How it works VVT-i toyota

Camshaft timing oil control valve to choose the path to Controller VVT-I according to the amount of current from the engine ECU. VVT-I controller rotates the intake camshaft in accordance with the position where the oil pressure is given, to advance, rewind or holding valve timing. Engine ECU calculates the optimum valve, a variety of operating conditions in accordance with engine speed, intake air volume, throttle position and coolant temperature to control the 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 ecu controls the VVT-i