Nissan Frontier. Manual - part 483

TUMBLE CONTROL VALVE CONTROL

EC-503

< SYSTEM DESCRIPTION >

[VQ40DE FOR USA AND CANADA]

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TUMBLE CONTROL VALVE CONTROL

System Description

INFOID:0000000009481202

SYSTEM DIAGRAM

SYSTEM DESCRIPTION

Intake manifold runner control valve has a valve portion in the intake passage of each cylinder.

While idling and during low engine coolant temperature, the intake manifold runner control valve closes. Thus

the velocity of the air in the intake passage increases, promoting the vaporization of the fuel and producing a

intake manifold runner in the combustion chamber.

Because of this operation, this system tends to increase the burning speed of the gas mixture, improve

exhaust emission, and increase the stability in running conditions.

Also, except when idling and during low engine coolant temperature, this system opens the intake manifold

runner control valve.

In this condition, this system tends to increase power by improving intake efficiency via reduction of intake flow

resistance.

The intake manifold runner control valve is operated by the ECM.

JPBIA6226GB

EC-504

< SYSTEM DESCRIPTION >

[VQ40DE FOR USA AND CANADA]

VARIABLE INDUCTION AIR SYSTEM

VARIABLE INDUCTION AIR SYSTEM

Description

INFOID:0000000009481203

SYSTEM DESCRIPTION

*: ECM determines the start signal status by the signals of engine speed and battery voltage.

When the engine is running at medium speed, the ECM sends the ON signal to the VIAS control solenoid

valve. This signal introduces the intake manifold vacuum into the power valve actuator and therefore closes

the power valve.

Under this condition, the effective intake manifold length is equivalent to the total length of passage A and pas-

sage B. This long intake manifold provides increased amount of intake air, which results in improved suction

efficiency and higher torque.

When engine is running at low or high speed, the ECM sends the OFF signal to the VIAS control solenoid

valve and the power valve is opened.

Under this condition, the effective intake manifold length is equivalent to the length of passage B. This short-

ened intake manifold length results in enhanced engine output due to reduced suction resistance under high

speeds.

COMPONENT DESCRIPTION

Power Valve

Sensor

Input Signal to ECM

ECM function

Actuator

Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)

Engine speed*

VIAS control

VIAS control solenoid valve

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

Battery

Battery voltage*

PBIB1822E

VARIABLE INDUCTION AIR SYSTEM

EC-505

< SYSTEM DESCRIPTION >

[VQ40DE FOR USA AND CANADA]

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The power valve is installed in intake manifold collector and used to

control the suction passage of the variable induction air control sys-

tem. It is set in the fully closed or fully opened position by the power

valve actuator operated by the vacuum saved in the surge tank. The

vacuum in the surge tank is controlled by the VIAS control solenoid

valve.

VIAS Control Solenoid Valve

The VIAS control solenoid valve cuts the intake manifold vacuum

signal for power valve control. It responds to ON/OFF signals from

the ECM. When the solenoid is off, the vacuum signal from the

intake manifold is cut. When the ECM sends an ON signal the coil

pulls the plunger downward and feeds the vacuum signal to the

power valve actuator.

BBIA0569E

BBIA0569E

EC-506

< SYSTEM DESCRIPTION >

[VQ40DE FOR USA AND CANADA]

VARIABLE INDUCTION AIR SYSTEM

Vacuum Hose Drawing

INFOID:0000000009481204

Refer to 

EC-479, "System Diagram"

 for Vacuum Control System.

PBIB2529E