2011 INFINITI QX56 Fuel

EC-346
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0456 EVAP CONTROL SYSTEM
P0456 EVAP CONTROL SYSTEM
DTC LogicINFOID:0000000006288325
DTC DETECTION LOGIC
This diagnosis detects leaks in the EVAP line between f
uel tank and EVAP canister purge volume control sole-
noid valve, using the negative pressure caused by decrease of fuel temperature in the fuel tank after turning
ignition switch OFF.
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 illuminate.
 If the fuel filler cap is not tightened properly, the MIL may illuminate.
 Use only a genuine NISSAN rubber tube as a replacement.
DTC CONFIRMATION PROCEDURE
PBIB1026E
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0456 Evaporative emission control
system leak  EVAP system has a leak.
 EVAP system does not op-
erate properly.  Incorrect fuel tank vacuum relief valve
 Incorrect fuel filler cap used
 Fuel filler cap remains open or does not close.
 Foreign matter caught in fuel filler cap.
 Leak is in line between intake manifold and EVAP canis-
ter purge volume control solenoid valve.
 Foreign matter caught in EVAP canister vent control 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 missing 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 volume control solenoid valve
Revision: 2010 May2011 QX56

P0456 EVAP CONTROL SYSTEMEC-347
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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1.PRECONDITIONING
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.
Do you have CONSULT-III?
YES >> GO TO 2.
NO >> GO TO 4.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
WITH CONSULT-III
1. Turn ignition switch ON and select “EVAP DIAG READY” in “DATA MONITOR” mode with CONSULT-III.
2. Start engine and wait at idle until “OFF” of “EVAP DIAG READY” changes to “ON”.
NOTE:
It will take at most 2 hours until “OFF” of “EVAP DIAG READY” changes to “ON”.
3. Turn ignition switch OFF and wait at least 90 minutes. NOTE:
Never turn ignition swit ch ON during 90 minutes.
4. Turn ignition switch ON and select “EVAP LEAK DIAG” in “DATA MONITOR” mode with CONSULT-III.
5. Check that “EVAP LEAK DIAG” indication.
Which is displayed on CONSULT-III?
CMPLT >> GO TO 3.
YET >> Perform DTC CONFIRMATION PROCEDURE again. GO TO 1.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-347, "Diagnosis Procedure".
NO >> INSPECTION END.
4.PERFORM DTC CONFIRMATION PROCEDURE
WITH GST
1. Start engine and wait engine idle for at least 2 hours.
2. Turn ignition switch OFF and wait at least 90 minutes.
NOTE:
Never turn ignition swit ch ON during 90 minutes.
3. Turn ignition switch ON.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-347, "Diagnosis Procedure".
NO >> INSPECTION END.
Diagnosis ProcedureINFOID:0000000006288326
1.CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch OFF.
2. Check for genuine NISSAN fuel filler cap design.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace with genuine NISSAN fuel filler cap.
SEF915U
Revision: 2010 May2011 QX56

EC-348
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0456 EVAP CONTROL SYSTEM
2.CHECK FUEL FILLER CAP INSTALLATION
Check that the cap is tightened proper ly by rotating the cap clockwise.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Open fuel filler cap, then clean cap and fuel filler neck threads using air blower. Then retighten until reteaching sound is heard.
3.CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-350, "
Component Inspection (Fuel Filler Cap)".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace fuel filler cap with a genuine one.
5.CHECK FOR EVAP LEAK
Refer to FL-12, "
Inspection".
Is there any leak in EVAP line?
YES >> Repair or replace.
NO >> GO TO 6.
6.CHECK EVAP CANISTER VENT CONTROL VALVE
Check the following.
 EVAP canister vent control valve is installed properly. Refer to FL-10, "
Exploded View".
 EVAP canister vent control valve. Refer to EC-327, "
Component Inspection (EVAP Cani ster Vent Control Valve)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace EVAP canister vent control valve and O-ring. Refer to FL-10, "
Exploded View".
7.CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister (1) with EVAP canister vent control valve (2) and EVAP control system pressure sensor attached.
2. Check if water will drain from the EVAP canister.
Does water drain from EVAP canister?
YES >> GO TO 8.
NO-1 >> With CONSULT-III: GO TO 10.
NO-2 >> Without CONSULT-III: GO TO 11.
8.CHECK EVAP CANISTER
Weigh the EVAP canister assembly with the EVAP canister vent control valve and EVAP control system pres-
sure sensor attached. Refer to FL-10, "
Exploded View".
The weight should be less than 2.5 kg (5.5 lb).
Is the inspection result normal?
YES-1 >> With CONSULT-III: GO TO 10.
YES-2 >> Without CONSULT-III: GO TO 11.
NO >> GO TO 9.
JSBIA0692ZZ
Revision: 2010 May2011 QX56

