Infiniti QX56 (Z62). Manual - part 512

EC-26

< SYSTEM DESCRIPTION >

[VK56VD]

COMPONENT PARTS

EVAP Control System Pressure Sensor

INFOID:0000000006256476

The EVAP control system pressure sensor detects pressure in the
purge line. The sensor output voltage to the ECM increases as pres-
sure increases.

EVAP Canister Vent Control Valve

INFOID: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 Valve

INFOID: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 Injector

INFOID: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 voltage (approximately 65 V at the maxi-
mum).

Fuel Level Sensor

INFOID:0000000006217673

The fuel level sensor is mounted in the fuel level sensor unit.

PBIB3370E

PBIB1263E

JMBIA0069ZZ

JSBIA0287ZZ

COMPONENT PARTS

EC-27

< SYSTEM DESCRIPTION >

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The sensor detects a fuel level in the fuel tank and transmits 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 other is variable resistor. Fuel level sensor output volt-
age changes depending on the movement of the fuel mechanical float.

Fuel Pump Control Module

INFOID:0000000006217674

The fuel pump control module (FPCM) controls the discharging vol-
ume of the fuel pump by transmitting the FPCM control signals (Low/
Mid/High) depending on driving conditions.

Fuel Rail Pressure Sensor

INFOID: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 Sensor

INFOID: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 thermistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.
<Reference data>

*: These data are reference values and are measured between ECM terminals.

Heated Oxygen Sensor 2

INFOID:0000000006217677

DESCRIPTION

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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

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 controlled 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 oxygen 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 oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature. 

High Pressure Fuel Pump

INFOID: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 solenoid 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

COMPONENT PARTS

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Operating Chart

ICC Brake Switch & Stop Lamp Switch

INFOID:0000000006217679

Stop lamp switch and ICC brake switch are installed to brake pedal bracket.
When the brake pedal is depressed, ICC 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).
ECM transmits ICC brake switch signal to ADAS control unit via CAN communication line.

ICC Steering Switch

INFOID:0000000006217680

ICC steering switch has variant values of electrical resistance for each button. ECM reads voltage variation of
switch, and determines which button is operated.
ECM transmits ICC steering switch signal to ADAS control unit via CAN communication line.

Ignition Coil With Power Transistor

INFOID:0000000006217681

The ignition signal from the ECM is sent to and amplified by the
power transistor. The power transistor turns ON and OFF the ignition
coil primary circuit. This ON/OFF operation induces the proper high
voltage in the coil secondary circuit.

Intake Valve Timing Control Solenoid Valve

INFOID:0000000006217682

Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing control solenoid valve changes the oil
amount and direction of flow through intake valve timing control unit
or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.

JSBIA0286GB

PBID0206J

PBIB1842E