I have a 2013 Edge Titanium with a power liftgate. It is supposed to open and close with the push of a button. It does not. It will unlatch, but moves 6 inches and acts like it's hitting something and stops. When closing, it does the same. It moves about 6 inches and stops. I reach up, slowly pull it down, and it closes. Is there a way to disable the power opening and closing without doing damage to something else? I'd like to be able to unlatch it at the button and lift if up and close it manually. Is that an option?