CVVT Oil Control Valve (OCV) - Description and Operation

Description

The Continuous Variable Valve Timing (CVVT) system advances or retards the intake and exhaust valve timing according to the control signal from the ECM, which is calculated based on engine speed and load. CVVT control provides valve overlap or underlap, which improves fuel economy and reduces exhaust emissions (NOx, HC), and improves engine performance by reducing pumping losses, creating an internal EGR effect, improving combustion stability, improving volumetric efficiency and increasing expansion work. This system consists of the CVVT Oil Control Valve (OCV), which controls the flow of engine oil to and from the cam phaser according to the PWM (Pulse Width Modulation) control signal from the ECM, and the Cam Phaser, which changes camshaft phase using hydraulic pressure from engine oil. Engine oil flowing from the CVVT OCV changes the camshaft phase in the advance direction (intake advance/exhaust retard) or the retard direction (intake retard/exhaust advance) by rotating the rotor connected to the camshaft inside the cam phaser. [Bank 1 / Intake] #1

[Bank 1 / Intake] #2

[Bank 1/Exhaust]