INFINITI QX56 2011 Factory Service Manual

COMPONENT PARTSEC-17
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EXHAUST COMPARTMENT
1. VVEL actuator motor (bank 2) 2. Ignition coil (with power transistor)
and spark plug (bank 2)3. Camshaft position sensor (bank 2)
4. High pressure fuel pump 5. Intake valve timing control solenoid valve (bank 2)6. Electric-viscous fan assembly
7. Engine oil temperature sensor 8. Intake valve timing control solenoid valve (bank 1)9. Camshaft position sensor (bank 1)
10. Ignition coil (with power transistor) and spark plug (bank 1) 11. VVEL actuator motor (bank 1) 12. Low fuel pressure sensor
13. Positive crankcase ventilation (PCV) valve 14. Fuel injector (bank 2) 15. Knock sensor (bank 2)
16. Knock sensor (bank 1) 17. Fuel injector (bank 1) 18. Fuel rail pressure sensor
19. Manifold absolute pressure sensor 20. VVEL control shaft position sensor (bank 1)21. Crankshaft position sensor
22. Engine coolant temperature sensor 23. VVEL control shaft position sensor (bank 2)
A. Top view of the engine (View with intake manifold is re-
moved) B. Rear view of the engine
:Engine front
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COMPONENT PARTS
BODY COMPARTMENT
1. A/F sensor 1 (bank 2) 2. A/F sensor 1 (bank 1) 3. Heated oxygen sensor 2 (bank 1)
4. Heated oxygen sensor 2 (bank 2)
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COMPONENT PARTSEC-19
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Component DescriptionINFOID:0000000006217657
1. ASCD steering switch
ICC steering switch 2. Snow mode switch 3. Fuel level sensor unit and fuel pump
assembly (with fuel tank temperature
sensor)
4. Fuel pump control module (FPCM) 5. EVAP canister vent control valve 6. EVAP canister
7. EVAP control system pressure sen- sor 8. Stop lamp switch 9. ASCD brake switch
ICC brake switch
10. Accelerator pedal position sensor
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Component Reference
ECM EC-23, "
ECM"
Malfunction indicator lamp (MIL)EC-30, "Malfunction Indicator Lamp (MIL)"
Ignition coil with power transistorEC-29, "Ignition Coil With Power Transistor"
Accelerator pedal position sensorEC-21, "Accelerator Pedal Position Sensor"
Mass air flow sensor
EC-31, "Mass Air Flow Sensor (With Intake Air Temperature Sen-
sor)"Intake air temperature sensor
Electric throttle control actuator
EC-23, "
Electric Throttle Control Actuator"Throttle control motor relay
Throttle control motor
Throttle position sensor
Crankshaft position sensorEC-23, "
Crankshaft Position Sensor"
Camshaft position sensorEC-22, "Camshaft Position Sensor"
Engine coolant temperature sensorEC-25, "Engine Coolant Temperature Sensor"
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COMPONENT PARTS
High pressure fuel pump
EC-28, "High Pressure Fuel Pump"
Low pressure fuel pumpEC-30, "Low Pressure Fuel Pump"
Fuel pump control module (FPCM)EC-27, "Fuel Pump Control Module"
Fuel rail pressure sensorEC-27, "Fuel Rail Pressure Sensor"
Low fuel pressure sensorEC-30, "Low Fuel Pressure Sensor"
Fuel injectorEC-26, "Fuel Injector"
Fuel level sensorEC-26, "Fuel Level Sensor"
Fuel tank temperature sensorEC-27, "Fuel Tank Temperature Sensor"
A/F sensor 1
EC-21, "Air Fuel Ratio (A/F) Sensor 1"A/F sensor 1 heater
Heated oxygen sensor 2EC-27, "
Heated Oxygen Sensor 2"Heated oxygen sensor 2 heater
Manifold absolute pressure sensorEC-31, "
Manifold Absolute Pressure Sensor"
Knock sensorEC-30, "Knock Sensor"
Engine oil temperature sensorEC-25, "Engine Oil Temperature Sensor"
Power steering pressure sensorEC-31, "Power Steering Pressure (PSP) Sensor"
Electrically-controlled cooling fan coupling EC-24, "Electrically-controlled cooling fan coupling"
Intake valve timing control solenoid valveEC-29, "Intake Valve Timing Control Solenoid Valve"
VVEL control moduleEC-32, "VVEL Control Module"
VVEL actuator motor relayEC-32, "VVEL Actuator Motor Relay"
VVEL actuator motorEC-32, "VVEL Actuator Motor"
VVEL control shaft position sensor EC-32, "VVEL Control Shaft Position Sensor"
EVAP control system pressure sensor EC-26, "EVAP Control System Pressure Sensor"
EVAP canister vent control valveEC-26, "EVAP Canister Vent Control Valve"
EVAP canister purge volume control solenoid valveEC-26, "EVAP Canister Purge Volume Control Solenoid Valve"
Battery current sensor (with battery temperature sensor)EC-22, "Battery Current Sensor (With Battery Temperature Sen-
sor)"
Refrigerant pressure sensor
EC-32, "Refrigerant Pressure Sensor"
Stop lamp switch
EC-21, "ASCD Brake Switch & Stop Lamp Switch"ASCD brake switch
ASCD steering switchEC-21, "
ASCD Steering Switch"
Information displayEC-49, "AUTMATIC SPEED CONTROL DEVICE (ASCD) : Switch
Name and Function"
Stop lamp switch
EC-29, "ICC Brake Switch & Stop Lamp Switch"ICC brake switch
ICC steering switchEC-29, "
ICC Steering Switch"
Component Reference
Revision: 2010 May2011 QX56

