Subaru Legacy IV (2008 year). Manual - part 592

EN(H6DO)(diag)-341

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

EJ:DTC P2135 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A”/“B” VOLTAGE 

CORRELATION

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-207, DTC P2135 THROTTLE/PEDAL POSITION SEN-
SOR/SWITCH “A”/“B” VOLTAGE CORRELATION, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Improper idling
• Poor driving performance

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

B20

1 2 3 4 5 6

E57

1 2 3 4
5 6 7 8

B122

1 2

7 8

3
4

5
6

B362

36

52

34

35

37

E

E2

B21

E

A5

C21

C1

A29

19

E1

B20

A18

C6

A28

6

4

15

*

*

B122

16

E

38

39

20

D5

D4

A19

D7

D1

A3

D2

D3

3

E57

ELECTRONIC THROTTLE 

CONTROL

2

1

5

B134

B362

5

7

6

A:

B137

B136

D:

C:

ECM

*

: TERMINAL No. OPTIONAL ARRANGEMENT

E

SBF-7

BATTERY

ELECTRONIC 
THROTTLE
CONTROL RELAY

MAIN RELAY

8

6

4

B47

B47

3

4

1

2

5

6

EN-06873

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

B136

C:

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

B137

D:

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

B134

A:

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47

EN(H6DO)(diag)-342

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and 
electronic throttle control.
3) Measure the resistance between ECM and 
chassis ground.

Connector & terminal

(B134) No. 19 — Chassis ground:
(B134) No. 18 — Chassis ground:
(B134) No. 18 — (B136) No. 6:
(B134) No. 28 — Chassis ground:

Is the resistance 1 M

: or 

more?

Go to step 2.

Repair the short 
circuit to ground in 
harness between 
ECM and elec-
tronic throttle con-
trol connector.

2

CHECK SHORT CIRCUIT INSIDE THE ECM.
1) Connect the connector to ECM.
2) Measure the resistance between electronic 
throttle control connector and engine ground.

Connector & terminal

(E57) No. 6 — Engine ground:
(E57) No. 4 — Engine ground:

Is the resistance 1 M

: or 

more?

Go to step 3.

Repair the short 
circuit to ground in 
harness between 
ECM and elec-
tronic throttle con-
trol connector. 
Replace the ECM if 
defective. <Ref. to 
FU(H6DO)-38, 
Engine Control 
Module (ECM).>

3

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Disconnect the connectors from ECM.
2) Measure the resistance of harness between 
ECM and electronic throttle control connector.

Connector & terminal

(B134) No. 18 — (E57) No. 6:
(B134) No. 28 — (E57) No. 4:
(B134) No. 29 — (E57) No. 3:

Is the resistance less than 1 

:? Go to step 4.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and electron-
ic throttle control
connector
• Poor contact of
coupling connector

4

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Connect the connector to ECM.
2) Measure the resistance between electronic 
throttle control connector and engine ground.

Connector & terminal

(E57) No. 3 — Engine ground:

Is the resistance less than 5 

:? Go to step 5.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and engine
ground
• Poor contact in
ECM connector
• Poor contact of
coupling connector

5

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to ON.
2) Measure the voltage between electronic 
throttle control connector and engine ground.

Connector & terminal

(E57) No. 6 (+) — Engine ground (–):
(E57) No. 4 (+) — Engine ground (–):

Is the voltage 4.85 V or more?

Repair the short 
circuit to power in 
the harness 
between ECM and 
electronic throttle 
control connector.

Go to step 6.

EN(H6DO)(diag)-343

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

6

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance between ECM con-
nectors.

Connector & terminal

(B134) No. 19 — (B134) No. 18:
(B134) No. 19 — (B134) No. 28:

Is the resistance 1 M

: or 

more?

Repair poor con-
tact of the elec-
tronic throttle 
control connector. 
Replace the elec-
tronic throttle con-
trol if defective. 
<Ref. to 
FU(H6DO)-13,
Throttle Body.>

Repair the short 
circuit to power in 
the harness 
between ECM and 
electronic throttle 
control connector.

Step

Check

Yes

No

EN(H6DO)(diag)-344

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

EK:DTC P2138 THROTTLE/PEDAL POSITION SENSOR/SWITCH “D”/“E” 

VOLTAGE CORRELATION

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-209, DTC P2138 THROTTLE/PEDAL POSITION SEN-
SOR/SWITCH “D”/“E” VOLTAGE CORRELATION, Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
TROUBLE SYMPTOM:
• Improper idling
• Poor driving performance
WIRING DIAGRAM:

E

C:

ECM

B136

B137

D:

B83

B315

*

*

4

6

5

1

3

2

B21

B23

B29

B22

B31

B30

A3

D2

B21

E2

D1

1 2 3 4
5 6 7 8

B122

B83

D3

A5

C6

B: B135

A: B134

D7

37

35

34

52

36

B122

B315

1 2 3 4 5 6

*

*

*

E

EN-06883

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

B136

C:

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

B137

D:

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

B135

B:

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

B134

A:

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47

ACCELERATOR  

PEDAL 

POSITION

SENSOR

: TERMINAL No. OPTIONAL 
 ARRANGEMENT