2004 INFINITI QX56 low oil pressure

EM-30Revision: August 2007
FUEL INJECTOR AND FUEL TUBE
2004 QX56
7. Remove the fuel injector from the fuel tube using the following
steps.
a. Spread open and remove the clip.
b. Remove the fuel injector from the fuel tube by pulling straight
out.
CAUTION:

Be careful with remaining fuel that may leak out from fuel
tube.

Do not damage injector nozzles during removal.

Do not bump or drop fuel injectors.

Do not disassemble fuel injectors.
8. Remove the fuel damper from each fuel tube.
INSTALLATION
1. Install the fuel damper to each fuel tube using the following
steps.
a. Apply engine oil to the new O-ring and set it into the cap of the
fuel tube.
CAUTION:

Handle O-ring with bare hands. Never wear gloves.

Lubricate new O-ring with new engine oil.

Do not clean O-ring with solvent.

Make sure that O-ring and its mating part are free of for-
eign material.

When installing O-ring, do not scratch it with tool or fin-
gernails.

Do not twist or stretch the O-ring.
b. Make sure that the backup spacer is in the O-ring connecting surface of the fuel damper.
NOTE:
The backup spacer is part of the fuel damper assembly.
c. Insert the fuel damper until it seats on the fuel tube.
CAUTION:

Insert straight, making sure that the axis is lined up.

Do not pressure-fit with excessive force.
d. Install the cap, and then tighten the bolts evenly.

After tightening the bolts, make sure that there is no gap between the cap and fuel tube.
2. Install new O-rings to the fuel injector paying attention to the items below.
CAUTION:

Upper and lower O-ring are different.
KBIA2506E
Reference value :130 N (13.3 kg, 29.2 lb)
KBIA2473E

EM-32Revision: August 2007
FUEL INJECTOR AND FUEL TUBE
2004 QX56

Lubricate O-ring with new engine oil.

Do not clean O-ring with solvent.

Make sure that O-ring and its mating part are free of foreign material.

When installing O-ring, be careful not to scratch it with tool or fingernails. Also be careful not to
twist or stretch O-ring. If O-ring was stretched while it was being attached, do not insert it
quickly into fuel tube.

Insert new O-ring straight into fuel tube. Do not twist it.
6. Installation of the remaining components is in the reverse order of removal.
INSPECTION AFTER INSTALLATION
After installing the fuel tubes, make sure there are no fuel leaks at the connections using the following steps.
1. Apply fuel pressure to the fuel lines by turning the ignition switch ON (with engine stopped). Then check
for fuel leaks at the connections.
NOTE:
Use mirrors for checking on hidden points.
2. Start the engine and rev it up and check for fuel leaks at connections.
CAUTION:
Do not touch the engine immediately after stopping, as engine becomes extremely hot.

CYLINDER HEAD
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Revision: August 20072004 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00ILS
CHECKING COMPRESSION PRESSURE
1. Warm up engine thoroughly. Then stop engine.
2. Release fuel pressure. Refer to EC-46, "
FUEL PRESSURE RELEASE" .
a. Remove fuel pump fuse, and start engine.
Refer to PG-78, "
FUSE AND RELAY BOX" or fuel pump fuse location.

Let fuel pump fuse removed until the end of step 7.
b. After engine stalls, crank it two or three times to release all fuel pressure.
3. Remove ignition coil and spark plug from each cylinder.
Refer to EM-27, "
REMOVAL" .
4. Connect engine tachometer (not required in use of CONSULT-II).
5. Install compression tester with Tool into spark plug hole.
6. With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge
pointer stabilizes, read the compression pressure and engine rpm. Perform these steps to check each cyl-
inder.
Unit: kPa (kg/cm2 , psi) /rpm
CAUTION:
Always use a fully charged battery to obtain specified engine speed.

If the engine speed is out of specified range, check battery liquid for proper gravity. Check engine
speed again with normal battery gravity.

If compression pressure is below minimum value, check valve clearances and parts associated with
combustion chamber (valve, valve seat, piston, piston ring, cylinder bore, cylinder head, cylinder head
gasket). After the checking, measure compression pressure again.

If some cylinders have low compression pressure, pour small amount of engine oil into the spark plug
hole of the cylinder to re-check it for compression.
–If the added engine oil improves the compression, the piston rings may be worn out or damaged. Check
the piston rings and replace if necessary.
–If the compression pressure remains at low level despite the addition of engine oil, the valves may be
malfunctioning. Check the valves for damage. Replace the valve or valve seat accordingly.

