Subaru Legacy IV (2008 year). Manual — part 567

EN(H6DO)(diag)-241

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CE:DTC P0447 EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL

CIRCUIT OPEN

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-124, DTC P0447 EVAPORATIVE EMISSION CONTROL
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(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

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

SBF-7

R144

R67

R213

R46

R15

R1

R1

B97

B97

B47

ECM

E

17

1
2

5
3

6
4

2
1

6

1

14

B136

CANISTER

DRAIN
VALVE

MAIN RELAY

BATTERY

7

R144

R67

B97

B47

3

4

1

2

5

6

B136

R213

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

1 2

1 2

3

4 5 6 7 8

EN-05232

EN(H6DO)(diag)-242

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?

Check for poor
contact of the 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(H6DO)-16,
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

EN(H6DO)(diag)-243

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CF:DTC P0448 EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL

CIRCUIT SHORTED

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-126, DTC P0448 EVAPORATIVE EMISSION CONTROL
SYSTEM VENT CONTROL CIRCUIT SHORTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

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

SBF-7

R144

R67

R213

R46

R15

R1

R1

B97

B97

B47

ECM

E

17

1
2

5
3

6
4

2
1

6

1

14

B136

CANISTER

DRAIN
VALVE

MAIN RELAY

BATTERY

7

R144

R67

B97

B47

3

4

1

2

5

6

B136

R213

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

1 2

1 2

3

4 5 6 7 8

EN-05232

EN(H6DO)(diag)-244

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

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

Connector & terminal

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

Is the voltage 10 V or more?

Repair the short
circuit to the power
supply in the har-
ness between the
ECM and drain
valve connector.

Go to step 2.

2

CHECK DRAIN VALVE.
1) Turn the ignition switch to OFF.
2) Measure the resistance between drain valve
terminals.

Terminals

No. 1 — No. 2:

Is the resistance less than 1

:? Replace the drain

valve. <Ref. to
EC(H6DO)-16,
Drain Valve.>

Repair the poor
contact of ECM
connector.