2008 INFINITI QX56 fuel pressure

FL-12
< REMOVAL AND INSTALLATION >
FUEL TANK
REMOVAL
WARNING:
Follow the “General Precautions” before working on the fuel system. Refer to FL-4, "
General Precau-
tion" .
1. Drain the fuel from the fuel tank, if necessary. • Position the vehicle so it is level.
2. Remove the fuel filler cap to release the pressure from inside the fuel tank.
3. Check the fuel level on level gauge. If the fuel gauge indicates more than the level as shown (full or almost full), drain the fuel
from the fuel tank until the fuel gauge indicates the level as
shown, or less.
• If the fuel pump does not operate, use the following procedure
to drain the fuel to the specified level after disconnecting the
fuel filler hose from the fuel filler pipe.
a. Insert a suitable hose of less than 15 mm (0.59 in) diameter into the fuel filler pipe through the fuel filler opening to drain the fuel
from fuel filler pipe.
b. Insert a suitable hose into the fuel tank through the fuel filler hose to drain the fuel from the fuel tank.
• As a guide, the fuel level reaches the fuel gauge position as shown, or less, when approximately 14
liters (3 3/4 US gal, 3 1/8 Imp gal) of fuel are drained from the fuel tank.
4. Remove the LH rear wheel and tire. Refer to WT-48, "
Rotation" .
5. Remove the four clips and remove the rear fender protector, front.
6. Disconnect the fuel filler hose from the fuel filler pipe and dis- connect the vent hose quick connector.
7. Release the fuel pressure from the fuel lines. Refer to EC-494, "
Fuel Pressure Check" .
8. Disconnect the battery negative terminal.
9. Remove the second row seat and the third row LH seat. Refer to SE-54, "
Removal and Installation" (sec-
ond row), SE-62, "
LH Side Seat" (third row).
10. Remove the second and third row rear seat belt buckles mounted on the floor. Refer to SB-7, "
Removal
and Installation of Second Row Seat Belt", SB-9, "Removal and Installation of Third Row Seat Belt".
11. Remove the LH center pillar trim, the LH rear trim panel, and the LH rear side door kick plate and weather
stripping. Refer to INT-14, "
Removal and Installation" .
12. Remove the second row rear center console and base. Refer to IP-21, "
Removal and Installation" .
13. Reposition the floor carpet out of the way to access the inspection hole cover, located under the center LH
rear seat.
13. Fuel filler hose grommet 14. Fuel filler cap 15. Fuel tank shield
16. Clip 17. Fuel filler pipe shield
WBIA0390E
LBIA0386E
Revision: March 2010 2008 QX56

FUEL TANKFL-15
< REMOVAL AND INSTALLATION >
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22. If necessary, remove the lock ring using Tool.
23. If necessary, remove the fuel level sensor, fuel filter, and fuel
pump assembly. Discard the fuel level sensor, fuel filter, and fuel
pump assembly O-ring.
CAUTION:
• Do not bend the float arm during removal.
• Avoid impacts such as droppi ng when handling the com-
ponents.
INSTALLATION
Installation is in the reverse order of removal.
• For installation, use a new fuel level sensor, fuel filter, and fuel pump assembly O-ring.
• Connect the quick connector as follows:
- Check the connection for any damage or foreign materials.
- Align the connector with the pipe, t hen insert the connector straight into the pipe until a click is heard.
- After connecting the quick connector, make sure that the connec-
tion is secure by checking as follows:
- Pull the tube and the connector to make sure they are securely connected.
- Visually inspect the connector to make sure the two retainer tabs are securely connected.
INSPECTION AFTER INSTALLATION
1. Turn the ignition switch ON but do not start en gine, then check the fuel pipe and hose connections for
leaks while applying fuel pressure.
2. Start the engine and rev it above idle, then check that there are no fuel leaks at any of the fuel pipe and
hose connections. Tool number : — (J-46536)
LBIA0389E
PBIC1653E
Revision: March 2010
2008 QX56

