measure the resistance of harness between 
TCM connector and chassis ground.

Connector & terminal

(B54) No. 19 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 7.

Repair the short 
circuit of harness 
between TCM and 
accelerator pedal 
position sensor 
connector.

4AT(diag)-94

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

7

CHECK HARNESS CONNECTOR BETWEEN 
ECM AND ACCELERATOR PEDAL POSI-
TION SENSOR.
1) Remove the connector from ECM.
2) Measure the resistance of harness 
between accelerator pedal position sensor 
connector and chassis ground.

Connector & terminal

(B315) No. 6 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 8.

Repair the short 
circuit of harness 
between ECM and 
accelerator pedal 
position sensor.

8

CHECK INPUT SIGNAL FOR TCM USING 
SUBARU SELECT MONITOR.
1) Connect the connectors to TCM, accelera-
tor pedal position sensor and ECM.
2) Connect the Subaru Select Monitor to data 
link connector.
3) Turn the ignition switch to ON (engine 
OFF).
4) Turn the Subaru Select Monitor power 
switch to ON.
5) Fully close the throttle.
6) Read the data of accelerator pedal position 
sensor using Subaru Select Monitor.
• Accelerator pedal position sensor input sig-
nal is indicated.

Is the voltage more than 0.2 V? 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 accelerator 
pedal position sen-
sor circuit.

Go to step 9.

9

CHECK POOR CONTACT.

Is there poor contact in accel-
erator pedal position sensor 
circuit?

Repair the poor 
contact.

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

Step

Check

Yes

No

4AT(diag)-95

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Y: DTC P1709 THROTTLE POSITION SENSOR CIRCUIT HIGH INPUT

DTC DETECTING CONDITION:
The input signal circuit of accelerator pedal position sensor is shorted.
TROUBLE SYMPTOM:
• Shift point is too high or too low.
• Excessive shift shock
• Tight corner braking phenomenon is occurred.
WIRING DIAGRAM:
• 2.0 L LHD and 2.5 L KS model

AT-01894

2 3 4

1

5 6

B54

B21

1 2

7

8 9

5

6

3

4

10 11 12

19 20 21

13 14 15 16

17 18

22 23 24

B315

B83

B21

B134

B83

B54

TCM

A:

B135

B:

B136

C:

ECM

B137

D:

E2

52

37

35

34

1

2

6

19

D30

C17

C18

B5

B6

C6

C1

A2

C2

A7

D1

E

E

1

2

JOINT CONNECTOR

ACCELERATOR PEDAL POSITION SENSOR

B315

C5

36

B137

5

6

7

8

2

1

9

4

3

10

22 23

11 12 13 14 15

24 25

26

16 17

18 19 20 21

27

28 29

30 31

B134

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17

18 19 20 21

33 34

29

32

30 31

B136

5

6

7 8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16

17 18 19 20 21

33 34

29

32

30

31

35

B135

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17 18 19

20 21

29 30 31

32 33

34 35

1 2 3 4
5 6 7 8

1 2 3 4

12 13 14 15

5 6 7 8

16 17 18 19

9 10 11

20 21 22

23 24 25 26 27 28 29 30 31 32 33

35

34

37

36

39

38

41

40

43

42

44

45

47

46

49

48

51

50

53

52

54

A:

B:

C:

D:

D18

10

4AT(diag)-96

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

• 2.5 L EC, K4 model

AT-01494

2 3 4

1

5 6

B54

B21

1 2

7

8 9

5

6

3

4

10 11 12

19 20 21

13 14 15 16

17 18

22 23 24

B315

B83

B21

B134

B83

B54

TCM

A:

B135

B:

B136

C:

ECM

B137

D:

E2

37

52

47

35

36

1

2

6

10

19

C28

C16

C35

A6

A7

D7

B12

B4

D1

D2

B1

E

E

1

2

JOINT CONNECTOR

ACCELERATOR PEDAL POSITION SENSOR

B315

5

1

6

D3

34

B137

5

6

7

8

2

1

9

4

3

10

22 23

11 12 13 14 15

24 25

26

16 17

18 19 20 21

27

28 29

30 31

B134

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17

18 19 20 21

33 34

29

32

30 31

B136

5

6

7 8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16

17 18 19 20 21

33 34

29

32

30

31

35

B135

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17 18 19

20 21

29 30 31

32 33

34 35

1 2 3 4
5 6 7 8

1 2 3 4

12 13 14 15

5 6 7 8

16 17 18 19

9 10 11

20 21 22

23 24 25 26 27 28 29 30 31 32 33

35

34

37

36

39

38

41

40

43

42

44

45

47

46

49

48

51

50

53

52

54

A:

B:

C:

D:

B122

B122

JOINT
CONNECTOR