Something to consider: I had battled the same issue a while back and replaced the sensor only to find the same fault showing for low oil level. It's not always the sensor. The wires for this sensor run down in front and along the oil pan. The wire wrap is almost always disintegrated from oil leaks and the wires rub and fray on the pan and the chassis reinforcing plate. As was my case, inspect those wires for a ground short too.