Subaru Legacy III (2000-2003 year). Manual - part 488

EN(H4DOSTC)-122

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

S: DTC P0246 — TURBO/SUPER CHARGERWASTEGATESOLENOID “A” HIGH 

—

• TROUBLE SYMPTOM:

• Erroneous idling

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOSTC)-35, 
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOSTC)-33, Inspection 
Mode.> .
• WIRING DIAGRAM:

EN-00938

MAIN  RELAY

B47

1

2

3

5

4

6

BATTERY

E

B47

B137

F81

F44

B137

F81

       WASTEGATE
CONTROL  SOLENOID
            VALVE

ECM

24

1

2

SBF-5

3

4

1

2

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

B62

F45

B62

B61

F44

1

5

21

9

32

1 2 3 4

5 6

10 11 12 13 14 15

7

16

23

30

19 20

22

26 27 28 29

8

17

24

31

18

25

1 2

3

4 5 6 7 8

EN(H4DOSTC)-123

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

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

(B137) No. 24 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

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?

There is poor contact.

Repair the poor 
contact in ECM 
connector.

Replace the ECM.  
<Ref. to 
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

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

(B137) No. 24 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Repair the battery 
short circuit in har-
ness between 
ECM and waste-
gate control sole-
noid valve 
connector. After 
repair, replace the 
ECM.  <Ref. to 
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

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 measured value less than the speci-
fied value?

1 

Ω

Replace the 
wastegate control 
solenoid valve  
<Ref. to 
IN(H4DOSTC)-21, 
Wastegate Con-
trol Solenoid 
Valve.> and ECM  
<Ref. to 
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

Go to step 5.

5

CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?

There is poor contact.

Repair the poor 
contact in ECM 
connector.

Replace the ECM.  
<Ref. to 
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

EN(H4DOSTC)-124

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

T: DTC P0249 — TURBO/SUPER CHARGERWASTEGATESOLENOID “B” LOW 

—

• TROUBLE SYMPTOM:

• Poor driving performance

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOSTC)-35, 
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOSTC)-33, Inspection 
Mode.> .
• WIRING DIAGRAM:

EN-00939

B220

B47

E

BATTERY

MAIN RELAY

3

B136

ECM

SBF-5

5

2
1

4

6

B47

3

4

1

2

5

6

B220

SOLENOID 
BOX ASSY

1

2

3

4

5

6

7

8

9

10

11

12

(A)

(B)

(C)

(D)

(E)

(F)

(A): RELIEF VALVE SOLENOID 2
(B): RELIEF VALVE SOLENOID 1
(C): EXHAUST VALVE CONTROL SOLENOID VALVE
       (NEGATIVE PRESSURE)
(D): EXHAUST VALVE CONTROL SOLENOID VALVE
       (POSITIVE PRESSURE)
(E): INTAKE AIR CONTROL SOLENOID VALVE
(F): EXHAUST VALVE CONTROL DUTY SOLENOID VALVE

C:

B137

D:

C11

C12

C3

C1

D22

D11

1 2 3 4
5 6 7 8
9 10 11 12

B136

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

B137

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

EN(H4DOSTC)-125

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK INPUT SIGNAL TO ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and 

chassis ground.

Connector & terminal

(B137) No. 11 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Even if MI lights 
up, the circuit has 
returned to a nor-
mal condition at 
this time. Contact 
SUBARU distribu-
tor service.

NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.

Go to step 2.

2

CHECK HARNESS BETWEEN EXHAUST 
VALVE CONTROL DUTY SOLENOID VALVE 
AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from exhaust 

valve control duty solenoid valve and ECM.

3) Measure the resistance of harness 

between exhaust valve control duty sole-
noid valve connector and engine ground.

Connector & terminal

(B220) No. 12 — Engine ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 3.

Repair the ground 
short circuit in har-
ness between 
ECM and exhaust 
valve control duty 
solenoid valve 
connector.

3

CHECK HARNESS BETWEEN EXHAUST 
VALVE CONTROL DUTY SOLENOID VALVE 
AND ECM CONNECTOR.
Measure the resistance of harness between 
ECM and exhaust valve control duty solenoid 
valve of harness connector.

Connector & terminal

(B137) No. 11 — (B220) No. 12:

Is the measured value less than the specified 
value?

1 

Ω

Go to step 4.

Repair the open 
circuit in harness 
between ECM and 
exhaust valve con-
trol duty solenoid 
valve connector.

4

CHECK EXHAUST VALVE CONTROL DUTY 
SOLENOID VALVE.
Measure the resistance between purge control 
solenoid valve terminals.

Terminals

No. 11 — No. 12:

Is the measured value within the specified 
value?

17 — 21 

Ω

Go to step 5.

Replace the 
exhaust valve con-
trol duty solenoid 
valve.  <Ref. to 
IN(H4DOSTC)-19, 
Solenoid Box 
Assembly.>

5

CHECK POWER SUPPLY TO EXHAUST 
VALVE CONTROL DUTY SOLENOID VALVE.
1) Turn the ignition switch to ON.
2) Measure the voltage between exhaust 

valve control duty solenoid valve and 
engine ground.

Connector & terminal

(B220) No. 11 (+) — Engine ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Go to step 6.

Repair the open 
circuit in harness 
between main 
relay and exhaust 
valve control duty 
solenoid valve 
connector.