Keyless device for controlling access to automobiles and keyless method for checking access authorization

A keyless device for controlling access to a motor vehicle, the device comprising:

• a transceiver device in a motor vehicle, the transceiver device having a plurality of transmitters for transmitting respective code signals, the transceiver device further having a transceiver unit for transmitting a key interrogation signal and for receiving a response signal and a crypto-code signal;
• and
• a mobile transponder having a receiver for receiving the code signals and the key interrogation signal, the transponder further having a transmitter for transmitting a response signal and a crypto-code signal;
• wherein upon the receiver of the transponder receiving a code signal from a respective transmitter of the transceiver device the transmitter of the transponder transmits a response signal indicative of the respective transmitter of the transceiver device to the transceiver unit of the transceiver device, and wherein upon the receiver of the transponder receiving a key interrogation signal from the transceiver unit of the transceiver device the transmitter of the transponder transmits a crypto-code signal to the transceiver unit of the transceiver device;
• wherein upon the transceiver unit of the transceiver device receiving a crypto-code signal from the transmitter of the transponder the transceiver device checks the crypto-code signal to determine motor vehicle access authorization of the transponder;
• wherein the transceiver device actuates a motor vehicle access function associated with the respective transmitter of the transceiver device upon determining that the transponder has proper motor vehicle access authorization.

A keyless method for checking access authorization in motor vehicles, the method comprising:

• transmitting respective code signals from a plurality of transmitters of a transceiver device in a motor vehicle;
• transmitting a key interrogation signal from a transceiver unit of the transceiver device;
• receiving the code signals with a receiver of a mobile transponder;
• receiving the key interrogation signal with the receiver of the mobile transponder;
• transmitting a response signal from a transmitter of the mobile transponder upon the receiver of the transponder receiving a code signal from a respective transmitter of the transceiver device, the response signal indicative of the respective transmitter of the transceiver device;
• transmitting a crypto-code signal from the transmitter of the transponder upon the receiver of the transponder receiving a key interrogation signal from the transceiver unit of the transceiver device;
• receiving the response signal and the crypto-code signal with the transceiver unit of the transceiver device;
• checking the crypto-code signal to determine motor vehicle access authorization of the transponder with the transceiver device upon the transceiver unit of the transceiver device receiving a crypto-code signal from the transmitter of the transponder;
• and
• actuating a motor vehicle access function associated with the respective transmitter of the transceiver device using the transceiver device upon the transceiver device determining that the transponder has proper motor vehicle access authorization.