EXTENSION FUNCTION CODE GENERATING METHOD IN KEYLESS ENTRY SYSTEM FOR VEHICLE, AND ITS DEVICE

PROBLEM TO BE SOLVED: To provide an extension function code generating method in a keyless entry system for vehicles capable of generating a large number of new command codes, and its device by providing an additional function extension switch to a transmission device for a conventional keyless entry system, and changing the control software. SOLUTION: A transmission device 1 in this keyless entry system for vehicles comprises a door lock switch SW1, a door unlock switch SW2, a function extension switch F-SW, a control part 5 to receive the input of each switch, a storage part 7 to store a plurality of kinds of codes to be transmitted by the transmission device 1, and a transmission part 9 to transmit the code selected by the control part 5 out of the codes stored in the storage part 7 to a vehicle. When the function extension switch F-SW is operated, the mode is shifted to the function extension mode, and when the door lock switch SW1 or the door unlock switch SW2 is operated, an extension function code which is neither the door lock code nor the door unlock code is generated.