Subaru Legacy (2005 year). Manual — part 156

EN(H4SO 2.0)(diag)-213

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BZ: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

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4SO 2.0)(diag)-
38, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO 2.0)(diag)-32, PRO-
CEDURE, Inspection Mode.>.

EN(H4SO 2.0)(diag)-214

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

WIRING DIAGRAM:

EN-03508

SBF-7

B134

A:

B137

B136

D:

B362

E1

B20

C:

E

E

E

D6

D9

38

39

20

19

16

15

E2

B21

E78

2

5

D4

D5

D2

C17

C6

A2

C2

C5

C1

C30

36

35

37

D24

D23

ECM

5

7

8

6

B362

B20

B21

E78

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

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

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

B136

C:

B137

D:

BATTERY

MAIN RELAY

ELECTRONIC
THROTTLE
CONTROL RELAY

ELECTRONIC
THROTTLE CONTROL

D7

D1

D3

C18

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

A:

1

3

4 5 6

2

B83

:LHD

B138 :RHD

B83

:LHD

B138 :RHD

B83

B138

*

1

: TERMINAL No.
RANDOM ARRANGEMENT
AMONG 3,4,7, AND 8

*

2

: TERMINAL No.
RANDOM ARRANGEMENT
AMONG 1,2,5, AND 6

*

3

LHD : 4
RHD : 6

*

4

LHD : 6
RHD : 4

*

5

LHD : 3
RHD : 1

*

6

LHD : 1
RHD : 3

*

1

*

1

*

3

*

4

*

5

*

6

*

2

*

2

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

14

13

15 16

EN(H4SO 2.0)(diag)-215

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK SENSOR OUTPUT.
1) Turn the ignition switch to ON.
2) Read the data of main throttle sensor signal
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.0)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage more than 0.4 V? Go to step 2.

Go to step 4.

2

CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.0)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage more than 0.8 V? Go to step 3.

Go to step 4.

3

CHECK POOR CONTACT.
Check poor contact in connector between
ECM and electronic throttle control.

Is there poor contact?

Repair the poor
contact.

Go to step 14.

4

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

Connector & terminal

(B137) No. 23 — (E78) No. 5:
(B137) No. 24 — (E78) No. 2:
LHD model

(B136) No. 17 — (E78) No. 4:

RHD model

(B136) No. 17 — (E78) No. 6:

Is the resistance less than 1
Ω?

Go to step 5.

Repair the open
circuit of harness
connector.

5

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
Measure the resistance between ECM connec-
tor and chassis ground.

Connector & terminal

(B137) No. 23 — Chassis ground:
(B137) No. 24 — Chassis ground:
(B136) No. 17 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 6.

Repair the ground
short circuit of har-
ness.

6

CHECK SENSOR POWER SUPPLY.
1) Connect the ECM connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic
throttle control connector and engine ground.

Connector & terminal

LHD model

(E78) No. 4 (+) — Engine ground (

−

):

RHD model

(E78) No. 6 (+) — Engine ground (

−

):

Is the voltage 4.5 — 5.5 V?

Go to step 7.

Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.0)-
34, Engine Con-
trol Module
(ECM).>

EN(H4SO 2.0)(diag)-216

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

7

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

Connector & terminal

(E78) No. 5 — Engine ground:
(E78) No. 2 — Engine ground:

Is the resistance more than 10
Ω?

Go to step 8.

Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.0)-
34, Engine Con-
trol Module
(ECM).>

8

CHECK SENSOR OUTPUT.
1) Connect all the connectors.
2) Turn the ignition switch to ON.
3) Read the data of main throttle sensor signal
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.0)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage less than 4.63
V?

Go to step 9.

Go to step 11.

9

CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.0)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage less than 4.73
V?

Go to step 10.

Go to step 11.

10

CHECK POOR CONTACT.
Check poor contact in connector between
ECM and electronic throttle control.

Is there poor contact?

Repair the poor
contact.

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

11

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

Connector & terminal

(B137) No. 23 — (E78) No. 5:
(B137) No. 24 — (E78) No. 2:
LHD model

(B136) No. 17 — (E78) No. 4:

RHD model

(B136) No. 17 — (E78) No. 6:

Is the resistance less than 1
Ω?

Go to step 12.

Repair the open
circuit of harness
connector.

12

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

Connector & terminal

LHD model

(E78) No. 1 — Engine ground:

RHD model

(E78) No. 3 — Engine ground:

Is the resistance less than 5
Ω?

Go to step 13.

Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.0)-
34, Engine Con-
trol Module
(ECM).>

Step

Check

Yes

No