2004 INFINITI QX56 fuel

EC-270Revision: August 2007
DTC P0420, P0430 THREE WAY CATALYST FUNCTION
2004 QX56
5. CHECK INJECTORS
1. Stop engine and then turn ignition switch ON.
2. Check voltage between ECM terminals 21, 22, 23, 40, 41, 42,
44, 63 and ground with CONSULT-II or tester.
Refer to Wiring Diagram for Injectors, EC-596
.
OK or NG
OK >> GO TO 6.
NG >> Perform EC-597, "
Diagnostic Procedure" .
6. CHECK IGNITION SPARK
1. Turn ignition switch OFF.
2. Disconnect ignition coil assembly from rocker cover.
3. Connect a known-good spark plug to the ignition coil assembly.
4. Disconnect all injector harness connectors.
5. Place end of spark plug against a suitable ground and crank engine.
6. Check for spark.
OK or NG
OK >> GO TO 7.
NG >> Check ignition coil with power transistor and their circuit.
Refer to EC-583, "
IGNITION SIGNAL" .
7. CHECK INJECTOR
1. Turn ignition switch OFF.
2. Remove injector assembly.
Refer to EM-29, "
FUEL INJECTOR AND FUEL TUBE" .
Keep fuel hose and all injectors connected to injector gallery.
3. Disconnect all ignition coil harness connectors.
4. Reconnect injector harness connector.
5. Turn ignition switch ON.
Make sure fuel does not drip from injector.
OK or NG
OK (Does not drip.)>>GO TO 8.
NG (Drips.)>>Replace the injector(s) from which fuel is dripping.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Trouble is fixed.>>INSPECTION END
Trouble is not fixed.>>Replace three way catalyst assembly.Battery voltage should exist.
PBIB1527E
SEF 5 75 Q

EC-272Revision: August 2007
DTC P0441 EVAP CONTROL SYSTEM
2004 QX56
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and let it idle for at least 70 seconds.
4. Select “PURG FLOW P0441” of “EVAPORATIVE SYSTEM” in “DTC CONFIRMATION” mode with CON-
SULT-II.
5. Touch “START”.
If “COMPLETED” is displayed, go to step 7.
6. When the following conditions are met, “TESTING” will be displayed on the CONSULT-II screen. Maintain
the conditions continuously until “TESTING” changes to “COMPLETED”. (It will take at least 35 seconds.)
If “TESTING” is not changed for a long time, retry from step 2.
7. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
273, "Diagnostic Procedure" .
Overall Function CheckUBS00H4M
Use this procedure to check the overall monitoring function of the EVAP control system purge flow monitoring.
During this check, a 1st trip DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
2. Start engine (VDC switch OFF) and warm it up to normal operating temperature.
3. Turn ignition switch OFF, wait at least 10 seconds.
4. Start engine and wait at least 70 seconds.
5. Set voltmeter probes to ECM terminals 32 (EVAP control system
pressure sensor signal) and ground.
6. Check EVAP control system pressure sensor value at idle speed
and note it.
7. Establish and maintain the following conditions for at least 1
minute.
8. Verify that EVAP control system pressure sensor value stays 0.1V less than the value at idle speed (mea-
sured at step 6) for at least 1 second.
Selector lever Suitable position
Vehicle speed 32 - 120 km/h (20 - 75 MPH)
ENG SPEED 500 - 3,000 rpm
B/FUEL SCHDL 1.0 - 12.0 msec
Engine coolant temperature 70 - 100°C (158 - 212°F)
PBIB0826E
Air conditioner switch ON
Headlamp switch ON
Rear window defogger switch ON
Engine speed Approx. 3,000 rpm
Gear position Any position other than P, N or R
PBIB11 09 E

EC-276Revision: August 2007
DTC P0442 EVAP CONTROL SYSTEM
2004 QX56
DTC P0442 EVAP CONTROL SYSTEMPFP:14950
On Board Diagnosis LogicUBS00H4O
This diagnosis detects leaks in the EVAP purge line using engine intake manifold vacuum.
If pressure does not increase, the ECM will check for leaks in the line between the fuel tank and EVAP canister
purge volume control solenoid valve, under the following “Vacuum test” conditions.
The EVAP canister vent control valve is closed to shut the EVAP purge line off. The EVAP canister purge vol-
ume control solenoid valve will then be opened to depressurize the EVAP purge line using intake manifold
vacuum. After this occurs, the EVAP canister purge volume control solenoid valve will be closed.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0442
0442EVAP control system
small leak detected
(negative pressure)EVAP control system has a leak, EVAP
control 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
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

Fuel level sensor and the circuit

Refueling EVAP vapor cut valve

ORVR system leaks
PBIB1026E

DTC P0442 EVAP CONTROL SYSTEM
EC-277
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Revision: August 20072004 QX56
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 Confirmation ProcedureUBS00H4P
NOTE:

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
TESTING CONDITION:

Perform “DTC WORK SUPPORT” 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 0 to 30°C (32 to 86°F).
WITH CONSULT-II
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
4. Make sure that the following conditions are met.
COOLAN TEMP/S: 0 - 70°C (32 - 158°F)
INT/A TEMP SE: 0 - 30°C (32 - 86°F)
5. Select “EVAP SML LEAK P0442/P1442” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-II.
Follow the instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on the CONSULT-II screen, go to
EC-79, "
Basic Inspection" .
6. Make sure that “OK” is displayed.
If “NG” is displayed, refer to EC-278, "
Diagnostic Procedure" .
NOTE:
Make sure that EVAP hoses are connected to EVAP canister
purge volume control solenoid valve properly.
WITH GST
NOTE:
Be sure to read the explanation of EC-59, "
Driving Pattern" before driving vehicle.
1. Start engine.
2. Drive vehicle according to EC-59, "
Driving Pattern" .
PBIB0829E
SEC7 63 C

EC-278Revision: August 2007
DTC P0442 EVAP CONTROL SYSTEM
2004 QX56
3. Stop vehicle.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Select MODE 7 with GST.
–If P0442 is displayed on the screen, go to EC-278, "Diagnostic Procedure" .
–If P0441 is displayed on the screen, go to EC-273, "Diagnostic Procedure" .
Diagnostic ProcedureUBS00H4Q
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 >> 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-636, "
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)" .
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
SEF 9 15 U

DTC P0442 EVAP CONTROL SYSTEM
EC-283
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Revision: August 20072004 QX56
13. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volume 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-24, "
Vacuum Hose Drawing" .
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-290, "
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-229, "
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-301, "
Component Inspection" .
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-634, "
EVAPORATIVE EMISSION LINE DRAWING" .
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. Vacuum should exist.

EC-284Revision: August 2007
DTC P0442 EVAP CONTROL SYSTEM
2004 QX56
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-640, "
ON BOARD REFUELING VAPOR RECOVERY (ORVR)" .
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 fuel 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-643, "
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 DI-22, "
Fuel Level Sensor Unit Inspection" .
OK or NG
OK >> GO TO 24.
NG >> Replace fuel level sensor unit.
24. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END

DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-285
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Revision: August 20072004 QX56
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VA LV E
PFP:14920
DescriptionUBS00H4R
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is
determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor
from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
CONSULT-II Reference Value in Data Monitor ModeUBS00H4S
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
1
EVAP canister
purge flow controlEVAP canister purge vol-
ume control solenoid valve Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
A/F sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor*
2Vehicle speed
PBIB2057E
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/V

Engine: After warming up

Air conditioner switch: OFF

Shift lever: N

No loadIdle
(Accelerator pedal is not depressed
even slightly, after starting engine)0%
2,000 rpm —