Subaru Legacy III (2000-2003 year). Service manual — part 510

EN(H4DOSTC)-210

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

BB:DTC P1239 — EXHAUST CONTROL VALVE SOLENOID CIRCUIT LOW

(NEGATIVE PRESSURE) —

• 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)-211

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. 3 (+) — 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 SOLENOID VALVE (NEG-
ATIVE PRESSURE) AND ECM CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from exhaust

valve control solenoid valve (negative pres-
sure) and ECM.

3) Measure the resistance of harness

between exhaust valve control solenoid
valve (negative pressure) connector and
engine ground.

Connector & terminal

(B136) No. 3 — Engine ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Repair the ground
short circuit in har-
ness between
ECM and exhaust
valve control sole-
noid valve (nega-
tive pressure)
connector.

Go to step 3.

3

CHECK HARNESS BETWEEN EXHAUST
VALVE CONTROL SOLENOID VALVE (NEG-
ATIVE PRESSURE) AND ECM CONNEC-
TOR.
Measure the resistance of harness between
ECM and exhaust valve control solenoid valve
(negative pressure) of harness connector.

Connector & terminal

(B136) No. 3 — (B220) No. 6:

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 solenoid valve
(negative pres-
sure) connector.

4

CHECK EXHAUST VALVE CONTROL SOLE-
NOID VALVE. (NEGATIVE PRESSURE)
Measure the resistance between exhaust
valve control solenoid valve (negative pres-
sure) terminals.

Terminals

No. 5 — No. 6:

Is the measured value within the specified
value?

30 — 34

Ω

Go to step 5.

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

EN(H4DOSTC)-212

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

5

CHECK POWER SUPPLY TO EXHAUST
VALVE CONTROL SOLENOID VALVE (NEG-
ATIVE PRESSURE).
1) Turn the ignition switch to ON.
2) Measure the voltage between exhaust

valve control solenoid valve (negative pres-
sure) and engine ground.

Connector & terminal

(B220) No. 5 (+) — 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 sole-
noid valve (nega-
tive pressure)
connector.

6

CHECK POOR CONTACT.
Check poor contact in exhaust valve control
solenoid valve (negative pressure) and ECM
connectors.
Are there poor contact in exhaust valve control
solenoid valve (negative pressure) and ECM
connectors?

There are poor contacts.

Repair the poor
contact in exhaust
valve control sole-
noid valve (nega-
tive pressure) 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)-213

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

MEMO: