Could be a tricky problem to solve. The whole think involves several computers (Engine, Body Control, Door control and EVIC) communicating on a data network. The body control module instructs the door module to lock the doors if the rolling lock function is enabled and the engine controller says the Jeep has got up to speed. Unless there is another problem with the central locking, I can't really suggest what to do unless you happen to have a DRBIII scan tool to hand.