While driving down the road recently my doors locked themselves and triggered the alarm. The car drove normally otherwise, but it was obviously very embarrassing...I felt like I was stealing my own car. I later tried locking the doors right after starting the car and all was well. Everything is still ok unless I forget to lock the doors manually. If I don't...alarm again. Could this simply be the door lock vacuum pump. If so, where is it located and how troublesome to replace? Thanks in advance...Bill