P0456 EVAP CONTROL SYSTEMEC-349
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9.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. Refer to FL-10, "
Hydraulic Layout".
10.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 and let it idle.
3. Select “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.
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12.
11 .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.
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12.
12.CHECK VACUUM HOSE
Check vacuum hoses for clogging or disconnection. Refer to FL-10, "
Hydraulic Layout".
Is the inspection result normal?
YES >> GO TO 13.
NO >> Repair or reconnect the hose.
13.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-320, "
Component Inspection (EVAP Canister Purge Volume Control Solenoid Valve)".
Is the inspection result normal?
YES >> GO TO 14.
NO >> Replace EVAP canister purge volume control solenoid valve. Refer to FL-10, "
Exploded View".
14.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-273, "
Component Inspection (Fuel Tank Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 15.
NO >> Replace fuel level sensor unit. Refer to FL-5, "
Removal and Installation".
15.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-335, "
Component Inspection (EVAP Control System Pressure Sensor)".
Is the inspection result normal?
YES >> GO TO 16. Vacuum should exist.
Vacuum should exist.
Revision: 2010 May2011 QX56

EC-350
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0456 EVAP CONTROL SYSTEM
NO >> Replace EVAP control system pressure sensor. Refer to
EC-335, "Component Inspection (EVAP
Control System Pressure Sensor)".
16.CHECK EVAP PURGE LINE
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks or improper connection.
Refer to FL-10, "
Hydraulic Layout".
Is the inspection result normal?
YES >> GO TO 17.
NO >> Repair or reconnect the hose.
17.CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
>> GO TO 18.
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 FL-10, "
Hydraulic Layout".
Is the inspection result normal?
YES >> GO TO 19.
NO >> Repair or replace hoses and tubes.
19.CHECK RECIRCULATION LINE
Check recirculation line between fuel filler tube and fuel tank for clogging, kink, cracks, looseness and
improper connection.
Is the inspection result normal?
YES >> GO TO 20.
NO >> Repair or replace hose, tube or fuel filler tube. Refer to FL-8, "
Exploded View".
20.CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-518, "
Component Inspection (EVAP Vapor Cut Valve)".
Is the inspection result normal?
YES >> GO TO 21.
NO >> Replace refueling EVAP vapor cut valve with fuel tank. Refer to FL-10, "
Exploded View".
21.CHECK FUEL LEVEL SENSOR
Refer to MWI-70, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 22.
NO >> Replace fuel level sensor unit. Refer to FL-5, "
Removal and Installation".
22.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Fuel Filler Cap)INFOID:0000000006288327
1.CHECK FUEL FILLER CAP
1. Turn ignition switch OFF.
2. Remove fuel filler cap.
Revision: 2010 May2011 QX56

P0456 EVAP CONTROL SYSTEMEC-351
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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3. Wipe clean valve housing.
4. Install fuel filler cap adapter (commercial service tool) to fuel
filler cap.
5. Check valve opening pressure and vacuum.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.REPLACE FUEL FILLER CAP
Replace fuel filler cap.
CAUTION:
Use only a genuine fuel filler cap as a replacement. If an incorrect fuel filler cap is used, the MIL may
illuminate.
>> INSPECTION END
SEF445Y
Pressure: 15.3 - 20.0 kPa (0.156 - 0.204 kg/cm2, 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: 2010 May2011 QX56

EC-352
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0460 FUEL LEVEL SENSOR
P0460 FUEL LEVEL SENSOR
DTC LogicINFOID:0000000006288328
DTC DETECTION LOGIC
NOTE:

