What year? Open the door make sure the interior lights go on then close the door without getting in and see if the lights go off after the time out. If not try to lock the doors with the key fob. If the horn beeps there is a door or hoot open. Better yet look at the display when you get in and see if it says door or hood open. Do the lights ever turn off even when you drive? Also try doing a search for same issue.