Subaru Legacy (2005 year). Service manual — part 358

EN(H4DOTC)(diag)-201

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

8

CHECK ACCELERATOR PEDAL POSITION
SENSOR.
1) Measure the resistance of accelerator
pedal position sensor.

Terminals

No. 2 — No. 6:

2) Check the measured value is within the
specification with the accelerator pedal
depressed.

Is the resistance 0.28 — 1.68
k

Ω?

Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4DOTC)-
34, Engine Con-
trol Module
(ECM).>

Replace the accel-
erator pedal posi-
tion sensor.

Step

Check

Yes

No

EN(H4DOTC)(diag)-202

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BT:DTC P2128 THROTTLE/PEDAL POSITION SENSOR/SWITCH “E” CIRCUIT

HIGH INPUT

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
• Erroneous idling
• Poor driving performance
WIRING DIAGRAM:

EN-03546

B315

B21

E

C:

ECM

B136

B137

D:

C:

B136

B137

D:

B83

B315

*

*

3

5

4

1

2

6

C15

C17

C34

C16

C28

C35

D1

D2

1 2 3 4 5 6

B122

1 2 3 4
5 6 7 8

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

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

MAIN

SUB

ACCELERATOR

PEDAL POSITION

SENSOR

B122

7

4

36

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

B21

E2

B83

*

: TERMINAL No. RANDOM ARRANGEMENT

EN(H4DOTC)(diag)-203

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK ACCELERATOR PEDAL POSITION
SENSOR OUTPUT.
1) Turn the ignition switch to ON.
2) Read the data of sub accelerator pedal
position sensor signal using Subaru Select
Monitor.

NOTE:

• Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-24, Subaru Select Mon-
itor.>

Is the voltage less than 4.8 V? Go to step 2.

Go to step 3.

2

CHECK POOR CONTACT.
Check poor contact in connector between
ECM and accelerator pedal position sensor.

Is there poor contact?

Repair the poor
contact.

Temporary poor
contact occurred,
but it is normal at
present.

3

CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from accelerator
pedal position sensor.
4) Measure the resistance between ECM con-
nector and accelerator pedal position sensor
connector.

Connector & terminal

(B136) No. 35 — (B315) No. 6:

Is the resistance less than 1
Ω?

Go to step 4.

Repair the open
circuit of harness
connector.

4

CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Connect the ECM connector.
2) Measure the resistance between accelera-
tor pedal position sensor connector and chas-
sis ground.

Connector & terminal

(B315) No. 6 — Chassis ground:

Is the resistance less than 5
Ω?

Go to step 5.

Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4DOTC)-
34, Engine Con-
trol Module
(ECM).>

5

CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Connect the ECM connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between accelerator
pedal position sensor connector and chassis
ground.

Connector & terminal

(B315) No. 2 (+) — Chassis ground (

−

):

Is the voltage less than 6 V?

Go to step 6.

Repair the battery
short circuit of har-
ness between
ECM connector
and accelerator
pedal position sen-
sor connector.

6

CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between ECM con-
nector terminals.

Connector & terminal

(B137) No. 28 — (B137) No. 15:
(B137) No. 28 — (B137) No. 16:

Is the resistance more than 1
M

Ω?

Repair the poor
contact in acceler-
ator pedal position
sensor connector.
Replace the accel-
erator pedal posi-
tion sensor if
defective.

Repair the short
circuit to sensor
power supply.

EN(H4DOTC)(diag)-204

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

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

VOLTAGE CORRELATION

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
• Erroneous idling
• Poor driving performance
WIRING DIAGRAM:

EN-03524

SBF-7

B135

B:

B137

B136

D:

B362

B84

B138

B122

E1

B20

E57

C:

B135

B362

B20

B21

E57

B84

B122

B138

B137

B136

E

E

D6

B35

16

15

*

*

*

*

7
3

E2

B21

39

38

19

20

35

36

37

4

6

1

2

3

5

D4

D5

C35

C16

B1

B4

D1

D2

D3

C29

C18

5

8

7

6

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

1 2

7 8

3
4

5
6

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

34 35

36 37 38 39 40 41

48 49

50 51 52 53 54

42 43

44 45

46 47

26 27 28 29 30 31 32 33

1 2 3 4
5 6 7 8

1 2 3 4 5 6

1

2

7

8 9

5

6

3

4

10 11 12

19 20 21

29

30 31

13 14 15 16 17

27

28

18

22 23

24 25

26

1

2

7

8 9

5

6

3

4

10 11 12

19

20 21

29 30 31

13 14 15 16 17

27

28

18

22 23

24 25

26

32 33

34 35

1

2

8 9

5

6

3

4

10 11 12

19 20 21

29 30

31

13 14 15 16

17

27

28

18

22 23 24 25 26

7

32 33 34 35

B:

D:

C:

ECM

BATTERY

MAIN RELAY

ELECTRONIC
THROTTLE
CONTROL RELAY

ELECTRONIC
THROTTLE
CONTROL

*

: TERMINAL No. RANDOM ARRANGEMENT