If two adjacent cylinders have respectively low compression pressure and their compression remains
low even after the addition of engine oil, the gaskets may be leaking, or valve in adjacent cylinders may
be damaged. Inspect and repair as required.
7. After inspection is complete, install removed parts. Installation is in the reverse order of removal.
8. Start engine, and confirm that engine runs smoothly.
9. Perform trouble diagnosis. If DTC appears, erase it. Refer to EC-71, "
TROUBLE DIAGNOSIS" . Tool number : EG15050500 (J-45402)
WBIA0605E
Standard MinimumDeference limit
between cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 300

EM-72Revision: August 2007
ENGINE ASSEMBLY
2004 QX56
INSPECTION AFTER INSTALLATION

Before starting engine, check the levels of engine coolant, engine oil and working fluid. If less than
required quantity, fill to the specified level.

Use procedure below to check for fuel leakage.

Turn ignition switch ON (with engine stopped). With fuel pressure applied to fuel piping, check for fuel
leakage at connection points.

Start engine. With engine speed increased, check again for fuel leakage at connection points.

Run engine to check for unusual noise and vibration.

Warm up engine thoroughly to make sure there is no leakage of engine coolant, engine oil, working fluid,
fuel and exhaust gas.

Bleed air from passages in pipes and tubes of applicable lines, such as in cooling system.

After cooling down engine, again check amounts of engine coolant, engine oil and working fluid. Refill to
specified level, if necessary.

Summary of the inspection items:
*Transmission/transaxle/CVT fluid, power steering fluid, brake fluid, etc.Item Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Working fluid* Level Leakage Level
Fuel — Leakage —
Exhaust gas — Leakage —

IDX-4
ALPHABETICAL INDEX
Driver air bag .................................................. SRS-45
DTC work support ............................................ EC-113
DTRL - Wiring diagram ....................................... LT-37
Duct and grilles .............................................. ATC-157
DVD Player ........................................................ AV-59
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ECM input/output signal ..................................... EC-96
ECM power supply ............................. EC-128, EC-361
ECM relay ........................................................ EC-128
ECM/PW - Wiring diagram ............................... EC-362
ECTS - Wiring diagram .................................... EC-167
Electric sunroof .................................................. RF-10
Electric throttle control actuator ......... EC-365, EC-367
Electrical load signal circuit .............................. EC-612
Electrical units location ...................................... PG-64
Electronic ignition (EI) system ........................... EC-28
Engine control circuit diagram ........................... EC-94
Engine control component parts location ........... EC-88
Engine control module (ECM) .......................... EC-351
Engine control system diagram and chart ......... EC-23
Engine coolant .................................................... CO-8
Engine coolant temperature sensor (ECTS) ... EC-165,
EC-178
Engine fail-safe system ...................................... EC-77
Engine oil ............................................................. LU-7
Engine oil filter replacement ............................. MA-16
Engine oil precautions .......................................... GI-7
Engine oil replacement ..................................... MA-16
Engine removal ................................................. EM-70
Engine room cover ............................................ EM-11
Engine serial number .......................................... GI-48
ETC1 - Wiring diagram .................................... EC-368
ETC2 - Wiring diagram .................................... EC-375
ETC3 - Wiring diagram .................................... EC-379
EVAP canister .................................................. EC-636
EVAP canister purge volume control solenoid valve ....
EC-285
, EC-496
EVAP canister vent control valve ....... EC-292, EC-504
EVAP control system (small leak) diagnosis .. EC-276,
EC-316
, EC-324
EVAP control system pressure sensor .... EC-299, EC-
302, EC-308
EVAP control system purge flow monitoring diagnosis
EC-271
EVAP vapor lines inspection ............................. MA-19
