Subaru Legacy IV (2008 year). Manual — part 349

EN(H4DOTC)(diag)-217

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK FUEL FILLER CAP.
1) Turn the ignition switch to OFF.
2) Check the fuel filler cap.

NOTE:
The DTC is stored in memory if fuel filler cap is
or was loose or if the cap chain has caught while
tightening.

Is the fuel filler cap tightened
securely?

Go to step 2.

Tighten fuel filler
cap securely.

2

CHECK FUEL FILLER CAP.

Is the fuel filler cap genuine?

Go to step 3.

Replace with a
genuine fuel filler
cap.

3

CHECK FUEL FILLER PIPE GASKET.

Is there any damage to the seal
between fuel filler cap and fuel
filler pipe?

Repair or replace
the fuel filler cap
and fuel filler pipe.
<Ref. to
FU(H4DOTC)-66,
Fuel Filler Pipe.>

Go to step 4.

4

CHECK DRAIN VALVE.
1) Connect the delivery (test) mode connector.
2) Turn the ignition switch to ON.
3) Operate the drain valve using the Subaru
Select Monitor.

NOTE:
The drain valve can be operated using 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?

Go to step 5.

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

5

CHECK PURGE CONTROL SOLENOID
VALVE.
Operate the purge control solenoid valve using
the Subaru Select Monitor.

NOTE:
Purge control solenoid valve operation can be
executed using Subaru Select Monitor. For the
procedures, refer to “Compulsory Valve Opera-
tion Check Mode”. <Ref. to EN(H4DOTC)(di-
ag)-53, Compulsory Valve Operation Check
Mode.>

Does the purge control sole-
noid valve operate?

Go to step 6.

Replace the purge
control solenoid
valve. <Ref. to
EC(H4DOTC)-9,
Purge Control
Solenoid Valve.>

6

CHECK PRESSURE CONTROL SOLENOID
VALVE.
Operate the pressure control solenoid valve
using the Subaru Select Monitor.

NOTE:
The pressure control solenoid valve operation
can be executed using the Subaru Select Mon-
itor. For the procedures, refer to “Compulsory
Valve Operation Check Mode”. <Ref. to
EN(H4DOTC)(diag)-53, Compulsory Valve Op-
eration Check Mode.>

Does the pressure control sole-
noid valve operate?

Go to step 7.

Replace the pres-
sure control sole-
noid valve. <Ref. to
EC(H4DOTC)-16,
Pressure Control
Solenoid Valve.>

7

CHECK EVAPORATIVE EMISSION CON-
TROL SYSTEM LINE.
1) Turn the ignition switch to OFF.
2) Disconnect the delivery (test) mode connec-
tor.

Is there any hole of more than
1.0 mm (0.04 in) dia. on evapo-
ration line?

Repair or replace
the evaporation
line. <Ref. to
FU(H4DOTC)-80,
Fuel Delivery,
Return and Evapo-
ration Lines.>

Go to step 8.

EN(H4DOTC)(diag)-218

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

8

CHECK CANISTER.

Is the canister damaged or is
there a hole of more than 1.0
mm (0.04 in) dia. in it?

Repair or replace
the canister. <Ref.
to EC(H4DOTC)-7,
Canister.>

Go to step 9.

9

CHECK FUEL TANK.
Remove the fuel tank. <Ref. to FU(H4DOTC)-
59, Fuel Tank.>

Is the fuel tank damaged or is
there any hole of more than 1.0
mm (0.04 in) dia. in it?

Repair or replace
the fuel tank. <Ref.
to FU(H4DOTC)-
59, Fuel Tank.>

Go to step 10.

10

CHECK ANY OTHER MECHANICAL TROU-
BLE IN EVAPORATIVE EMISSION CON-
TROL SYSTEM.

Is there any hole of more than
1.0 mm (0.04 in) dia., crack,
clogging, or disconnections,
bend, misconnection of hoses
or pipes in evaporative emis-
sion control system?

Repair or replace
the hoses or pipes.

Repair the poor
contact of ECM
connector.

Step

Check

Yes

No

EN(H4DOTC)(diag)-219

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BM:DTC P0447 EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL

CIRCUIT OPEN

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-124, DTC P0447 EVAPORATIVE EMISSION CON-
TROL SYSTEM VENT CONTROL CIRCUIT OPEN, Diagnostic Trouble Code (DTC) Detecting Criteria.>

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)-220

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

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

Connector & terminal

(B136) No. 17 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Repair the poor
contact of ECM
connector.

Go to step 2.

2

CHECK HARNESS BETWEEN ECM AND
DRAIN VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM
and drain valve.
3) Measure the resistance between the drain
valve connector and chassis ground.

Connector & terminal

(R144) No. 2 — Chassis ground:

Is the resistance 1 M

: or

more?

Go to step 3.

Repair the ground
short circuit of har-
ness between
ECM and drain
valve connector.

3

CHECK HARNESS BETWEEN ECM AND
DRAIN VALVE.
Measure the resistance of harness between
ECM and drain valve connector.

Connector & terminal

(B136) No. 17 — (R144) No. 2:

Is the resistance less than 1

:? Go to step 4.

Repair the harness
and connector.

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

4

CHECK DRAIN VALVE.
Measure the resistance between drain valve
terminals.

Terminals

No. 1 — No. 2:

Is the resistance between 10 —
100

:?

Go to step 5.

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

5

CHECK POWER SUPPLY TO DRAIN VALVE.
1) Turn the ignition switch to ON.
2) Measure the voltage between drain valve
and chassis ground.

Connector & terminal

(R144) No. 1 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Repair poor con-
tact of the drain
valve connector.

Repair the harness
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
main relay and
drain valve
• Poor contact of
coupling connector
• Poor contact of
main relay connec-
tor