Subaru Legacy III (2000-2003 year). Service manual — part 513

EN(H4DOSTC)-222

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

6

CHECK POOR CONTACT.
Check poor contact in relief valve control sole-
noid valve 1 and ECM connectors.
Are there poor contact in relief valve control
solenoid valve 1 and ECM connectors?

There are poor contacts.

Repair the poor
contact in relief
valve control sole-
noid valve 1 and
ECM connectors.

Contact SUBARU
distributor service.

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

Step

Value

Yes

No

EN(H4DOSTC)-223

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

MEMO:

EN(H4DOSTC)-224

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

BG:DTC P1248 — RELIEF VALVE CONTROL SOLENOID VALVE 1 CIRCUIT

HIGH —

• 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)-225

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

(B136) No. 12 (+) — 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 RELIEF
VALVE CONTROL SOLENOID VALVE 1 AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from relief valve

control solenoid valve 1.

3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and

chassis ground.

Connector & terminal

(B136) No. 12 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Repair the battery
short circuit in har-
ness between
ECM and relief
valve control sole-
noid valve 1 con-
nector. After
repair, replace the
ECM. <Ref. to
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

Go to step 4.

4

CHECK RELIEF VALVE CONTROL SOLE-
NOID VALVE 1.
1) Turn the ignition switch to OFF.
2) Measure the resistance between relief

valve control solenoid valve 1 terminals.

Terminals

No. 3 — No. 4:

Is the measured value less than the speci-
fied value?

1

Ω

Replace the relief
valve control sole-
noid valve 1 <Ref.
to IN(H4DOSTC)-
19, Solenoid Box
Assembly.> and
replace ECM.
<Ref. to
FU(H4DOSTC)-
40, Engine Con-
trol Module.>

Go to step 5.

5

CHECK POOR CONTACT.
Check poor contact in ECM and relief valve
control solenoid valve 1 connetors.
Are there poor contact in ECM and relief valve
control solenoid valve 1 connetors?

There are poor contacts.

Repair the poor
contact in ECM
connector.

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