COMPONENT PARTSEC-21
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Accelerator Pedal
Position SensorINFOID:0000000006217658
The accelerator pedal position (APP) sensor is installed on the
accelerator pedal assembly. The sensor detects the accelerator
position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometer which transform the accelerator pedal
position into output voltage, and emit the voltage signals to the ECM.
The ECM judges the current opening angle of the accelerator pedal
from these signals and controls the throttle control motor based on
these signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The
ECM uses this signal for engine operations such as fuel cut.
Air Fuel Ratio (A/F) Sensor 1INFOID:0000000006217659
DESCRIPTION
The sensor element of the A/F sensor 1 is composed an electrode layer, which transports ions. It has a heater
in the element.
The sensor is capable of precise measurement = 1, but also in the lean and rich range. Together with its
control electronics, the sens or outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at the sensor cell. An electrode layer is
applied voltage, and this current relative oxygen density in lean. Also this current relative hydrocarbon density
in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of approxi-
mately 760 °C (1,400 °F).
A/F SENSOR 1 HEATER
A/F sensor 1 heater is integrated in the sensor.
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F s ensor 1 element within the specified range.
ASCD Brake Switch & Stop Lamp Switch INFOID:0000000006217660
Stop lamp switch and ASCD brake switch are installed to brake pedal bracket.
When the brake pedal is depressed, ASCD brake switch is turned OFF and stop lamp switch is turned ON.
ECM detects the state of the brake pedal by those two types of input (ON/OFF signal).
ASCD Steering SwitchINFOID:0000000006217661
ASCD steering switch has variant values of electrical resistance for each button. ECM reads voltage variation
of switch, and determines which button is operated.
ASCD IndicatorsINFOID:0000000006217662
ASCD operation status is indicated by CRUISE indicator in combination meter.
ECM transmits the ASCD status signal to the combi nation meter via CAN communication according to ASCD
operation.
PBIB1741E
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COMPONENT PARTS
Battery Current Sensor (With Battery Temperature Sensor)
INFOID:0000000006217663
OUTLINE
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator.
Based on sensor signals, ECM judges whether or not the power
generation voltage variable control is performed. When performing
the power generation voltage variable control, ECM calculates the
target power generation voltage based on the sensor signal. And
ECM sends the calculated value as the power generation command
value to IPDM E/R. For the details of the power generation voltage
variable control, refer to CHG-7, "
POWER GENERATION VOLTAGE
VARIABLE CONTROL SYSTEM : System Description".
CAUTION:
Never connect the electrical component or the groun d wire directly to the battery terminal. The con-
nection causes the malfunction of th e power generation voltage variable control, and then the battery
discharge may occur.
BATTERY CURRENT SENSOR
The battery current sensor is installed to the battery cable at the negative terminal. The sensor measures the
charging/discharging current of the battery.
BATTERY TEMPERATURE SENSOR
Battery temperature sensor is int egrated in battery current sensor.
The sensor measures ambient temperature around the battery.
The electrical resistance of the t hermistor decreases as temperature
increases.

