CVVT Oil Temperature Sensor (OTS) Description and Operation

Description

The Continuously 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, reduces exhaust emissions (NOx, HC) and improves engine performance by reducing pumping losses, internal EGR effect, improving combustion stability, improving volumetric efficiency and increasing expansion work. This system consists of: - CVVT Oil Control Valve (OCV), which supplies engine oil to the cam phaser or shuts off engine oil from the cam phaser according to the ECM PWM (Pulse Width Modulation) control signal, - CVVT Oil Temperature Sensor (OTS), which measures the engine oil temperature, - and the cam phaser, which changes the camshaft phase using hydraulic pressure of the engine oil. Engine oil flowing from the CVVT oil control valve 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, in the direction of engine rotation or opposite to it.