Patent ID: 7245210

Claim:
An electronic key system for a vehicle, including a transmission antenna, a controller connected to the transmission antenna and a portable transceiver for transmitting ID data based on a request signal transmitted from the controller through the transmission antenna, wherein the controller receives the ID data through a receiving antenna, the electronic key system for a vehicle further comprising: first means which outputs a first request signal to the portable transceiver based on activation of the controller; second means which outputs a second request signal to the portable transceiver following the first request signal, and in response to an ON operation of a start switch for the vehicle; third means for detecting the ID data from the portable transceiver based on the request signal; and fourth means for warning an operator when the ID data is not received from the portable transceiver, even though the first request signal has been outputted from the first means and warning the operator when the ID data is not received from the portable transceiver, even though the second request signal has been outputted from or the second means, wherein when the ID data is detected in response to the first request signal, the controller allows power to be supplied to electrical component drive circuits, and wherein when the ID data is detected in response to the second request signal, the controller allows power to be supplied to the vehicle such that vehicle travel is possible.