My car's oil light has been flashing off and on today. Oil is full, however on 2002 Toyota Camry

I took the car to our local Advance Auto Parts and an employee checked it out with his analyzing machine and he said the oil sending unit might need to be replaced. At home, we checked again and it checked fine with our machine. (the Car MD) My family think's only the oil check light may be bad and only it needs to be replaced. Could you tell me what needs to be done and what the estimated costs will be. Thank you very much. This problem just started.

Asked by for the 2002 Toyota Camry
Have your oil pressure checked professionally.The light is blinking on and off because of LOW oil PRESSURE not the amount of oil in your engine.Advance doesn't diagnose.....they sell parts , that includes engines once yours is toast. If I'm correct the oil light flashes primarily when at idle and is off when your driving (or above 1200 RPMs?That means there is a different problem , which could be as simple as changing the oil, putting in a GOOD grade of 10W30 and a TOYOTA filter (their filters are designed different and will work better than others in your car.