Subaru Legacy IV (2008 year). Service manual — part 362

EN(H4DOTC)(diag)-269

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CU:DTC P1443 VENT CONTROL SOLENOID VALVE FUNCTION PROBLEM

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-179, DTC P1443 VENT CONTROL SOLENOID
VALVE FUNCTION PROBLEM, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
Improper fuel supply

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
52, OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-43, PRO-
CEDURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-05679

SBF-7

E4

B47

E

5
3

6
4

2
1

2

1

C17

C28

D29

C7

R15

R213

R68

R144

R1

B97

14

15

2

2

1

1

7

1

5

E52

2

1

E52

R144

E4

B47

R67

B97

R213

R68

1 2

3

4

1

2

5

6

B21

1 2

1 2

3

4 5 6 7 8

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

1

2

3 4 5 6

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

R46

R67

6

B21

E2

11

48

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:

B137

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

D:

B136

C:

B137

D:

44

MAIN RELAY

ECM

BATTERY

DRAIN VALVE

PRESSURE

CONTROL

SOLENOID VALVE

PURGE CONTROL

SOLENOID VALVE 1

PURGE CONTROL

SOLENOID VALVE 2

EN(H4DOTC)(diag)-270

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check the appro-
priate DTC using
the “List of Diag-
nostic Trouble
Code (DTC)”.
<Ref. to
EN(H4DOTC)(diag)
-81, List of Diag-
nostic Trouble
Code (DTC).>

Go to step 2.

2

CHECK DRAIN HOSE.
Check the drain hose for clogging.

Is there clogging in the drain
hose?

Replace the drain
hose.

Go to step 3.

3

CHECK DRAIN VALVE OPERATION.
1) Turn the ignition switch to OFF.
2) Connect the delivery (test) mode connector
at the lower portion of instrument panel (on the
driver’s side).
3) Turn the ignition switch to ON.
4) Operate the drain valve.

NOTE:
Drain valve can be operated using the Subaru
Select Monitor. For the procedures, refer to
“Compulsory Valve Operation Check Mode”.
<Ref. to EN(H4DOTC)(diag)-53, Compulsory
Valve Operation Check Mode.>

Does the drain valve operate?

Repair the poor
contact of ECM
connector.

Replace the drain
valve. <Ref. to
EC(H4DOTC)-19,
Drain Valve.>

EN(H4DOTC)(diag)-271

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CV:DTC P1491 POSITIVE CRANKCASE VENTILATION (BLOW-BY) FUNCTION

PROBLEM

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-181, DTC P1491 POSITIVE CRANKCASE VENTILA-
TION (BLOW-BY) FUNCTION PROBLEM, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
Improper idling

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
52, OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-43, PRO-
CEDURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-05683

E80

1

2

A30

D6

D26

45

41

B21

E2

B137

D:

B134

A:

D:

A:

B137

B134

B21

E80

1 2

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

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

8

5

6

10 11 12 13 14 15

7

2

1

3

4

16

30

19 20

22

28 29

9

17

18

25

21

23 24

32

31

26 27
33 34

ECM

PCV HOSE

ASSY

EN(H4DOTC)(diag)-272

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK BLOW-BY HOSE.
Check the condition of the blow-by hose.

Is there any disconnection or
crack in blow-by hose?

Repair or replace
the blow-by hose.

Go to step 2.

2

CHECK HARNESS BETWEEN ECM AND
PCV HOSE ASSEMBLY.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM
and PCV hose assembly.
3) Measure the resistance of harness between
ECM and PCV hose assembly.

Connector & terminal

(B134) No. 30 — (E80) No. 2:

Is the resistance less than 1

:? Go to step 3.

Repair the harness
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and PCV
hose assembly
• Poor contact of
coupling connector

3

CHECK HARNESS BETWEEN ECM AND
PCV HOSE ASSEMBLY.
Measure the resistance between PCV hose
assembly and chassis ground.

Connector & terminal

(B134) No. 30 — Chassis ground:

Is the resistance 1 M

: or

more?

Go to step 4.

Repair the ground
short circuit of har-
ness between
ECM and PCV
hose assembly.

4

CHECK GROUND CIRCUIT OF PCV HOSE
ASSEMBLY.
Measure the resistance of harness between
PCV hose assembly and engine ground.

Connector & terminal

(E80) No. 1 — Engine ground:

Is the resistance less than 5

:? Go to step 5.

Repair the open
circuit of harness
between PCV hose
assembly and
engine ground.

5

CHECK THE PCV HOSE ASSEMBLY.
Measure the resistance between the PCV hose
assembly terminals.

Terminals

No. 1 — No. 2:

Is the resistance less than 1

:? Repair the poor

contact in ECM
and PCV hose
assembly connec-
tor.

Replace the PCV
hose assembly.