2011 INFINITI QX56 fuel pressure

P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-317
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0443 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE
DTC LogicINFOID:0000000006288307
DTC DETECTION LOGIC
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.
TESTING CONDITION:
 Perform “DTC CONFIRMATION PROCEDURE” when the fuel level is between 1/4 and 3/4 full, and
vehicle is placed on flat level surface.
 Always perform test at a temperature of 5 to 60 °C (41 to 140 °F).
 Cool the vehicle so that engi ne coolant temperature becomes same level as ambient temperature.
Do you have CONSULT-III
YES >> GO TO 2.
NO >> GO TO 4.
2.PERFORM DTC CONFIRMATION PROCEDURE A
WITH CONSULT-III
1. Turn ignition switch ON.
2. Check that the following condition are met. FUEL T/TMP SE: 0 - 35 °C (32 - 95 °F)
3. Start engine and wait at least 60 seconds.
4. Check 1st trip DTC.
IS 1st trip DTC detected?
OK >> Proceed to EC-318, "Diagnosis Procedure".
NG >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE B
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON.
6. Select “PURG VOL CN/V P1444” of “EVAPORA TIVE SYSTEM” in “DTC WORK SUPPORT” mode with
CONSULT-III.
7. Touch “START”.
8. Start engine and let it idle until “TESTING” on CO NSULT-III changes to “COMPLETED”. (It will take
approximately 10 seconds.)
If “TESTING” is not displayed afte r 5 minutes, retry from step 2.
9. Touch “SELF-DIAG RESULTS”.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0443 PURG VOLUME CONT/V
(EVAP canister purge vol-
ume control solenoid valve) A
The canister purge flow is detected dur-
ing the vehicle is stopped while the en-
gine is running, even when EVAP
canister purge volume control solenoid
valve is completely closed.  EVAP control system pressure sensor
 EVAP canister purge volume control
solenoid valve
(The valve is stuck open.)
 EVAP canister vent control valve
 EVAP canister
 Hoses (Hoses are connected incorrectly or
clogged.)
B
The canister purge flow is detected dur-
ing the specified driving conditions, even
when EVAP canister purge volume con-
trol solenoid valve is completely closed.
Revision: 2010 May2011 QX56

EC-336
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0452 EVAP CONTROL S
YSTEM PRESSURE SENSOR
P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
DTC LogicINFOID:0000000006288319
DTC DETECTION LOGIC
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.
TESTING CONDITION:
Always perform test at a temperature of 5 °C (41 °F) or more.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON.
6. Select “DATA MONITOR” mode with CONSULT-III.
7. Check that “FUEL T/TM P SE” is more than 0°C (32 °F).
8. Start engine and wait at least 20 seconds.
9. Check 1st trip DTC.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes to ECM harness connector terminals under the following conditions.
3. Check that the voltage is less than 4.2 V.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON.
6. Turn ignition switch OFF and wait at least 10 seconds.
7. Start engine and wait at least 20 seconds.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0452 EVAP SYS PRES SEN
(EVAP control system pres-
sure sensor low input) An excessively low voltage from
the sensor is sent to ECM.  (EVAP control system pressure sensor circuit is short-
ed.)
Harness or connectors
(Battery current sensor circuit is open or shorted.)
(Accelerator pedal position sensor 2 circuit is shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Crankshaft position sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
 EVAP control system pressure sensor
 Battery current sensor
 Accelerator pedal position sensor
 Camshaft position sensor (bank 1)
 Crankshaft position sensor
 Refrigerant pressure sensor
ECM
Connector +–
Terminal Terminal
E80 134
(Fuel tank temperature sensor signal) 175
Revision: 2010 May2011 QX56

P0453 EVAP CONTROL SYSTEM PRESSURE SENSOREC-341
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0453 EVAP CONTROL SYSTEM
PRESSURE SENSOR
DTC LogicINFOID:0000000006288322
DTC DETECTION LOGIC
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.
TESTING CONDITION:
Always perform test at a temperature of 5 °C (41 °F) or more.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON.
6. Select “DATA MONITOR” mode with CONSULT-III.
7. Check that “FUEL T/TM P SE” is more than 0°C (32 °F).
8. Start engine and wait at least 20 seconds.
9. Check 1st trip DTC.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes to ECM harness connector terminals under the following conditions.
3. Check that the voltage is less than 4.2 V.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0453 EVAP SYS PRES SEN
(EVAP control system pres-
sure sensor high input) An excessively high voltage
from the sensor is sent to
ECM.  Harness or connectors
(EVAP control system pressure sensor circuit is short-
ed.)
(Crankshaft position sensor circuit is open or shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Accelerator pedal position sensor 2 circuit is shorted.)
(Battery current sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
 EVAP control system pressure sensor
 Crankshaft position sensor
 Camshaft position sensor (bank 1)
 Accelerator pedal position sensor 2
 Battery current sensor
 Refrigerant pressure sensor
 EVAP canister vent control valve
 EVAP canister
 Rubber hose from EVAP canister vent control valve to
vehicle frame
ECM Ground
Connector +–
Terminal Terminal
E80 134
(Fuel tank temperature sensor signal) 175
Revision: 2010 May2011 QX56

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

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
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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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