If DTC P0460 is displayed with DTC UXXXX, first perform the tr ouble diagnosis for DTC UXXXX.
 If DTC P0460 is displayed with DTC P0607, first pe rform the trouble diagnosis for DTC P0607. Refer
to EC-378, "
DTC Logic".
When the vehicle is parked, the fuel level in the fuel tank is naturally stable. It means that output signal of the
fuel level sensor does not change. If ECM senses sloshi ng signal from the sensor, fuel level sensor malfunc-
tion is detected.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
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.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and wait maximum of 2 consecutive minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-352, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288329
1.CHECK DTC WITH “COMBINATION METER”
Refer to MWI-30, "
CONSULT-III Function".
Is any DTC detected?
YES >> Perform trouble diagnosis of detected DTC.
NO >> GO TO 2.
2.CHECK FUEL LEVEL SENSOR SIGNAL CIRCUIT
Check fuel level sensor signal circuit. Refer to MWI-69, "
Component Function Check".
Is the inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Perform trouble diagnosis of fuel level sensor signal circuit. Refer to MWI-69,
"DiagnosisProcedure".
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0460 FUEL LEV SEN SLOSH
(Fuel level sensor circuit
noise) Even though the vehicle is parked, a
signal being varied is sent from the
fuel level sensor to ECM.  Harness or connectors
(The CAN communication line is open or shorted)
 Harness or connectors (The sensor circuit is open or shorted)
 Combination meter
 Fuel level sensor
Revision: 2010 May2011 QX56

P0461 FUEL LEVEL SENSOREC-353
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0461 FUEL LEVEL SENSOR
DTC LogicINFOID:0000000006288330
DTC DETECTION LOGIC
NOTE:

If DTC P0461 is displayed with DTC UXXXX, first perform the tr ouble diagnosis for DTC UXXXX.
 If DTC P0461 is displayed with DT C P0607, first perform the trouble diagnosis for DTC P0607. Refer
to EC-378, "
DTC Logic".
Driving long distances naturally affect fuel gauge level.
This diagnosis detects the fuel gauge malfunction of the gauge not moving even after a long distance has
been driven.
DTC CONFIRMATION PROCEDURE
1.PERFORM COMPONENT FUNCTION CHECK
Perform Component Function Check. Refer to EC-353, "
Component Function Check".
Use component function check to check the overall function of the fuel level sensor. During this check, a 1st
trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-354, "
Diagnosis Procedure".
Component Function CheckINFOID:0000000006288331
1.PRECONDITIONING
WARNING:
When performing the following procedure, alw ays observe the handling of the fuel. Refer to FL-2,
"General Precautions".
TESTING CONDITION:
Before starting component function check, preparation of draining fuel and refilling fuel is required.
>> GO TO 2.
2.PERFORM COMPONENT FUNCTION CHECK
NOTE:
Start from step 8, if it is possible to confirm that the fuel cannot be drained by 30 (7-7/8 US gal, 6-5/8
Imp gal) in advance.
1. Prepare a fuel container and a spare hose.
2. Release fuel pressure from fuel line. Refer to EC-153, "
Work Procedure".
3. Remove the fuel feed hose on the fuel level sensor unit. Refer to FL-5, "
Removal and Installation".
4. Connect a spare fuel hose where the fuel feed hose was removed.
5. Turn ignition switch ON.
6. Drain fuel by 30 (7-7/8 US gal, 6-5/8 Imp gal) from the fuel tank using proper equipment.
7. Confirm that the fuel gauge indication varies.
8. Fill fuel into the fuel tank for 30 (7-7/8 US gal, 6-5/8 Imp gal).
9. Confirm that the fuel gauge indication varies.
Is the inspection result normal?
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0461 FUEL LEVEL SENSOR
(Fuel level sensor circuit
range/performance) The output signal of the fuel level sensor
does not change within the specified
range even though the vehicle has been
driven a long distance.  Harness or connectors
(The CAN communication line is open or short-
ed)
 Harness or connectors (The sensor circuit is open or shorted)
 Combination meter
 Fuel level sensor
Revision: 2010 May2011 QX56