Subaru Legacy (2005 year). Manual - part 237

EN(H4SO 2.5)(diag)-233

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

CD:DTC P2103 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT HIGH

DTC DETECTING CONDITION:
Immediately at fault recognition

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO 2.5)(diag)-
40, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO 2.5)(diag)-33, Inspection Mode.>.
WIRING DIAGRAM:
• EC, EK, EH, ER and K4 model

EN-03512

B362

E57

B362

B20

B21

E57

B122

B83

B138

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

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

B135

B:

B136

C:

B137

D:

BATTERY

MAIN RELAY

ELECTRONIC
THROTTLE 
CONTROL RELAY

ELECTRONIC
THROTTLE CONTROL

SBF-7

B135

B:

B137

B136

D:

E1

B20

B83

C:

E

E

E

D6

B35

38

39

20

19

16

15

E2

B21

4

6

1

2

3

5

D4

D5

C35

C16

B1

B4

D1

D2

D3

36

35

37

C29

C18

ECM

5

8

7

6

36

B21

E2

E

B122 : RHD

B138 : LHD

1 2 3 4 5 6

B138 : RHD

B122 : LHD

1 2 3 4
5 6 7 8
9 10 11 12

14

13

15 16

*

: TERMINAL No. RANDOM ARRANGEMENT

1

*

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

2

*

1

*

2

*

1

*

1

*

1

*

2

EN(H4SO 2.5)(diag)-234

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

• KA and KS model

NOTE:
Fuel injection system for KA and KS model is the same as 2.0 L model. Refer to EN(H4SO 2.0) section.

CE:DTC P2109 THROTTLE/PEDAL POSITION SENSOR “A” MINIMUM STOP 

PERFORMANCE

NOTE:
For the diagnostic procedure, refer to DTC P2101. <Ref. to EN(H4SO 2.5)(diag)-224, DTC P2101 THROT-
TLE ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Di-
agnostic Trouble Code (DTC).>

Step

Check

Yes

No

1

CHECK OPTION CODE.

Is the option code EC, EK, EH, 
ER or K4?

Go to step 2.

Refer to EN(H4SO 
2.0) section. <Ref. 
to EN(H4SO 
2.0)(diag)-64, List 
of Diagnostic Trou-
ble Code (DTC).>

NOTE:
Fuel injection sys-
tem for KA and KS
model is the same
as 2.0 L model.

2

CHECK ELECTRONIC THROTTLE CON-
TROL RELAY.
1) Turn the ignition switch to OFF.
2) Remove the electronic throttle control relay.
3) Measure the resistance between electronic 
throttle control relay terminals.

Terminals

No. 7 — No. 8:

Is the resistance more than 1 
M

Ω?

Go to step 3.

Replace the elec-
tronic throttle con-
trol relay.

3

CHECK POWER SUPPLY SHORT CIRCUIT 
OF ELECTRONIC THROTTLE CONTROL 
RELAY.
1) Turn the ignition switch to ON.
2) Measure the voltage between electronic 
throttle control relay connector and chassis 
ground.

Connector & terminal

(B362) No. 7 (+) — Chassis ground (

−

):

Is the voltage more than 5 V?

Go to step 4.

Repair the power 
supply short cir-
cuit of harness 
between ECM and 
electronic throttle 
control relay.

4

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL RE-
LAY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between ECM con-
nector and chassis ground.

Connector & terminal

(B135) No. 35 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Repair the poor 
contact in ECM 
connector. 
Replace the ECM 
if defective. <Ref. 
to FU(H4SO 2.5)-
37, Engine Con-
trol Module 
(ECM).>

Repair the ground 
short circuit of har-
ness between 
ECM and elec-
tronic throttle con-
trol relay.

EN(H4SO 2.5)(diag)-235

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

CF:DTC P2122 THROTTLE/PEDAL POSITION SENSOR/SWITCH “D” CIRCUIT 

LOW INPUT

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

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO 2.5)(diag)-
40, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO 2.5)(diag)-33, Inspection Mode.>.
WIRING DIAGRAM:
• EC, EK, EH, ER and K4 model

• KA and KS model

NOTE:
Fuel injection system for KA and KS model is the same as 2.0 L model. Refer to EN(H4SO 2.0) section.

EN-03468

B315

ACCELERATOR

PEDAL

POSITION

SENSOR

B138

1 2 3 4
5 6 7 8

MAIN

SUB

B21

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

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

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

B:

C:

D:

B122

B83

1 2 3 4 5 6

E

C:

ECM

B136

B137

D:

B83

B315

3

5

4

1

2

6

C15

C17

C34

C16

C28

C35

D1

D2

B21

E2

B1

B138

B122

D3

B: B135

B4

37

36

35

B138

B122

LHD

LHD

RHD

RHD

RHD

LHD

RHD

LHD

*

*

1

1

*

2

*

2

*

2

*

2

*

1

*

1

*

1

*

1

*

: TERMINAL No. RANDOM ARRANGEMENT

1

*

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

2

EN(H4SO 2.5)(diag)-236

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK OPTION CODE.

Is the option code EC, EK, EH, 
ER or K4?

Go to step 2.

Refer to EN(H4SO 
2.0) section. <Ref. 
to EN(H4SO 
2.0)(diag)-64, List 
of Diagnostic Trou-
ble Code (DTC).>

NOTE:
Fuel injection sys-
tem for KA and KS
model is the same
as 2.0 L model.

2

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

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.5)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage more than 0.4 V? Go to step 3.

Go to step 4.

3

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.

4

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. 17 — (B315) No. 5:
(B136) No. 15 — (B315) No. 3:

Is the resistance less than 1 
Ω?

Go to step 5.

Repair the open 
circuit of harness 
connector.

5

CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR.
Measure the resistance between ECM connec-
tor and chassis ground.

Connector & terminal

(B136) No. 17 — Chassis ground:
(B136) No. 15 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 6.

Repair the chas-
sis short circuit of 
harness.

6

CHECK POWER SUPPLY OF ACCELERA-
TOR 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 engine 
ground.

Connector & terminal

(B315) No. 3 (+) — 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 2.5)-
37, Engine Con-
trol Module 
(ECM).>

7

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

Terminals

No. 3 — No. 4:

Is the resistance 1.2 — 4.8 
k

Ω?

Go to step 8.

Replace the accel-
erator pedal posi-
tion sensor.