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Infiniti QX56 (JA60). Manual - part 402

EC-260

< COMPONENT DIAGNOSIS >

[VK56DE]

P0455 EVAP CONTROL SYSTEM

Component Inspection

INFOID:0000000005149280

FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FILLER CAP)

1. Wipe clean valve housing.

2. Check valve opening pressure and vacuum.

3. If out of specification, replace fuel filler cap as an assembly.

CAUTION:

Use only a genuine fuel filler cap as a replacement. If an incor-

rect fuel filler cap is used, the MIL may come on.

SEF445Y

Pressure: 15.3 - 20.0 kPa (0.156 - 0.204 kg/cm

, 2.22 -

2.90 psi)

Vacuum:

−6.0 to −3.3 kPa (−0.061 to −0.034 kg/cm

−0.87 to −0.48 psi)

SEF943S

P0456 EVAP CONTROL SYSTEM

EC-261

< COMPONENT DIAGNOSIS >

[VK56DE]

P0456 EVAP CONTROL SYSTEM

On Board Diagnosis Logic

INFOID:0000000005149281

This diagnosis detects very small leaks in the EVAP line between fuel tank and EVAP canister purge volume

control solenoid valve, using the intake manifold vacuum 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 P0442 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.

• 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 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
• Loose or disconnected rubber tube
• EVAP canister vent control valve and the circuit
• EVAP canister purge volume control solenoid

valve and the circuit

• Fuel tank temperature sensor
• O-ring of EVAP canister vent control valve is miss-

ing or damaged

• EVAP canister is saturated with water
• EVAP control system pressure sensor
• Refueling EVAP vapor cut valve
• ORVR system leaks
• Fuel level sensor and the circuit
• Foreign matter caught in EVAP canister purge vol-

ume control solenoid valve

PBIB1026E

EC-262

< COMPONENT DIAGNOSIS >

[VK56DE]

P0456 EVAP CONTROL SYSTEM

DTC Confirmation Procedure

INFOID:0000000005149282

NOTE:

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

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

• If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next step.

1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:

• Open engine hood before conducting following procedure.

• If any of following conditions are met just before the DTC confirmation procedure, leave the vehicle

for more than 1 hour.

- Fuel filler cap is removed.

- Fuel is refilled or drained.

- EVAP component parts is/are removed.

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

WITH CONSULT-III

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

2. Make sure the following conditions are met.

FUEL LEVEL SE: 0.25 - 1.4 V

COOLAN TEMP/S: 0 - 30

°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, wait at least 10 seconds and then turn ON.

4. Select “EVP V/S LEAK P0456/P1456” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode

with CONSULT-III.

Follow the instruction displayed.

5. Make sure that “OK” is displayed.

If “NG” is displayed, refer to

EC-263, "Diagnosis Procedure"

NOTE:

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

EC-13, "Basic Inspection"

• Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid

valve properly.

Overall Function Check

INFOID:0000000005149283

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:

• Do not use compressed air, doing so may damage the EVAP system.

• Do not start engine.
• Do not exceeded 4.12 kPa (0.042 kg/cm

, 0.6 psi).

P0456 EVAP CONTROL SYSTEM

EC-263

< COMPONENT DIAGNOSIS >

[VK56DE]

1. Attach the EVAP service port adapter (commercial service tool)

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 Service $08.

6. Using Service $08, control the EVAP canister vent control valve

(close).

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-263, "Diagnosis Procedure"

If OK, go to next step.

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.

NOTE:

For more information, refer to GST Instruction Manual.

Diagnosis Procedure

INFOID:0000000005149284

CHECK FUEL FILLER CAP DESIGN

1. Turn ignition switch OFF.

2. Check for genuine NISSAN fuel filler cap design.
OK or NG

>> GO TO 2.

>> Replace with genuine NISSAN fuel filler cap.

CHECK FUEL FILLER CAP INSTALLATION

Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG

>> GO TO 3.

>> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.

2. Retighten until ratcheting sound is heard.

BBIA0366E

SEF462UI

SEF915U

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