Tonight I opened my power lift gate with the button on the back of the liftgate above the license plate. It opened no problem. But then it wouldn't let me use the power button to close. I had to manually close it. About an hour into my ride home I was getting a high pitch sound coming from the rear of the car. From underneath I nder the bumper there is a box that is making this high pitch squealling sound. It wont stop. I was able to reach up and disconnect the plug on it. Could this be bad? What is it called. Is it a common issue?