Variable Valve Timing Actuator: Description and Operation

CIRCUIT DESCRIPTION

VVT system controls the intake valve timing to proper timing in response to driving condition. ECM controls Oil Control Valve (OCV) to make the intake valve timing properly, and oil pressure controlled with OCV is supplied to the VVT controller, and then VVT controller changes relative position between the camshaft and the crankshaft.

VVT sensor (VVL or VVR signal) consist of a signal plate and pickup coil.
The VVL or VVR signal plate has 1 tooth on its outer circumference and is mounted on the intake camshafts. When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change, causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil. The actual camshaft angle is detected by the VVT sensor and it provides feedback to the ECM to control the intake valve timing in response to during condition.