Oil Pressure Regulation
The main component of the oil pressure control is a vane pump driven by the crankshaft with a chain. The pump has an adjustable outer ring. Displacement of the pump changes depending on the position of the outer ring. In its original position the pump gives its maximum flow and thus maximum oil pressure, while when fully regulated gives a smaller flow/pressure.
Depending on the engine temperature, engine speed (RPM) and torque output the oil pump is controlled to a current optimal pressure. Thereby, the power consumption from the oil pump can decrease, which eventually contributes to a reduction of fuel consumption and exhaust emissions.
The regulation of displacement is performed by a control valve that is located on the oil pump housing. By controlling the flow of oil the adjustment ring can be rotated, changing the eccentricity and thus the vane pump's supply volume.
Unpowered control valve means that the adjustment ring is return sprung to the position where the pump produces maximum oil pressure.
The Engine Control Module uses the information from the engine oil pressure and engine temperature sensor to calculate the control signal to the control valve to achieve the desired oil pressure.