2008 INFINITI QX56 Fuel

P0455 EVAP CONTROL SYSTEMEC-261
< COMPONENT DIAGNOSIS > [VK56DE]
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OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3.CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-272, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
5.CHECK EVAP PURGE LINE
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks, improper connection or
disconnection.
Refer to EC-37, "
Description".
OK or NG
OK >> GO TO 6.
NG >> Repair or reconnect the hose.
6.CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
>> GO TO 7.
7.CHECK EVAP CANISTER VENT CONTROL VALVE
Check the following.
• EVAP canister vent control valve is installed properly. Refer to EC-498, "
Removal and Installation".
• EVAP canister vent control valve.
Refer to EC-241, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Repair or replace EVAP canister vent control valve and O-ring.
8.INSTALL THE PRESSURE PUMP
To locate the EVAP leak, install EVAP service port adapter and pres-
sure pump to EVAP service port securely.
NOTE:
Improper installation of the EV AP service port adapter to the
EVAP service port may cause leaking.
BBIA0366E
Revision: March 2010 2008 QX56

EC-264
< COMPONENT DIAGNOSIS >[VK56DE]
P0455 EVAP CONTROL SYSTEM
OK >> GO TO 16.
NG >> Replace EVAP canister purge volume control solenoid valve.
16.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-190, "
Component Inspection".
OK or NG
OK >> GO TO 17.
NG >> Replace fuel level sensor unit.
17.CHECK EVAP CONTROL SYS TEM PRESSURE SENSOR
Refer to EC-248, "
Component Inspection".
OK or NG
OK >> GO TO 18.
NG >> Replace EVAP control system pressure sensor.
18.CHECK EVAP/ORVR LINE
Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kink, looseness and improper con-
nection. For location, refer to EC-416
.
OK or NG
OK >> GO TO 19.
NG >> Repair or replace hoses and tubes.
19.CHECK RECIRCULATION LINE
Check recirculation line between filler neck tube and f uel tank for clogging, kink, cracks, looseness and
improper connection.
OK or NG
OK >> GO TO 20.
NG >> Repair or replace hose, tube or filler neck tube.
20.CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-418, "
Component Inspection".
OK or NG
OK >> GO TO 21.
NG >> Replace refueling EVAP vapor cut valve with fuel tank.
21.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351637
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FILLER CAP)
1. Wipe clean valve housing.
SEF445Y
Revision: March 2010 2008 QX56

P0455 EVAP CONTROL SYSTEMEC-265
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2. Check valve opening pressure and vacuum.
3. If out of specificat
ion, 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. Pressure:
15.3 - 20.0 kPa (0.156 - 0.204 kg/cm
2, 2.22 -
2.90 psi)
Vacuum: −6.0 to −3.3 kPa ( −0.061 to −0.034 kg/cm
2,
− 0.87 to −0.48 psi)
SEF943S
Revision: March 2010 2008 QX56

EC-266
< COMPONENT DIAGNOSIS >[VK56DE]
P0456 EVAP CONTROL SYSTEM
P0456 EVAP CONTROL SYSTEM
On Board Diagn
osis LogicINFOID:0000000001351633
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 sm all leak, the very small leak P0456 will be detected.
If ECM judges a leak equivalent to a smal l 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 replacemen t. If an incorrect fuel filler cap is used, the
MIL may come on.
• If the fuel filler cap is not tigh tened 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
Revision: March 2010 2008 QX56

P0456 EVAP CONTROL SYSTEMEC-267
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DTC Confirmation ProcedureINFOID:0000000001351634
NOTE:
•
If DTC P0456 is displayed with P0442, firs t 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 conduc ted, 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 ar e met just before the DTC confir mation 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 11V 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 - 1.4V
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, wait at least 10 seconds and then turn ON.
4. Select “EVP V/S LEAK P0456/P1456” of “EV APORATIVE 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-268, "
Diagnosis Procedure".
NOTE:
• If the engine speed cannot be maintained within the range disp layed on CONSULT-III screen, go
to EC-13, "
Basic Inspection".
• Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid
valve properly.
Overall Function CheckINFOID:0000000001351635
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
2 , 0.6 psi).
1. Attach the EVAP service port adapter securely to the EVAP ser- vice port.
BBIA0366E
Revision: March 2010 2008 QX56

EC-268
< COMPONENT DIAGNOSIS >[VK56DE]
P0456 EVAP CONTROL SYSTEM
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 EV
AP 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-268, "
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 ProcedureINFOID:0000000001351636
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 proper ly by rotating the cap clockwise.
OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3.CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-272, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
SEF462UI
SEF915U
Revision: March 2010 2008 QX56

P0456 EVAP CONTROL SYSTEMEC-271
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OK (With CONSULT-III)>>GO TO 12.
OK (Without CONSULT-III)>>GO TO 13.
NG >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check the following.
• EVAP canister for damage
• EVAP hose between EVAP canister and vehi cle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
12.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-III
1. Disconnect vacuum hose to EVAP canister purge volu me control solenoid valve at EVAP service port.
2. Start engine.
3. Perform “PURG VOL CONT/V ” in “ACTIVE TEST” mode.
4. Touch “Qu” on CONSULT-III screen to increase “PURG VOL CONT/V” opening to 100%.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
OK or NG
OK >> GO TO 15.
NG >> GO TO 14.
13.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volu me control solenoid valve at EVAP service port.
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
OK or NG
OK >> GO TO 16.
NG >> GO TO 14.
14.CHECK VACUUM HOSE
Check vacuum hoses for clogging or disconnection. Refer to EC-37, "
Description".
OK or NG
OK >> GO TO 15.
NG >> Repair or reconnect the hose.
15.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-238, "
Component Inspection".
OK or NG
OK >> GO TO 16.
NG >> Replace EVAP canister purge volume control solenoid valve.
16.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-190, "
Component Inspection" .
OK or NG
OK >> GO TO 17.
NG >> Replace fuel level sensor unit.
17.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-248, "
Component Inspection".
Vacuum should exist.
Vacuum should exist.
Revision: March 2010
2008 QX56

EC-272
< COMPONENT DIAGNOSIS >[VK56DE]
P0456 EVAP CONTROL SYSTEM
OK or NG
OK >> GO TO 18.
NG >> Replace EVAP control system pressure sensor.
18.CHECK EVAP PURGE LINE
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks or improper connection.
Refer to EC-37, "
Description".
OK or NG
OK >> GO TO 19.
NG >> Repair or reconnect the hose.
19.CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
>> GO TO 20.
20.CHECK EVAP/ORVR LINE
Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kink, looseness and improper con-
nection. For location, refer to EC-416
.
OK or NG
OK >> GO TO 21.
NG >> Repair or replace hoses and tubes.
21.CHECK RECIRCULATION LINE
Check recirculation line between filler neck tube and f uel tank for clogging, kink, cracks, looseness and
improper connection.
OK or NG
OK >> GO TO 22.
NG >> Repair or replace hose, tube or filler neck tube.
22.CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-418, "
Component Inspection".
OK or NG
OK >> GO TO 23.
NG >> Replace refueling EVAP vapor cut valve with fuel tank.
23.CHECK FUEL LEVEL SENSOR
Refer to MWI-34, "
Component Inspection".
OK or NG
OK >> GO TO 24.
NG >> Replace fuel level sensor unit.
24.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351638
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FILLER CAP)
Revision: March 2010 2008 QX56