Evaporative emission (EVAP) system ............. EC-633
Evaporator ..................................................... ATC-175
Exhaust manifold .............................................. EM-19
Exhaust system ................................................... EX-3
Exhaust system inspection .................................. EX-3
Expansion valve ............................................. ATC-177
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F/FOG - Wiring diagram ..................................... LT-71
F/PUMP - Wiring diagram ................................ EC-602
Final drive pre-inspection .................. FFD-15, RFD-12
Final drive removal and installation ... FFD-12, RFD-10
Flow charts .......................................................... GI-27
Fluid temperature sensor (A/T) ........................ AT-131
Fluids ................................................................ MA-10
Fluorescent leak detector .............................. ATC-178
Fog lamp, front ................................................... LT-69
Foot lamp ......................................................... LT-129
Freeze frame data ............................... EC-54, EC-107
Front brake solenoid valve ................. AT-151, AT-154
Front bumper ...................................................... EI-13
Front case (Transfer) ....................................... TF-125
Front combination lamp removal and installation LT-33
Front door ............................. BL-129, BL-132, GW-69
Front Door Trim ................................................... EI-31
Front drive shaft (Transfer) .............................. TF-115
Front fog lamp .................................................... LT-69
Front passenger air bag .................................. SRS-50
Front seat ........................................................... SE-96
Front seat belt ...................................................... SB-3
Front seat belt pre-tensioner ............... SRS-3, SRS-57
Front washer ...................................................... WW-4
Front wiper ......................................................... WW-4
FTTS - Wiring diagram ...................... EC-227, EC-232
Fuel cut control (at no load high engine speed) EC-30
Fuel filter replacement ......................................... FL-5
Fuel gauge ............................................................ DI-5
Fuel injection system (Bank 1) .......... EC-208, EC-217
Fuel injection system (Bank 2) .......... EC-208, EC-217
Fuel injector and fuel tube ................................. EM-29
Fuel level sensor ................. EC-334, EC-336, EC-338
Fuel line inspection .............................................. FL-3
Fuel precautions ................................................... GI-5
Fuel pressure check .......................................... EC-46
Fuel pressure release ....................................... EC-46
Fuel pump ....................................................... EC-601
Fuel pump and gauge .......................................... FL-5
Fuel system .......................................................... FL-3
Fuel tank .............................................................. FL-9
Fuel tank temperature sensor ........... EC-225, EC-231
Fuel tank vacuum relief valve ......................... EC-636
FUELB1 - Wiring diagram ................. EC-210, EC-219
FUELB2 - Wiring diagram ................. EC-211, EC-220
Fuse ...................................................... PG-67, PG-77
Fuse and fusible link box .................................. PG-77
Fuse block ......................................................... PG-76
Fusible link ............................................ PG-67, PG-77
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Garage jack and safety stand ............................. GI-40
Gauges ................................................................. DI-5
Generator .......................................................... SC-17
Generic scan tool (GST) ................................. EC-116
Glass ...................................... GW-11, GW-69, GW-72
Glove box lamp ................................... LT-152, LT-153
GPS antenna ..................................................... AV-62
Grease .............................................................. MA-10
Ground distribution ............................................ PG-30

