2011 INFINITI QX56 sensor

EC-22
< SYSTEM DESCRIPTION >[VK56VD]
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.
JPBIA3262ZZ
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
JMBIA0064ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSEC-23
< SYSTEM DESCRIPTION > [VK56VD]
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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
JMBIA1559GB
JMBIA0062ZZ
JMBIA1559GB
JMBIA0057ZZ
Revision: 2010 May2011 QX56

EC-24
< SYSTEM DESCRIPTION >[VK56VD]
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.
JSBIA0270GB
PBIB0145E
JSBIA0289ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSEC-25
< SYSTEM DESCRIPTION > [VK56VD]
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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
SEF012P
Revision: 2010 May2011 QX56

EC-26
< SYSTEM DESCRIPTION >[VK56VD]
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
JMBIA0069ZZ
JSBIA0287ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSEC-27
< SYSTEM DESCRIPTION > [VK56VD]
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The sensor detects a fuel level in the fuel tank and tr
ansmits a signal to the combination meter. The combina-
tion meter sends the fuel level sensor signal to the ECM via the CAN communication line.
It consists of two parts, one is mechanical float and the ot her is variable resistor. Fuel level sensor output volt-
age changes depending on the movement of the fuel mechanical float.
Fuel Pump Control ModuleINFOID:0000000006217674
The fuel pump control module (FPCM) controls the discharging vol-
ume of the fuel pump by transmitt ing the FPCM control signals (Low/
Mid/High) depending on driving conditions.
Fuel Rail Pressure SensorINFOID:0000000006217675
The fuel rail pressure (FRP) sensor is placed to the fuel rail and
measures fuel pressure in the fuel rail. The sensor transmits voltage
signal to the ECM. As the pressure increases, the voltage rises. The
ECM controls the fuel pressure in the fuel rail by operating high pres-
sure fuel pump. The ECM uses the signal from fuel rail pressure sen-
sor as a feedback signal.
Fuel Tank Temperature SensorINFOID:0000000006217676
The fuel tank temperature sensor is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature 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.
Heated Oxygen Sensor 2INFOID:0000000006217677
DESCRIPTION
NNBIB0006ZZ
JSBIA0291ZZ
Fuel temperature [ °C ( °F)] Voltage* (V) Resistance (k Ω)
20 (68) 3.5 2.3 - 2.7
50 (122) 2.2 0.79 - 0.90
SEF012P
Revision: 2010 May2011 QX56

EC-28
< SYSTEM DESCRIPTION >[VK56VD]
COMPONENT PARTS
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of
the air fuel ratio (A/F) sensor 1
are shifted, the air fuel ratio is c ontrolled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1 V in richer conditions to 0 V in leaner con-
ditions.
Under normal conditions the heated ox ygen sensor 2 is not used for
engine control operation.
HEATED OXYGEN SENSOR 2 HEATER
Heated oxygen sensor 2 heater is integrated in the sensor.
The ECM performs ON/OFF control of the heated oxy gen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
High Pressure Fuel PumpINFOID:0000000006217678
The high pressure fuel pump is installed at the front of the engine bank 2 side and activated by the camshaft.
ECM controls the high pressure fuel pump control sol enoid valve built into the high pressure fuel pump and
adjusts the amount of discharge by changing the suction timing of the low pressure fuel.
Operating Description
SEF327R
Engine speed Heated oxygen sensor 2 heater
Above 3,600 rpm OFF
Below 3,600 rpm after the following conditions are met.
 Engine: After warming up
 Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and at idle for 1 minute under no load ON
JSBIA0285GB
Revision: 2010 May2011 QX56

EC-30
< SYSTEM DESCRIPTION >[VK56VD]
COMPONENT PARTS
Knock Sensor
INFOID:0000000006217683
The knock sensor is attached to t he cylinder block. It senses engine
knocking using a piezoelectric element. A knocking vibration from
the cylinder block is sensed as vibrational pressure. This pressure is
converted into a voltage signal and sent to the ECM.
Low Fuel Pressure SensorINFOID:0000000006217684
The low fuel pressure sensor is installed to low fuel pressure piping
and measures the low fuel pressu re. The sensor transmits voltage
signal to the ECM. As the pressure increases, the voltage rises.
Low Pressure Fuel PumpINFOID:0000000006217685
The low pressure fuel pump is integrated with a fuel pressure regula-
tor and a fuel filter. This pump is build into the fuel tank.
ECM controls the low pressure fuel pump via FPCM.
Malfunction Indicator Lamp (MIL)INFOID:0000000006217686
The Malfunction Indicator Lamp (MIL) is located on the combination
meter.
The MIL will illuminate when the ignition switch is turned ON without
the engine running. This is a bulb check.
When the engine is started, the MIL should turn off. If the MIL
remains illuminated, the on board diagnostic system has detected an
engine system malfunction.
For details, refer to EC-51, "
Diagnosis Description".
JSBIA0284ZZ
JSBIA0292ZZ
JPBIA3235ZZ
SEF217U
Revision: 2010 May2011 QX56