Engine ECU calculates the optimum valve under various operating conditions in accordance with engine speed, intake air volume, throttle position and coolant temperature to control the OCV (oil control valve camshaft timing). In addition, the engine ECU uses signals from the camshaft position sensor and crankshaft position sensor to calculate the actual valve timing, and executes the feedback control valve timing to achieve the target.how the VVT-i at low speed, medium and high
