Variable Force Solenoid (VFS)

Description and Operation

Description

The Continuously Variable Valve Timing (CVVT) system advances or retards the valve timing of the intake and exhaust valves in accordance with the control signal from the ECM, which is calculated based on engine speed and load. By controlling CVVT, valve overlap or underlap is achieved, which improves fuel economy, reduces exhaust emissions (NOx, HC), and improves engine performance by reducing pumping losses, providing an internal exhaust gas recirculation effect, improving combustion stability, improving volumetric efficiency, and increasing expansion work. This system consists of a Variable Force Solenoid (VFS), which supplies engine oil to the cam phaser or shuts off the oil from the cam phaser according to the ECM PWM (Pulse Width Modulation) signal, and a cam phaser, which changes the camshaft phase using hydraulic pressure from the engine oil. The Variable Force Solenoid (VFS) [Intake] changes its force depending on the PWM duty to control the valve stroke of the CVVT Oil Control Valve (OCV) [Intake] bolt. The supplied oil rotates the rotor connected to the camshaft of the cam phaser and turns the camshaft in the direction of engine rotation (intake advance/exhaust retard) or in the opposite direction (intake retard/exhaust advance) to change the camshaft phase angle.

Variable Force Solenoid (VFS) [Bank 1 / Intake]

Circuit Diagrams

Wiring Diagram

Harness Connector

Repair Procedures

Removal

1. 1

   Turn the ignition switch OFF and disconnect the negative (-) battery terminal.

2. 2

   Disconnect the VFS connector (A).

3. 3

   Remove the mounting bolts (B) and remove the VFS from the engine.

   Variable Force Solenoid mounting bolt:

   9,8–11.8 N·m

   

Installation

1. Install in the reverse order of removal.