Subaru Legacy (2005 year). Manual - part 338

EN(H4DOTC)(diag)-121

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Y: DTC P0245 TURBO/SUPER CHARGER WASTEGATE SOLENOID “A” LOW

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
Erroneous idling

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
37, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)(diag)-30, PROCE-
DURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-03525

B47

1

2

4

6

3

5

E

B47

B134

E64

B134

E64

ECM

32

1

2

SBF-4

3

4

1

2

5

6

1 2

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

MAIN RELAY

BATTERY

       WASTEGATE
CONTROL SOLENOID
            VALVE

B21

E2

40

48

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

EN(H4DOTC)(diag)-122

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B134) No. 32 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Even if the mal-

function indicator 
light illuminates, 
the circuit has 
returned to a nor-
mal condition at 
this time.

Go to step 2.

2

CHECK HARNESS BETWEEN WASTEGATE 
CONTROL SOLENOID VALVE AND ECM 
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from wastegate 
control solenoid valve and ECM.
3) Measure the resistance of harness 
between wastegate control solenoid valve con-
nector and engine ground.

Connector & terminal

(E64) No. 1 — Engine ground:

Is the resistance more than 1 
M

Ω?

Go to step 3.

Repair the ground 
short circuit of har-
ness between 
ECM and waste-
gate control sole-
noid valve 
connector.

3

CHECK HARNESS BETWEEN WASTEGATE 
CONTROL SOLENOID VALVE AND ECM 
CONNECTOR.
Measure the resistance of harness between 
wastegate control solenoid valve of harness 
connector and ECM.

Connector & terminal

(B134) No. 32 — (E64) No. 1:

Is the resistance less than 1 
Ω?

Go to step 4.

Repair the open 
circuit of harness 
between ECM and 
wastegate control 
solenoid valve 
connector.

NOTE:
In this case, repair
the following:
• Open circuit of 
harness between 
ECM and waste-
gate control sole-
noid valve 
connector

4

CHECK WASTEGATE CONTROL SOLE-
NOID VALVE.
1) Remove the wastegate control solenoid 
valve.
2) Measure the resistance between wastegate 
control solenoid valve terminals.

Terminals

No. 1 — No. 2:

Is the resistance 30 — 34 

Ω?

Go to step 5.

Replace the 
wastegate control 
solenoid valve. 
<Ref. to 
FU(H4DOTC)-31, 
Wastegate Con-
trol Solenoid 
Valve.>

5

CHECK POWER SUPPLY TO WASTEGATE 
CONTROL SOLENOID VALVE.
1) Turn the ignition switch to ON.
2) Measure the voltage between wastegate 
control solenoid valve and engine ground.

Connector & terminal

(E64) No. 2 (+) — Engine ground (

−

):

Is the voltage more than 10 V? Go to step 6.

Repair the open 
circuit of harness 
between main 
relay and waste-
gate control sole-
noid valve 
connector.

6

CHECK POOR CONTACT.
Check poor contact in wastegate control sole-
noid valve connector.

Is there poor contact in waste-
gate control solenoid valve 
connector?

Repair the poor 
contact in waste-
gate control sole-
noid valve 
connector.

Replace the ECM. 
<Ref. to 
FU(H4DOTC)-34, 
Engine Control 
Module (ECM).>

EN(H4DOTC)(diag)-123

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Z: DTC P0246 TURBO/SUPER CHARGER WASTEGATE SOLENOID “A” HIGH

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
Erroneous idling

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
37, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)(diag)-30, PROCE-
DURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-03525

B47

1

2

4

6

3

5

E

B47

B134

E64

B134

E64

ECM

32

1

2

SBF-4

3

4

1

2

5

6

1 2

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

MAIN RELAY

BATTERY

       WASTEGATE
CONTROL SOLENOID
            VALVE

B21

E2

40

48

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

EN(H4DOTC)(diag)-124

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B134) No. 32 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 3.

Go to step 2.

2

CHECK POOR CONTACT.
Check poor contact in ECM connector. 

Is there poor contact in ECM 
connector?

Repair the poor 
contact in ECM 
connector.

Replace the ECM. 
<Ref. to 
FU(H4DOTC)-34, 
Engine Control 
Module (ECM).>

3

CHECK HARNESS BETWEEN WASTEGATE 
CONTROL SOLENOID VALVE AND ECM 
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from wastegate 
control solenoid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B134) No. 32 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Repair the battery 

short circuit of har-
ness between 
ECM and waste-
gate control sole-
noid valve 
connector. After 
repair, replace the 
ECM. <Ref. to 
FU(H4DOTC)-34, 
Engine Control 
Module (ECM).>

Go to step 4.

4

CHECK WASTEGATE CONTROL SOLE-
NOID VALVE.
1) Turn the ignition switch to OFF.
2) Measure the resistance between wastegate 
control solenoid valve terminals.

Terminals

No. 1 — No. 2:

Is the resistance less than 1 
Ω?

Replace the 
wastegate control 
solenoid valve and 
ECM. <Ref. to 
FU(H4DOTC)-31, 
Wastegate Con-
trol Solenoid 
Valve.> <Ref. to 
FU(H4DOTC)-34, 
Engine Control 
Module (ECM).>

Go to step 5.

5

CHECK POOR CONTACT.
Check poor contact in ECM connector.

Is there poor contact in ECM 
connector?

Repair the poor 
contact in ECM 
connector.

Replace the ECM. 
<Ref. to 
FU(H4DOTC)-34, 
Engine Control 
Module (ECM).>