The central locking system will not unlock the tailgate or Right Rear door. I can unlock the Right Rear door from the inside by pulling up the lock button, but their is noting on the inside to open the tailgate. Where do I begin in diagnosing the problem ? Now that the right rear door is open I can pull the door panel to check things out, but how do I get to the tailgate ? Has anyone else had a similar problem with the locking system ? It will be very difficult for Santa to load the sleigh if the tailgate won't open. Any advice and help will be appreciated.