torque INFINITI QX56 2004 Factory Owners Manual

ENGINE CONTROL SYSTEM
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Revision: August 20072004 QX56
System ChartUBS00GZD
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This sensor is not used to control the engine system under normal conditions.
*3: This input signal is sent to the ECM through CAN communication line.
*4: This output signal is sent from the ECM through CAN communication line.Input (Sensor) ECM Function Output (Actuator)

Camshaft position sensor (PHASE)

Crankshaft position sensor (POS)

Mass air flow sensor

Engine coolant temperature sensor

A/F sensor 1

Throttle position sensor

Accelerator pedal position sensor

Park/neutral position (PNP) switch

Intake air temperature sensor

Power steering pressure sensor

Ignition switch

Battery voltage

Knock sensor

Refrigerant pressure sensor

Stop lamp switch

ASCD steering switch

ASCD brake switch

Fuel level sensor*1 *3

EVAP control system pressure sensor

Fuel tank temperature sensor*1

Heated oxygen sensor 2*2

TCM (Transmission control module)*3

ABS actuator and electric unit (control unit)*3

Air conditioner switch*3

Wheel sensor*3

Electrical load signal*3
Fuel injection & mixture ratio control Fuel injector
Electronic ignition system Power transistor
Nissan torque demand control system

Electric throttle control actuator

Fuel injector
Fuel pump control Fuel pump relay
ASCD vehicle speed control Electric throttle control actuator
On board diagnostic system
MIL (On the instrument panel)*
4
A/F sensor 1 heater control A/F sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control
Air conditioner relay*
4
Cooling fan control
Cooling fan relay*4
ON BOARD DIAGNOSIS for EVAP system EVAP canister vent control valve

ENGINE CONTROL SYSTEM
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At idle

At low battery voltage

During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Nissan Torque Demand (NTD) Control SystemUBS00GZG
INPUT/OUTPUT SIGNAL CHART
*1: Signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
NTD control system decides the target traction based on the accelerator operation status and the current driv-
ing condition. It then selects the engine torque target by correcting running resistance and atmospheric pres-
sure, and controlling the power-train. Using electric throttle control actuator, it achieves the engine torque
development target which corresponds linearly to the driver's accelerator operation.
Running resistance correction control compares the engine torque estimate value, measured vehicle acceler-
ation, and running resistance on a flat road, and estimates vehicle weight gain and running resistance varia-
tion caused by slopes to correct the engine torque estimate value.
Atmospheric pressure correction control compares the engine torque estimate value from the airflow rate and
the target engine torque for the target traction, and estimates variation of atmospheric pressure to correct the
target engine torque. This system achieves powerful driving without reducing engine performance in the prac-
tical speed range in mountains and high-altitude areas.
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
NTD controlElectric throttle con-
trol actuator and fuel
injector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/Neutral position (PNP) switch Gear position
Power steering pressure sensor Power steering operation
Battery Battery voltage
TCM (CAN communication) A/T control signal
Air conditioner switch*
1Air conditioner operation
ABS actuator and electric unit (control unit)*
1VDC/TCS/ABS operation
Wheel sensor*
1Vehicle speed
Electrical load*
1Electrical load signal

EC-450Revision: August 2007
DTC P1273, P1283 A/F SENSOR 1
2004 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00H9Y
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (Bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 2.6V
58 GR/GApproximately 2.3V
76 G/LApproximately 3.1V
77 BR/BApproximately 2.3V
BBIA0354E
Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E

DTC P1274, P1284 A/F SENSOR 1
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00HA5
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (Bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 2.6V
58 GR/GApproximately 2.3V
76 G/LApproximately 3.1V
77 BR/BApproximately 2.3V
BBIA0354E
Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E

EC-478Revision: August 2007
DTC P1278, P1288 A/F SENSOR 1
2004 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00HAK
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (Bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 2.6V
58 GR/GApproximately 2.3V
76 G/LApproximately 3.1V
77 BR/BApproximately 2.3V
BBIA0354E
Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E

EC-490Revision: August 2007
DTC P1279, P1289 A/F SENSOR 1
2004 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00HAR
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (Bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 2.6V
58 GR/GApproximately 2.3V
76 G/LApproximately 3.1V
77 BR/BApproximately 2.3V
BBIA0354E
Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E

PRECAUTIONS
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PRECAUTIONSPFP:00001
Precautions for Drain Engine CoolantEBS00IKY
Drain engine coolant when engine is cooled.
Precautions for Disconnecting Fuel PipingEBS00IKZ

Before starting work, make sure no fire or spark producing items are in the work area.

Release fuel pressure before disconnecting and disassembly.

After disconnecting pipes, plug openings to stop fuel leakage.
Precautions for Removal and DisassemblyEBS00IL0

When instructed to use special service tools, use the specified tools. Always be careful to work safely,
avoid forceful or uninstructed operations.

Exercise maximum care to avoid damage to mating or sliding surfaces.

Cover openings of engine system with tape or the equivalent, if necessary, to seal out foreign materials.

Mark and arrange disassembly parts in an organized way for easy troubleshooting and assembly.

When loosening nuts and bolts, as a basic rule, start with the one furthest outside, then the one diagonally
opposite, and so on. If the order of loosening is specified, do exactly as specified. Power tools may be
used where noted in the step.
Precautions for Inspection, Repair and ReplacementEBS00IL1
Before repairing or replacing, thoroughly inspect parts. Inspect new replacement parts in the same way, and
replace if necessary.
Precautions for Assembly and InstallationEBS00IL2

Use torque wrench to tighten bolts or nuts to specification.

