Nissan Frontier D22. Manual - part 647

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

EC-1691

[VG33ER]

C

D

E

F

G

H

I

J

K

L

M

A

EC

3. 

CHECK VACUUM CUT VALVE BYPASS VALVE OPERATION

 Without CONSULT-II

1.

Turn ignition switch OFF.

2.

Remove vacuum cut valve and vacuum cut valve bypass valve as an assembly.

3.

Apply vacuum to port A and check that there is no suction from
port B.

4.

Apply vacuum to port B and check that there is suction from port
A.

5.

Blow air in port B and check that there is a resistance to flow out
of port A.

6.

Disconnect vacuum cut valve bypass valve harness connector.

7.

Supply battery voltage to the terminal.

8.

Blow air in port A and check that air flows freely out of port B.

9.

Blow air in port B and check that air flows freely out of port A.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 5.

4. 

CHECK EVAP PURGE LINE

1.

Check EVAP purge line between EVAP canister and fuel tank for clogging or disconnection.

2.

Check EVAP purge port of fuel tank for clogging.

3.

Check EVAP canister. Refer to 

EC-1741, "EVAPORATIVE EMISSION LINE DRAWING"

 .

OK or NG

OK

>> GO TO 8.

NG (Step 1)>>Repair it.
NG (Step 2)>>Clean EVAP purge port.
NG (Step 3)>>Replace EVAP canister.

5. 

CHECK BYPASS HOSE

Check bypass hoses for clogging.

OK or NG

OK

>> GO TO 6.

NG

>> Repair or replace hoses.

PBIB0635E

EC-1692

[VG33ER]

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

6. 

CHECK VACUUM CUT VALVE BYPASS VALVE

 With CONSULT-II

1.

Perform “VC/V BYPASS/V” in “ACTIVE TEST” mode.

2.

Check air passage continuity and operation delay time under the
following conditions.

Operation takes less than 1 second.

 Without CONSULT-II

Check air passage continuity and operation delay time under the fol-
lowing conditions.

Operation takes less than 1 second.

OK or NG

OK

>> GO TO 7.

NG

>> Replace vacuum cut valve bypass valve.

SEF014Z

Condition

VC/V BYPASS/V

Air passage continuity between A and B

ON

Yes

OFF

No

PBIB1429E

Condition

Air passage continuity between A and B

12V direct current supply between ter-
minals 1 and 2

Yes

No supply

No

PBIB1430E

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

EC-1693

[VG33ER]

C

D

E

F

G

H

I

J

K

L

M

A

EC

7. 

CHECK VACUUM CUT VALVE

Check vacuum cut valve as follows:

1.

Plug port C  and D  with fingers.

2.

Apply vacuum to port A  and check that there is no suction from
port B .

3.

Apply vacuum to port B  and check that there is suction from
port A .

4.

Blow air in port B  and check that there is a resistance to flow out
of port A .

5.

Open port C  and D .

6.

Blow air in port A  check that air flows freely out of port C .

7.

Blow air in port B  check that air flows freely out of port D .

OK or NG

OK

>> GO TO 8.

NG

>> Replace vacuum cut valve.

8. 

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR HOSE

1.

Turn ignition switch OFF.

2.

Check disconnection or improper connection of hose connected to EVAP control system pressure sensor.

OK or NG

OK

>> GO TO 9.

NG

>> Repair or replace.

9. 

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR

1.

Disconnect EVAP control system pressure sensor harness con-
nector.

2.

Check connectors for water.
Water should not exist.

OK or NG

OK

>> GO TO 10.

NG

>> Replace EVAP control system pressure sensor.

10. 

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR FUNCTION

Refer to DTC P0452 

EC-1524, "DTC Confirmation Procedure"

  or P0453 

EC-1530, "DTC Confirmation Proce-

dure"

 .

OK or NG

OK

>> GO TO 11.

NG

>> Replace EVAP control system pressure sensor.

SEF379Q

AEC651A

EC-1694

[VG33ER]

DTC P1491 VACUUM CUT VALVE BYPASS VALVE

11. 

CHECK EVAP CANISTER VENT CONTROL VALVE

 With CONSULT-II

1.

Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.

2.

Check air passage continuity and operation delay time.

Operation takes less than 1 second.

 Without CONSULT-II 

1.

Check air passage continuity and operation delay time under the
following condition.

Operation takes less than 1 second.

If NG or operation takes more than 1 second, clean valve using air
blower or replace as necessary.
If portion B  is rusted, replace control valve.
Make sure new O-ring is installed properly.
OK or NG

OK

>> GO TO 12. 

NG

>> Replace EVAP canister vent control valve.

Condition VENT CONTROL/V

Air passage continuity between 

A and B

ON

No

OFF

Yes

SEF013Z

Condition

Air passage continuity between A 

and B

12V direct current supply 
between terminals 1 and 2

No

OFF

Yes

BBIA0309E