IDX-5
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IDX
ALPHABETICAL INDEX
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H/AIM - Wiring diagram ...................................... LT-66
H/LAMP - Wiring diagram .................................. LT-10
Handling precautions for plastics ..................... BL-189
Harness connector ............................................ PG-68
Harness layout .................................................. PG-40
Hazard warning lamp ......................................... LT-80
Headlamp ............................................................. LT-6
Headlamp aiming control ................................... LT-65
Headlamp leveler - See Headlamp aiming control . LT-
65
Headlamp removal and installation .................... LT-33
Heated oxygen sensor 2 (bank 1) .... EC-186, EC-196,
EC-383
, EC-395
Heated oxygen sensor 2 (bank 2) .... EC-186, EC-196,
EC-383
, EC-395
Heated oxygen sensor 2 heater (bank 1) ........ EC-138
Heated oxygen sensor 2 heater (bank 2) ........ EC-138
Heated seat ....................................................... SE-89
Heater and cooling unit (Heater core) . ATC-144, ATC-
147
Heater unit (heater core) ............... ATC-144, ATC-147
Height (Dimensions) ........................................... GI-49
HFC134a (R134a) system identification ........... ATC-7
HFC134a (R134a) system precaution ............... ATC-5
HFC134a (R134a) system service procedure ATC-162
HFC134a (R134a) system service tools ......... ATC-14
HFC134a system service equipment precaution ATC-
11
High and low reverse clutch solenoid valve .... AT-163,
AT-166
Horn ................................................................ WW-56
HORN - Wiring diagram .................................. WW-56
How to erase DTC for OBD system .................. EC-62
HSEAT - Wiring diagram ................................... SE-91
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I/MIRR - Wiring diagram ................................... GW-76
IATS - Wiring diagram ..................................... EC-162
ICC - Wiring diagram ....................................... ACS-20
ICC/BS - Wiring diagram ................................. EC-527
ICC/SW - Wiring diagram ................................ EC-512
ICCBOF - Wiring diagram ............................... EC-614
Identification plate .............................................. GI-47
Idle air volume learning ..................................... EC-44
Idle mixture ratio ................................................ EC-33
Idle speed .......................................................... EC-33
Idle speed control (ISC) .................... EC-342, EC-344
Ignition coil .......................................... EM-26, EC-583
Ignition control system .................................... EC-583
Ignition key hole illumination ............................ LT-129
Ignition timing .................................................... EC-33
IGNSYS - Wiring diagram ............................... EC-584
ILL - Wiring diagram ......................................... LT-158
Illumination ....................................................... LT-152
Illumination control .............................. LT-152, LT-169
In vehicle sensor ........................... ATC-128, ATC-137
In-cabin Microfilter ............................................. MA-20
INJECT - Wiring diagram ................................. EC-596
Injector ............................................................. EC-595
Input clutch solenoid valve ................. AT-145, AT-148
Instrument panel .................................................. IP-10
Instrument panel speaker .................................. AV-46
INT/L - Wiring diagram ..................................... LT-135
Intake air temperature sensor ............ EC-161, EC-181
Intake door control linkage adjustment . ATC-78, ATC-
80
Intake door motor ........................... ATC-76, ATC-151
Intake manifold .................................................. EM-15
Intake sensor ................................ ATC-133, ATC-139
Intelligent cruise control (ICC) system ............... ACS-6
Interior ................................................................. EI-34
Interior lamp ...................................................... LT-129
Interior lamp on-off control ................................ LT-129
Internal gear (Transfer) ..................................... TF-127
IPDM (Intelligent power distribution module engine
room) ................................................................. PG-17
IVIS (Infiniti vehicle immobilizer system) precautions ...
GI-3
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Jacking points ..................................................... GI-40
Junction box (J/B) .............................................. PG-76
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Key illumination ................................................ LT-129
Keyless entry system - See Multi-remote control system
BL-44
Knock sensor (KS) ........................................... EC-250
KS - Wiring diagram ........................................ EC-251
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Length (Dimensions) .......................................... GI-49
License lamp .................................................... LT-108
Lifting points ....................................................... GI-41
Line pressure solenoid valve ........................... AT-124
Line pressure switch (Transfer) .......................... TF-95
Line pressure test (A/T) ..................................... AT-59
Liquid gasket application ......................... LU-2, FFD-2
Location of electrical units ................................. PG-64
Low coast brake solenoid valve .......... AT-169, AT-172
Low tire pressure warning system ...................... WT-7
Low tire pressure warning system - trouble diagnoses
WT-10
Low tire pressure warning system - Wiring diagram .....
WT-10
Lubricant (R134a) A/C ..................................... ATC-22
Lubricants .......................................................... MA-10
Lubrication circuit (engine) .................................. LU-5
Lubrication oil A/C ........................................... ATC-22
Lubrication-locks, hinges and hood latches ....... MA-30

