Nissan Frontier D22. Manual - part 346

DTC P1456 EVAP CONTROL SYSTEM

EC-487

[KA24DE]

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EC

DTC P1456 EVAP CONTROL SYSTEM

PFP:14710

On Board Diagnosis Logic

UBS00DBR

This diagnosis detects very small leaks in the EVAP line between fuel tank and EVAP canister purge volume
control solenoid valve, using of vapor pressure in the fuel tank.
The EVAP canister vent control valve is closed to shut the EVAP purge line. The vacuum cut valve bypass
valve will then be opened to clear the line between the fuel tank and the EVAP canister purge volume control
solenoid valve. The EVAP control system pressure sensor can now monitor the pressure inside the fuel tank.
If pressure increases, the ECM will check for leaks in the line between the vacuum cut valve and EVAP canis-
ter purge volume control solenoid valve.
If ECM judges a leak which corresponds to a very small leak, the very small leak P1456 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.

PBIB1402E

EC-488

[KA24DE]

DTC P1456 EVAP CONTROL SYSTEM

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.

●

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

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Use only a genuine NISSAN rubber tube as a replacement.

DTC Confirmation Procedure

UBS00DBS

NOTE:

●

If DTC P0456 or P1456 is displayed with P0442, first perform trouble diagnosis for DTC P0456 or
P1456.

●

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

●

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 5 seconds before conducting the next test.

 WITH CONSULT-II

TESTING CONDITION:

●

Open engine hood before conducting following procedure.

●

If any of following condition is met just before the DTC confirmation procedure, leave the vehicle
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.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1456

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

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EVAP system has a very small 
leak.

●

EVAP system does not operate 
properly.

●

Incorrect fuel tank vacuum relief valve

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Incorrect fuel filler cap used

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Fuel filler cap remains open or fails to close.

●

Foreign matter caught in fuel filler cap.

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Leak is in line between intake manifold and EVAP can-
ister purge volume control solenoid valve.

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Foreign matter caught in EVAP canister vent control 
valve.

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EVAP canister or fuel tank leaks

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EVAP purge line (pipe and rubber tube) leaks

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EVAP purge line rubber tube bent

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Blocked or bent rubber tube to EVAP control system 
pressure sensor

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Loose or disconnected rubber tube

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EVAP canister vent control valve and the circuit

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EVAP canister purge volume control solenoid valve 
and the circuit

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Fuel tank temperature sensor

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

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Water separator

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EVAP canister is saturated with water

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EVAP control system pressure sensor

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Refueling control valve

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ORVR system leaks

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Fuel level sensor and the circuit

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Foreign matter caught in EVAP canister purge volume 
control solenoid valve

DTC P1456 EVAP CONTROL SYSTEM

EC-489

[KA24DE]

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EC

1.

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

2.

Make sure the following conditions are met.
FUEL LEVEL SE: 1.16 - 0.25V
COOLAN TEMP/S: 0 - 32

°C (32 - 90°F)

FUEL T/TMP SE: 0 - 32

°C (32 - 90°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 5 seconds.

4.

Turn ignition switch ON.

5.

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

6.

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

EC-490, "Diagnostic Procedure"

 .

NOTE:

●

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

EC-74, "Basic Inspection"

 .

Overall Function Check

UBS00DBT

 WITH GST

Use this procedure to check the overall function of the EVAP very small leak function. During this check, a 1st
trip DTC might not be confirmed.

CAUTION:

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Never use compressed air, doing so may damage the EVAP system.

●

Do not start engine.

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Do not exceeded 4.12 kPa (0.042 kg/cm

2

 , 0.6 psi).

1.

Attach the EVAP service port adapter securely to the EVAP service port.

2.

Set the pressure pump and a hose.

3.

Also set a vacuum gauge via 3-way connector and a hose.

4.

Turn ignition switch ON.

5.

Connect GST and select MODE 8.

6.

Using MODE 8 control the EVAP canister vent control valve
(close) and vacuum cut valve bypass valve (open).

7.

Apply pressure and make sure the following conditions are sat-
isfied.
Pressure to be applied: 2.7 kPa (20 mmHg, 0.79 inHg)
Time to be waited after the pressure drawn in to the EVAP
system and the pressure to be dropped: 60 seconds and
the pressure should not be dropped more than 0.4 kPa (3 mmHg, 0.12 inHg)
If NG, go to 

EC-490, "Diagnostic Procedure"

 .

PBIB1953E

PBIB0837E

SEF462UA

EC-490

[KA24DE]

DTC P1456 EVAP CONTROL SYSTEM

If OK, go to next step.
NOTE:
For more information, refer to GST instruction manual.

8.

Disconnect GST.

9.

Start engine and warm it up to normal operating temperature.

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

11. Restart engine and let it idle for 90 seconds.
12. Keep engine speed at 2,000 rpm for 30 seconds.

13. Turn ignition switch OFF.

Diagnostic Procedure

UBS00DBU

1. 

CHECK FUEL FILLER CAP DESIGN

1.

Turn ignition switch OFF.

2.

Check for genuine NISSAN fuel filler cap design.

OK or NG

OK

>> GO TO 2.

NG

>> Replace with genuine NISSAN fuel filler cap.

2. 

CHECK FUEL FILLER CAP INSTALLATION 

●

Check that the cap is tightened properly by rotating the cap clockwise.

OK or NG

OK

>> GO TO 3.

NG

>>

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Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.

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Retighten until ratcheting sound is heard.

3. 

CHECK FUEL FILLER CAP FUNCTION

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Check for air releasing sound while opening the fuel filler cap.

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 4.

SEF915U