ON-VEHICLE SERVICEFSU-7
< ON-VEHICLE MAINTENANCE >
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ON-VEHICLE MAINTENANCE
ON-VEHICLE SERVICE
Front Suspension PartsINFOID:0000000001534627
Check front suspension parts for excessive play, cracks, wear and
other damage.
• Shake each front wheel to check for excessive play. If looseness is noted, inspect wheel bearing end play, then check
ball joint end play. Refer to FA X - 6 , "
On-Vehicle Inspection and Ser-
vice" and FSU-7, "Front Suspension Parts".
• Make sure that the cotter pin is inserted (4WD only).
• Retighten all nuts and bolts to the specified torque.
• Check shock absorber for oil leakage and other damage.
• Check suspension ball joint for grease leakage and ball joint dust cover for cracks and other damage.
Front Wheel AlignmentINFOID:0000000004915023
PRELIMINARY INSPECTION
WARNING:
Always adjust the alignment with the vehicle on a flat surface.
NOTE:
If alignment is out of specificat ion, inspect and replace any damaged or worn suspension parts before making
any adjustments.
1. Check and adjust the wheel alignment with the vehicle under unladen conditions. “Unladen conditions”
means that the fuel, coolant, and lubricant are full; and that the spare tire, jack, hand tools and mats are in
their designated positions.
2. Check the tires for incorrect air pressure and excessive wear.
3. Check the wheels for run out and damage. Refer to WT-45, "
Inspection".
4. Check the wheel bearing axial end play. Refer to FAX-6, "
On-Vehicle Inspection and Service" .
5. Check the shock absorbers for leaks or damage.
6. Check each mounting point of the suspension components for any excessive looseness or damage.
7. Check each link, arm, and the rear suspension member for any damage.
8. Check the vehicle height. Refer to FSU-25, "
Wheelarch Height (Unladen*1)" .
GENERAL INFORMATION AND RECOMMENDATIONS
1. A Four-Wheel Thrust Alignment should be performed.
• This type of alignment is re commended for any NISSAN vehicle.
• The four-wheel “thrust” process helps ensure that the vehicle is properly aligned and the steering wheel
is centered.
• The alignment machine itself should be ca pable of accepting any NISSAN vehicle.
• The alignment machine should be checked to ensure that it is level.
2. Make sure the alignment machine is properly calibrated. Suspension component torques : Refer to
FSU-14,
"Component" . SMA525A
SFA392B
Revision: March 2010 2008 QX56

GI-16
< HOW TO USE THIS MANUAL >
TERMINOLOGY
TERMINOLOGY
SAE J1930 Terminology ListINFOID:0000000001539196
All emission related terms used in this publication in accordance with SAE J1930 are listed. Accordingly, new
terms, new acronyms/abbreviations and old terms are listed in the following chart.
NEW TERMNEW ACRONYM /
ABBREVIATION OLD TERM
Air cleaner ACL Air cleaner
Barometric pressure BARO ***
Barometric pressure sensor-BCDD BAROS-BCDD BCDD
Camshaft position CMP ***
Camshaft position sensor CMPSCrank angle sensor
Canister *** Canister
Carburetor CARBCarburetor
Charge air cooler CACIntercooler
Closed loop CLClosed loop
Closed throttle position switch CTP switchIdle switch
Clutch pedal position switch CPP switch Clutch switch
Continuous fuel injection system CFI system***
Continuous trap oxidizer system CTOX system ***
Crankshaft position CKP***
Crankshaft position sensor CKPS***
Data link connector DLC***
Data link connector for CONSULT-III DLC for CONSULT-IIIDiagnostic connector for CONSULT-III
Diagnostic test mode DTMDiagnostic mode
Diagnostic test mode selector DTM selectorDiagnostic mode selector
Diagnostic test mode I DTM I Mode I
Diagnostic test mode II DTM IIMode II
Diagnostic trouble code DTCMalfunction code
Direct fuel injection system DFI system ***
Distributor ignition system DI system Ignition timing control
Early fuel evaporation-mixture heater EFE-mixture heater Mixture heater
Early fuel evaporation system EFE system Mixture heater control
Electrically erasable programmable read
only memory EEPROM
***
Electronic ignition system EI systemIgnition timing control
Engine control EC ***
Engine control module ECM ECCS control unit
Engine coolant temperature ECT Engine temperature
Engine coolant temperature sensor ECTS Engine temperature sensor
Engine modification EM ***
Engine speed RPM Engine speed
Erasable programmable read only memory EPROM ***
Evaporative emission canister EVAP canister Canister
Evaporative emission system EVAP system Canister control solenoid valve
Exhaust gas recirculation valve EGR valve EGR valve
Revision: March 2010 2008 QX56