IDX-6
ALPHABETICAL INDEX
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MAFS - Wiring diagram ..................... EC-149
, EC-156
Magnet clutch ............................... ATC-104, ATC-167
MAIN - Wiring diagram .................................... EC-128
Main oil pump (Transfer) .................................. TF-122
Mainshaft (Transfer) ........................................ TF-116
Maintenance (engine)Schedule 1 ....................... MA-6
Maintenance (engine)Schedule 2 ....................... MA-8
Major overhaul (Final drive) .............. FFD-14, RFD-13
Major overhaul (Transfer) ................................ TF-110
Malfunction indicator lamp (MIL) ........................ EC-63
Map lamp .......................................................... LT-129
Mass air flow sensor (MAFS) ............. EC-146, EC-154
Meter ..................................................................... DI-5
METER - Wiring diagram .................................... DI-10
MIL data link connectors circuit ....................... EC-631
MIL/DL - Wiring diagram .................................. EC-631
MIRROR - Wiring diagram ................................ GW-99
Misfire .............................................................. EC-243
Mode door control linkage adjustment ............. ATC-65
Mode door motor ............................ ATC-63, ATC-152
Model variation ................................................... GI-46
Multiport fuel injection (MFI) system .................. EC-26
Multiport fuel injection precautions ....................... GI-6
Multi-remote control system ............................... BL-44
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NATS - Wiring diagram .................................... BL-141
NAVI - Wiring diagram ....................................... AV-79
NAVI Control Unit ............................................ AV-157
Neutral-4LO switch ............................................ TF-96
Nissan torque demand (NTD) control system .... EC-29
NVH troubleshooting (AX) ................................. FAX-4
NVH troubleshooting (EM) .................................. EM-9
NVH troubleshooting (Final drive) ..................... RFD-5
NVH troubleshooting (Propeller shaft) ................. PR-3
NVH troubleshooting (RAX) .............................. RAX-4
NVH troubleshooting (RSU) .............................. RSU-5
NVH troubleshooting (ST) .................................... PS-5
NVH troubleshooting (WT)NVH troubleshooting (WT) .
WT-3
NVIS (Nissan vehicle immobilizer system) precautions
GI-3
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O2H2B1 - Wiring diagram ................................ EC-140
O2H2B2 - Wiring diagram ................................ EC-142
O2S2B1 - Wiring diagram .. EC-188, EC-199, EC-386,
EC-398
O2S2B2 - Wiring diagram .. EC-190, EC-201, EC-388,
EC-400
Oil cooler (engine) ............................................. LU-11
Oil filter ............................................................... LU-10
Oil filter (Transfer) ............................................ TF-107
Oil pan (engine) ................................................ EM-22
Oil pressure (engine) ........................................... LU-7
Oil pressure relief valve (engine) ......................... LU-5
Oil pump (engine) .............................................. LU-13
Oil seal replacement (engine) ........................... EM-56
Oil seal replacement (front of final drive) FFD-8, RFD-6
Oil seal replacement (side of final drive) FFD-10, RFD-
8
On board diagnostic system ............................. EC-49
ORVR (On-board Refueling Vapor Recovery) EC-640
Overheat ......................................................... EC-410
P
P/SCKT - Wiring diagram ................................. WW-54
Pantograph jack .................................................. GI-40
Park/Neutral position switch ............................ EC-546
Park/neutral position switch (A/T) .................... AT-109
Parking brake control ........................................... PB-4
Parking lamp .................................................... LT-108
PCV (positive crankcase ventilation) .............. EC-645
Periodic maintenance ......................................... MA-6
Personal lamp .................................................. LT-129
PGC/V - Wiring diagram ................... EC-287, EC-498
PHASE - Wiring diagram ................................ EC-261
Pinion bearing preload diff. ............................. RFD-21
Piston pin inspection ......................................... EM-89
Piston ring inspection ........................................ EM-90
Piston to bore clearance ................................... EM-94
Planetary carrier (Transfer) .............................. TF-127
PNP/SW - Wiring diagram .............................. EC-548
POS - Wiring diagram ..................................... EC-256
POWER - Wiring diagram ................................... PG-6
Power seat ......................................................... SE-88
Power steering fluid level .................................. MA-29
Power steering gear ........................................... PS-15
Power steering oil pump .................................... PS-26
Power steering pressure (PSP) sensor ........... EC-346
Power steering system bleeding .......................... PS-6
Power supply routing .......................................... PG-4
Power window .................................................. GW-15
PRE/SE - Wiring diagram ................. EC-304, EC-310
Precautions (General) ........................................... GI-4
Precautions in repairing high strength steel ..... BL-192
Pressure switch 1 ............................... AT-154, AT-175
Pressure switch 2 ............................................. AT-172
Pressure switch 3 ............................... AT-148, AT-178
Pressure switch 5 ............................... AT-160, AT-181
Pressure switch 6 ............................... AT-166, AT-184
Pressure test (A/T) ............................................. AT-59
Propeller shaft ........................................... PR-4, PR-8
Propeller shaft inspection .................................. MA-24
Propeller shaft on vehicle service ....................... PR-8
Propeller shaft vibration ............................ PR-4, PR-8
PS/SEN - Wiring diagram ............................... EC-347
R
R/VIEW - Wiring diagram .................................... DI-75
Radiator ............................................................ CO-10
Rear Audio Remote Control Unit ....................... AV-47

HEADLAMP (FOR USA)
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Revision: August 20072004 QX56
Aiming AdjustmentEKS007A6
For details, refer to the regulations in your state.
Before performing aiming adjustment, check the following.
1. Ensure all tires are inflated to correct pressure.
2. Place vehicle and screen on level surface.
3. Ensure there is no load in vehicle other than the driver (or equivalent weight placed in driver's position).
Coolant and engine oil filled to correct level, and fuel tank full.
4. Confirm spare tire, jack and tools are properly stowed.
5. Confirm headlamp aiming switch is set to "0" (zero) position.
LOW BEAM AND HIGH BEAM
NOTE:
Aim each headlamp individually and ensure other headlamp beam pattern is blocked from screen.
1. Turn headlamp low beam on.
2. Use adjusting screw to perform aiming adjustment.
WKIA1859E