Oil Pump Solenoid Valve
Variable Oil Pump is a system to improve fuel efficiency by optimizing engine oil pressure with controlling it as two modes (low/high) according to engine RPM.
Oil pressure regulating valve turns ON in low pressure mode. Discharge rate of engine oil is decreased as bypassed oil lifting up rotor. It makes pressure of engine oil decreased.
Fuel efficiency is improved as engine load to rotate oil pump pulley reduced.
Mode change depends on engine RPM, oil temperature, and engine load.