*: These data are reference values and are measured between ECM terminals.
Camshaft Position SensorINFOID:0000000006217664
The camshaft position (CMP) sensor senses the protrusion of the
signal plate installed to the camshaft (INT) front end to identify a par-
ticular cylinder. The camshaft position sensor senses the piston posi-
tion.
The sensor consists of a permanent magnet and Hall IC.
When engine is running, the high and low parts of the teeth cause
the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
When the crankshaft position sens or system becomes inoperative,
the camshaft position sensor provides various controls of engine parts instead, utilizing timing of cylinder iden-
tification signals.
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Temperature [ °C ( °F)] Voltage* (V) Resistance (k Ω)
25 (77) 3.333 1.9 - 2.1
90 (194) 0.969 0.222 - 0.258
SEF012P
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COMPONENT PARTSEC-23
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ECM receives the signals as shown in the figure.
Crankshaft Position SensorINFOID:0000000006217665
The crankshaft position (CKP) sensor senses the protrusion of the
signal plate installed to the drive plate to identify fluctuation of the
engine revolution.
The sensor consists of a permanent magnet and Hall IC.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic fiel
d, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM receives the signals as shown in the figure.
ECMINFOID:0000000006217666
 ECM (Engine Control Module) controls the engine.
 The ECM consists of a microcomputer and connectors for trans- mitting/receiving signals and for supplying power. Furthermore, the
ECM is equipped with an injector dr iver unit and actuates the fuel
injector at a high voltage (approximately 70 V at the maximum).
 ECM is equipped with ECM temperature sensors. If ECM is over- heated, ECM controls output torque to prevent damage to itself.
 Battery voltage is supplied to the ECM even when the ignition
switch is turned OFF for the ECM memory function of the DTC
memory, the air-fuel ratio feedback compensation value memory,
the idle air volume learning value memory, etc.
Electric Throttle Control ActuatorINFOID:0000000006217667
OUTLINE
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COMPONENT PARTS
Electric throttle control actuator consists of throttle bod
y, throttle valve, throttle control motor and throttle posi-
tion sensor.
THROTTLE CONTROL MOTOR
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor. The throttle position
sensor provides feedback to the ECM, when opens/closes the throttle valve in response to driving conditions
via the throttle control motor.
THROTTLE POSITION SENSOR
The throttle position (TP) sensor responds to the throttle valve move-
ment.
The throttle position sensor has two sensors. These sensors are a
kind of potentiometer which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and controls the throttle valve opening angle in response to
driving conditions via the throttle control motor.
Electrically-controlled cooling fan couplingINFOID:0000000006217668
Electrically-controlled cooling fan coupling is integrat ed with a fan coupling, fan coupling driver, and fan speed
sensor, mounted to the fan pulley, and actuated by the dr ive belt to rotate the cooling fan at a speed suitable
for a driving condition.
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PBIB0145E
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COMPONENT PARTSEC-25
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OEngine Coolant Temperature SensorINFOID:0000000006217669
The engine coolant temperature (ECT
) sensor is used to detect the
engine coolant temperature. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the engine
coolant temperature input. The sens or uses a thermistor which is
sensitive to the change in temperature. The electrical resistance of
the thermistor decreases as temperature increases.

*: These data are reference values and are measured between ECM terminals.
Engine Oil Temperature SensorINFOID:0000000006217670
The engine oil temperature sensor is used to detect the engine oil
temperature. The sensor modifies a voltage signal from the ECM.
The modified signal returns to the ECM as the engine oil tempera-
ture input. The sensor uses a ther mistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

*: These data are reference values and are measured between ECM terminals. 1. Valve 2. Armature 3. Magnet Loop Element
4. Fan speed sensor 5. Coil 6. Silicon oil
SEF594K
Engine coolant temperature
[° C ( °F)] Voltage* (V) Resistance (k
Ω)
− 10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.35 - 2.73
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
SEF594K
Engine oil temperature [° C ( °F)] Voltage* (V) Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.35 - 2.73
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
110 (230) 0.6 0.143 - 0.153
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COMPONENT PARTS
EVAP Control System Pressure Sensor
INFOID:0000000006256476
The EVAP control system pressure s ensor detects pressure in the
purge line. The sensor output voltage to the ECM increases as pres-
sure increases.
EVAP Canister Vent Control ValveINFOID:0000000006256477
The EVAP canister vent control valve is located on the EVAP canis-
ter and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evaporative
emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the evapo-
rative emission control system is depressurized and allows “EVAP
Control System” diagnosis.
EVAP Canister Purge Volume Control Solenoid ValveINFOID:0000000006217671
The EVAP canister purge volume control solenoid valve is used to
control the flow rate of fuel vapor from the EVAP canister. 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.
Fuel InjectorINFOID:0000000006217672
For the fuel injector, a high pressure fuel injector is used and this
enables a high-pressure fuel injection at a high voltage within a short
time. The ECM is equipped with an injector driver unit and actuates
the fuel injector at a high volt age (approximately 65 V at the maxi-
mum).
Fuel Level SensorINFOID:0000000006217673
The fuel level sensor is mounted in the fuel level sensor unit.
PBIB3370E
PBIB1263E
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Revision: 2010 May2011 QX56