TERMINOLOGYGI-17
< HOW TO USE THIS MANUAL >
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Exhaust gas recirculation control-BPT
valve EGRC-BPT valve
BPT valve
Exhaust gas recirculation control-solenoid
valve EGRC-solenoid valve
EGR control solenoid valve
Exhaust gas recirculation temperature sen-
sor EGRT sensorExhaust gas temperature sensor
EGR temperature sensor
Flash electrically erasable programmable
read only memory FEEPROM
***
Flash erasable programmable read only
memory FEPROM
***
Flexible fuel sensor FFS***
Flexible fuel system FF system***
Fuel pressure regulato r*** Pressure regulator
Fuel pressure regulator control solenoid
valve ***
PRVR control solenoid valve
Fuel trim FT***
Heated Oxygen sensor HO2S Exhaust gas sensor
Idle air control system IAC system Idle speed control
Idle air control valve-air regulato rIACV-air regulator Air regulator
Idle air control valve-auxiliary air control
valve IACV-AAC valve
Auxiliary air control (AAC) valve
Idle air control valve-FICD solenoid valve IACV-FICD solenoid valve FICD solenoid valve
Idle air control valve-idle up control sole-
noid valve IACV-idle up control solenoid valve Idle up control solenoid valve
Idle speed control-FI pot ISC-FI pot FI pot
Idle speed control system ISC system***
Ignition control IC***
Ignition control module ICM***
Indirect fuel injection system IFI system ***
Intake air IA Air
Intake air temperature sensor IAT sensor Air temperature sensor
Knock *** Detonation
Knock sensor KS Detonation sensor
Malfunction indicator lamp MIL Check engine light
Manifold absolute pressure MAP ***
Manifold absolute pressure sensor MAPS ***
Manifold differential pressure MDP ***
Manifold differential pressure sensor MDPS ***
Manifold su rface temperature MST ***
Manifold surface temperature sensor MSTS ***
Manifold vacuum zone MVZ ***
Manifold vacuum zone sensor MVZS***
Mass air flow sensor MAFS Air flow meter
Mixture control solenoid valve MC solenoid valveAir-fuel ratio control solenoid valve
Multiport fuel injection System MFI system Fuel injection control
NEW TERM
NEW ACRONYM /
ABBREVIATION OLD TERM
Revision: March 2010
2008 QX56

PRECAUTIONSGI-27
< PRECAUTION >
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system. The connectors should be disconnected only when working according to the WORK FLOW of
TROUBLE DIAGNOSES in EC and TM sections.
Three Way CatalystINFOID:0000000001539210
If a large amount of unburned fuel flows into the catalyst, the catalyst temperature will be excessively high. To
prevent this, follow the instructions.
• Use unleaded gasoline only. Leaded gasoline will seriously damage the three way catalyst.
• When checking for ignition spark or measuring engine compression, make tests quickly and only when nec-
essary.
• Do not run engine when the fuel tank level is low, otherwise the engine may misfire, causing damage to the
catalyst.
Do not place the vehicle on flammable material. Keep flammable material off the exhaust pipe and the three
way catalyst.
Precaution for Fuel (Unlead ed Premium Gasoline Recommended)INFOID:0000000006211825
INFINITI recommends the use of unleaded premium gasoline with an octane rating of at least 91 AKI (Anti-
Knock Index) number (Research octane number 96).
If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of at least 87
AKI number (Research octane number 91) can be us ed, but only under the following precautions:
• have the fuel tank filled only partially with unleaded regular gasoline, and fill up with unleaded premium gas- oline as soon as possible.
• avoid full throttle driving and abrupt acceleration.
However, for maximum vehicle performance, the u se of unleaded premium gasoline is recommended.
CAUTION:
Do not use leaded gasoline. Usin g leaded gasoline will damage the three way catalyst. Using a fuel
other than that specified could adversely affect the emission cont rol devices and systems, and could
also affect the warranty coverage validity.
Multiport Fuel Inje ction System or Engine Control SystemINFOID:0000000001539213
• Before connecting or disconnecting any harness connector for the
multiport fuel injection system or ECM:
Turn ignition switch to “OFF” position.
Disconnect negative battery terminal.
Otherwise, there may be damage to ECM.
• Before disconnecting pressurized fuel line from fuel pump to injec- tors, be sure to release fuel pressure.
• Be careful not to jar components such as ECM and mass air flow
sensor.
HosesINFOID:0000000001539214
HOSE REMOVAL AND INSTALLATION
• To prevent damage to rubber hose, do not pry off rubber hose withtapered tool or screwdriver.
SGI787
SMA019D
Revision: March 2010 2008 QX56

