Infiniti F50. Manual - part 479

DTC P1448 EVAP CANISTER VENT CONTROL VALVE

EC-557

C

D

E

F

G

H

I

J

K

L

M

A

EC

4. 

CHECK IF EVAP CANISTER SATURATED WITH WATER

1.

Remove EVAP canister with EVAP canister vent control valve attached.

2.

Check if water will drain from the EVAP canister.

Yes or No

Yes

>> GO TO 5.

No

>> GO TO 7.

5. 

CHECK EVAP CANISTER

Weigh the EVAP canister with the EVAP canister vent control valve attached.
The weight should be less than 1.8 kg (4.0 lb).

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

6. 

DETECT MALFUNCTIONING PART

Check the following.

●

EVAP canister for damage

●

EVAP hose between EVAP canister and water separator for clogging or poor connection

>> Repair hose or replace EVAP canister.

7. 

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR HOSE

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

OK

>> GO TO 8.

NG

>> Repair it.

8. 

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR

1.

Disconnect EVAP control system pressure sensor harness connector.

2.

Check connectors for water.

OK or NG

OK

>> GO TO 9.

NG

>> Replace EVAP control system pressure sensor.

9. 

CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR

Refer to 

EC-365, "Component Inspection"

 .

OK or NG

OK

>> GO TO 10.

NG

>> Replace EVAP control system pressure sensor.

SEF596U

Water should not exist.

EC-558

DTC P1448 EVAP CANISTER VENT CONTROL VALVE

10. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

EBS00ML8

EVAP CANISTER VENT CONTROL VALVE

With CONSULT-II

1.

Remove EVAP canister vent control valve from EVAP canister.

2.

Check portion B  of EVAP canister vent control valve for being
rusted.

3.

Reconnect harness connectors disconnected.

4.

Turn ignition switch “ON”.

5.

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

6.

Check air passage continuity and operation delay time.

7.

Clean the air passage (Portion A  to B ) of EVAP canister vent
control valve using an air blower.

8.

Perform Test No. 9 again.

With GST

1.

Remove EVAP canister vent control valve from EVAP canister.

2.

Check portion B  of EVAP canister vent control valve for being
rusted.

3.

Check air passage continuity and operation delay time under the
following conditions.
Make sure new O-ring is installed properly.

4.

Clean the air passage (Portion A  to B ) of EVAP canister vent
control valve using an air blower.

5.

Perform Test No. 9 again.

SEF337X

PBIB0153E

SEF337X

PBIB0154E

DTC P1456 EVAP CONTROL SYSTEM

EC-559

C

D

E

F

G

H

I

J

K

L

M

A

EC

DTC P1456 EVAP CONTROL SYSTEM

PFP:14710

On Board Diagnosis Logic

EBS00ML9

This diagnosis detects very small leaks in the EVAP line between fuel tank and EVAP canister purge volume
control solenoid valve, using vapor pressure in the fuel tank in the same way as conventional EVAP small leak
diagnosis.
If ECM judges a leak which corresponds to a very small leak, the very small leak P0456 will be detected.
If ECM judges a leak equivalent to a small leak, EVAP small leak P1442 will be detected.
If ECM judges there are no leaks, the diagnosis will be OK.

CAUTION:

●

Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used,
the MIL may come on.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0456
0456

Evaporative emission 
control system very 
small leak (negative 
pressure check)

●

EVAP system has a very small leak.

●

EVAP system does not operate prop-
erly.

●

Incorrect fuel tank vacuum relief valve

●

Incorrect fuel filler cap used

●

Fuel filler cap remains open or fails to close.

●

Foreign matter caught in fuel filler cap.

●

Leak is in line between intake manifold and EVAP 
canister purge volume control solenoid valve.

●

Foreign matter caught in EVAP canister vent con-
trol valve.

●

EVAP canister or fuel tank leaks

●

EVAP purge line (pipe and rubber tube) leaks

●

EVAP purge line rubber tube bent

●

Blocked or bent rubber tube to EVAP control sys-
tem pressure sensor

●

Loose or disconnected rubber tube

●

EVAP canister vent control valve and the circuit

●

EVAP canister purge volume control solenoid 
valve and the circuit

●

Absolute pressure sensor

●

Fuel tank temperature sensor

●

O-ring of EVAP canister vent control valve is miss-
ing or damaged

●

Water separator

●

EVAP canister is saturated with water

●

EVAP control system pressure sensor

●

Refueling control valve

●

ORVR system leaks

●

Fuel level sensor and the circuit

●

Foreign matter caught in EVAP canister purge vol-
ume control solenoid valve

SEF323U

EC-560

DTC P1456 EVAP CONTROL SYSTEM

●

If the fuel filler cap is not tightened properly, the MIL may come on.

●

Use only a genuine NISSAN rubber tube as a replacement.

DTC Confirmation Procedure

EBS00MLA

NOTE:

●

If DTC P1456 is displayed with P1442, perform TROUBLE DIAGNOSIS FOR DTC P1456 first.

●

After repair, make sure that the hoses and clips are installed properly.

●

If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and
wait at least 10 seconds before conducting the next test.

TESTING CONDITION:

●

Open engine hood before conducting following procedure.

●

If any of following conditions are met just before the DTC confirmation procedure, leave the vehi-
cle for more than 1 hour.

–

Fuel filler cap is removed.

–

Refilled or drained the fuel.

–

EVAP component parts is/are removed.

●

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

 WITH CONSULT-II

1.

Turn ignition switch “ON” and select “DATA MONITOR” mode with CONSULT-II.

2.

Make sure the following conditions are met.
FUEL LEVEL SE: 0.25 - 1.15V
COOLAN TEMP/S: 0 - 32

°

C (32 - 90

°

F)

FUEL T/TMP SE: 0 - 35

°

C (32 - 95

°

F)

INT A/TEMP SE: More than 0

°

C (32

°

F)

If NG, turn ignition switch “OFF” and leave the vehicle in a cool
place (soak the vehicle) or refilling/draining fuel until the output
voltage condition of the “FUEL LEVEL SE” meets within the
range above and leave the vehicle for more than 1 hour. Then
start from step 1). 

3.

Turn ignition switch “OFF” and wait at least 10 seconds.

4.

Turn ignition switch “ON”.

5.

Select “EVAP V/S LEAK P0456/P1456” of “EVAPORATIVE
SYSTEM” in “DTC WORK SUPPORT” mode with CONSULT-II.
Follow the instruction displayed.

6.

Make sure that “OK” is displayed.
If “NG” is displayed, refer to 

EC-562, "Diagnostic Procedure"

 .

NOTE:

●

If the engine speed cannot be maintained within the range displayed on CONSULT-II screen, go
to 

EC-82, "Basic Inspection"

 .

●

Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid
valve properly.

PBIB1953E

PBIB0837E