The vehicle security system has a security code stored in the control system. An identical code is provided by the master key and enables the vehicle to be secured when the key is removed. The improvement provides a facility to programme the system for limited use of the vehicle, e.g. when the vehicle is left in workshop. This allows others to move the vehicle but not to be able to use it for normal travel. The security system can be programmed to give limited use for a preset time and to a maximum speed. In the limited use mode certain parts of the vehicle can remain secured, e.g. glove pocket or luggage space.