When tightening nuts and bolts, as a basic rule, equally tighten in several different steps starting with the
ones in center, then ones on inside and outside diagonally in this order. If the order of tightening is speci-
fied, do exactly as specified.

Replace with new gasket, packing, oil seal or O-ring.

Thoroughly wash, clean, and air-blow each part. Carefully check engine oil or engine coolant passages for
any restriction and blockage.

Avoid damaging sliding or mating surfaces. Completely remove foreign materials such as cloth lint or dust.
Before assembly, oil sliding surfaces well.

Release air within route when refilling after draining engine coolant.

Before starting engine, apply fuel pressure to fuel lines with turning ignition switch ON (with engine
stopped). Then make sure that there are no leaks at fuel line connections.

After repairing, start engine and increase engine speed to check engine coolant, fuel, oil, and exhaust
systems for leakage.
Parts Requiring Angular TighteningEBS00IL3

For final tightening of the following engine parts use Tool:
–Cylinder head bolts
–Main bearing cap bolts
–Connecting rod cap bolts
–Crankshaft pulley bolt (No angle wrench is required as the bolt flange is provided with notches for angle
tightening)

Do not use a torque value for final tightening.

The torque value for these parts are for a preliminary step.

Ensure thread and seat surfaces are clean and lightly coated with engine oil. Tool number : KV10112100 (BT-8653-A)

EXHAUST MANIFOLD AND THREE WAY CATALYST
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Tighten the exhaust manifold nuts in the numerical order shown.
Then recheck the torque of the nuts.

Before installing new air fuel ration A/F sensors, clean the exhaust system threads using Tool and apply
anti-seize lubricant.
CAUTION:

Do not over tighten the air fuel ratio A/F sensors. Doing so may cause damage to the sensor,
resulting in the MIL coming on.
KBIA2464E
Tool number : ( — ) J-43879-12
: ( — ) J-43897-18

EM-42Revision: August 2007
TIMING CHAIN
2004 QX56
d. Install bolts in the numerical order shown.
e. Tighten to the specified torque.
CAUTION:
Be sure to wipe off any excessive liquid gasket leaking onto
surface mating with oil pan.
11. Install chain case cover (right bank) and (left bank) as follows:
a. Apply liquid gasket as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-45, "
Recommended Chemical Products and Sealants".
CAUTION:
Both the start and end of application of liquid gasket should
be crossed at an invisible position after attaching the chain
case cover.
b. Install bolts in the numerical order shown.
12. Install the crankshaft pulley.

Install the key of the crankshaft.

Insert the pulley by lightly tapping it.
CAUTION:
Do not tap pulley on the side surface where belt is installed (outer circumference).
13. Tighten the crankshaft pulley bolt.

Lock crankshaft using suitable tool, then tighten the bolt.

Perform the following steps for angular tightening:
a. Apply engine oil onto threaded parts of bolt and seating area.
b. Select one most visible notch of the four on bolt flange. Corre-
sponding to the selected notch, put a mating mark (such as
paint) on crankshaft pulley.
14. Rotate crankshaft pulley in normal direction (clockwise when
viewed from engine front) to check for parts interference.
15. Installation of the remaining components is in the reverse order
of removal.M6 × 50 mm (1.97 in) : No. 1, 20, 25, 26, 27
M6 × 80 mm (3.15 in) : No. 4, 5, 7
M6 × 20 mm (0.79 in) : Except the above
KBIA2478E
KBIA2481E
WBIA0468E
Crankshaft pulley bolt torque
Step 1 : 93.1 N·m (9.5 kg-m, 69 ft-lb)
Step 2 : additional 90° (angle tightening)
KBIA2519E

CAMSHAFT
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INSPECTION AFTER REMOVAL
Camshaft Runout
1. Put V block on precise flat work bench, and support No. 1 and
No. 5 journal of camshaft.
2. Set dial gauge vertically to No. 3 journal.
3. Turn camshaft to one direction with hands, and measure cam-
shaft runout on dial gauge.

1/2 of runout is bend.

If measurement exceeds specification, replace camshaft.
Camshaft Cam Height

Measure camshaft cam height.

If measurement is not within the specifications, replace cam-
shaft.
Camshaft Journal Clearance
Camshaft Journal Diameter

Measure diameter of camshaft journal.
Camshaft Bracket Inner Diameter

Tighten camshaft bracket bolt to specified torque.

Measure inner diameter of camshaft bracket.
Calculation of Camshaft Journal Clearance
(Journal clearance) = (camshaft bracket inner diameter) – (camshaft
journal diameter)

If measurement is not within specification, replace either or both
camshaft and cylinder head.
NOTE:
Inner diameter of camshaft bracket is manufactured together with cylinder head. Replace the whole cylin-
der head assembly.Camshaft runout : Less than 0.02 mm (0.0008 in)
EMK0641D
Standard cam height
(intake & exhaust): 44.465 - 44.655 mm
(1.7506 - 1.7581 in)
Cam wear limit
(intake & exhaust): 0.02 mm (0.0008 in)
PBIC0039E
Standard diameter : 25.953 - 25.970 mm
(1.0218 - 1.0224 in)
PBIC0040E
Standard : 26.000 - 26.021 mm (1.0236 - 1.0244 in)
Standard : 0.030 - 0.068 mm (0.0012 - 0.0027 in)
PBIC1645E