Subaru Legacy IV (2008 year). Manual - part 589

EN(H6DO)(diag)-329

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

EC:DTC P2102 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT LOW

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-193, DTC P2102 THROTTLE ACTUATOR CONTROL
MOTOR CIRCUIT LOW, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Improper idling
• Poor driving performance
• Engine stalls.

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)-330

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK ELECTRONIC THROTTLE CON-
TROL RELAY.
1) Turn the ignition switch to OFF.
2) Remove the electronic throttle control relay.
3) Connect the battery to terminals No. 5 and 
No. 6 of electronic throttle control relay.
4) Measure the resistance between electronic 
throttle control relay terminals.

Terminals

No. 7 — No. 8:

Is the resistance less than 1 

:? Go to step 2.

Replace the elec-
tronic throttle con-
trol relay. <Ref. to 
EN(H6DO)(diag)-
8, Electrical Com-
ponent Location.>

2

CHECK POWER SUPPLY OF ELECTRONIC 
THROTTLE CONTROL RELAY.
Measure the voltage between electronic throttle 
control relay connector and chassis ground.

Connector & terminal

(B362) No. 7 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step 3.

Repair the open or 
ground short circuit 
of power supply 
circuit.

3

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL RE-
LAY.
1) Disconnect the connectors from ECM.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic 
throttle control relay connector and chassis 
ground.

Connector & terminal

(B362) No. 6 (+) — Chassis ground (–):

Is the voltage 10 V or more?

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

Go to step 4.

4

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL RE-
LAY.
1) Turn the ignition switch to OFF.
2) Measure the resistance between electronic 
throttle control relay connector and chassis 
ground.

Connector & terminal

(B362) No. 6 — Chassis ground:
(B362) No. 8 — Chassis ground:

Is the resistance 1 M

: or 

more?

Go to step 5.

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

5

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL RE-
LAY.
Measure the resistance between ECM and 
electronic throttle control relay connector.

Connector & terminal

(B136) No. 21 — (B362) No. 6:
(B136) No. 1 — (B362) No. 8:

Is the resistance less than 1 

:? Repair the poor 

contact of ECM 
connector.

Repair the open 
circuit of harness 
between ECM and 
electronic throttle 
control relay.

EN(H6DO)(diag)-331

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

ED:DTC P2103 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT HIGH

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-195, DTC P2103 THROTTLE ACTUATOR CONTROL
MOTOR CIRCUIT HIGH, 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.>.
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)-332

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

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

PERFORMANCE

NOTE:
For the diagnostic procedure, refer to DTC P2101. <Ref. to EN(H6DO)(diag)-324, DTC P2101 THROTTLE
ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

Step

Check

Yes

No

1

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 1 M

: or 

more?

Go to step 2.

Replace the elec-
tronic throttle con-
trol relay. <Ref. to 
EN(H6DO)(diag)-
8, Electrical Com-
ponent Location.>

2

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

Connector & terminal

(B362) No. 8 (+) — Chassis ground (–):

Is the voltage 10 V or more?

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

Go to step 3.

3

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

Connector & terminal

(B136) No. 21 — Chassis ground:

Is the resistance 1 M

: or 

more?

Repair the poor 
contact of ECM 
connector.

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