You could try resetting the system by removing the fuse that feed the central locking. I know that this is one of the usual cures on a Ford ( which thae main dealer will not tell you about + charge you £80 plus VAT for doing so !) If you can`t find the fuse, then remove the battery lead but MAKE SURE THAT YOU HAVE THE RADIO CODE before doing so.
RedRooster
May 2008