LAN-46
< FUNCTION DIAGNOSIS >[CAN]
CAN COMMUNICATION SYSTEM
NOTE:
CAN data of the air bag diagnosis sensor unit is not us
ed by usual service work, thus it is omitted.
Tire pressure data signal R T
Tire pressure signal R TR
Turn indicator signal TR
Buzzer output signal TR
Door lock/unlock request signal RT
Hazard request signal RT
Hazard warning lamp request signal RT
Ignition knob switch signal RT
KEY warning signal TR
LOCK warning signal TR
Panic alarm request signal RT
Power window open request signal RT
1st position switch signal R T
4th position switch signal R T
Distance to empty signal RT
Fuel level low warning signal RT
Fuel level sensor signal R T
Parking brake switch signal RT
Seat belt buckle switch signal RT
Stop lamp switch signal R T
Tow mode switch signal R T
Vehicle speed signal RRR RRR R T
RRRT
Steering angle sensor signal TR
ABS malfunction signal RT
ABS warning lamp signal RT
Brake pressure sensor signal RT
Brake warning lamp signal RT
SLIP indicator lamp signal RT
TCS malfunction signal RT
VDC malfunction signal RT
VDC OFF indicator lamp signal RRT
VDC operation signal RT
Front wiper stop position signal RT
High beam status signal R T
Hood switch signal RT
Low beam status signal R T
Rear window defogger control signal R RT
Ambient sensor signal RT
Signal name/Connecting unit
ECM
TCM
LASER ICC
ADP
AV
BCM
HVAC I-KEY M&A
STRG 4WDABS
IPDM-E
Revision: March 2010 2008 QX56

ENGINE MAINTENANCEMA-17
< ON-VEHICLE MAINTENANCE >
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2. Fill the radiator and the reservoir tank (to the “MAX”
line), with water. Reinstall the radiator cap and leave
the vented reservoir cap off.
3. Run the engine until it reaches normal operating temperature.
4. Press the engine accelerator two or three times under no-load.
5. Stop the engine and wait until it cools down.
6. Drain the water from the engine cooling system. Refer to CO-11, "
Changing Engine Coolant" .
7. Repeat steps 2 through 6 until clear water begins to drain from the radiator.
Checking Fuel LineINFOID:0000000001606172
Inspect the fuel lines and fuel tank for improper mounting, leaks,
cracks, damage, loose connections, chafing, or deterioration.
As necessary, repair or replace any faulty parts.
Changing Fuel FilterINFOID:0000000001606173
The fuel filter is part of the fuel level sensor unit, fuel filter and fuel pump assembly. Refer to FL-7, "Removal
and Installation" .
WARNING:
Before replacing the fuel filter, release the fuel pressure from the fuel system. Refer to EC-494, "
Fuel
Pressure Check".
Changing Engine Air Cleaner FilterINFOID:0000000001606174
VISCOUS PAPER TYPE
NOTE:
• The viscous paper type filter does not need cleaning between replacement intervals.
• Replace the air filter as necessary for required maintenance.
1. Remove the air duct and resonator assembly.
SMA803A
1. Air cleaner case (upper) 2. Air cleaner filter3. Air cleaner case (lower)
4. Air duct and resonator assembly
WBIA0465E
Revision: March 2010 2008 QX56