A solenoid operated unit (100) for detecting and removing an undesired fluid (6) from a desired fluid (5) with diagnostic metering, comprises a unified solenoid operated pump and valve unit (70), a drainage path (40), an electrical detection system (60), a mecha-electro-magnetic detection system (80) and a junction box (190) interacting with an electronic control unit (90) comprising a PWM generator. A plunger (50) moves from up to down, a sweeping volume (28) with a cycle of a PWM electricity wave, while moving down the plunger (50) creates a negative pressure in a sweeping volume (28) and while moving up a positive pressure gets created in the sweeping volume (28) and a negative pressure gets created at a rear end (30) of a unified chamber (26), an air reliever (180) is provided for breathing.