A remote wireless keyless entry transmitter includes a communications interface for connecting the transmitter directly to an in-vehicle network for registering the transmitter with the vehicle access system. The interface is further connectable to a personal computer to load a set of control codes and programming codes corresponding to a vehicle. The transmitter is programmable to operate multiple functions for multiple vehicles, separately or simultaneously. The transmitter can include a transponder circuit, a display, an accelerometer and a key coupler. A wireless transponder is operationally associated with a vehicle security system by physically connecting the transponder to a vehicle data port with a temporary data link and transferring data between the security system and the transponder over the data link to enable subsequent wireless operation of the security system with the transponder. The transmitter can include an audible signal generator and be programmable to respond to a pager signal.