Patent ID: 8542092

Claim:
A vehicle ignition system comprising: a fob including a battery for energizing said fob, a low frequency transceiver having an associated low frequency antenna, and a radio frequency transmitter having an associated radio frequency antenna; an ignition module including a switch, a low frequency transmitter for, when energized, providing a first low frequency signal in a cabin of the vehicle, a low frequency transceiver having an associate low frequency antenna located adjacent the switch for, when energized, proving a second low frequency signal, said second low frequency signal being localized near the switch, and a radio frequency receiver; and a control circuit associated with said ignition module for activating said low frequency transmitter of said ignition module when said switch is activated to provide said first low frequency signal in the cabin of the vehicle and monitoring for a radio frequency response signal from said fob using said radio frequency receiver, said control circuit, upon an absence of monitoring the radio frequency response signal from said fob, activating said low frequency transceiver of said ignition module to provide said second low frequency signal from the associated antenna located adjacent the switch and, after providing said second low frequency signal, monitoring for a low frequency response signal from said fob, said second low frequency signal from said low frequency transceiver providing operating energy for said fob when said fob is located sufficiently near said switch, said fob providing the radio frequency response signal in response to receiving the first low frequency signal from the ignition module when the battery of said fob is energizing said fob and providing the low frequency response signal in response to receiving and being energized by the second low frequency signal from said low frequency transceiver of said ignition module when the battery fails to energize said fob, said control circuit further including a verification device to verify that said fob is a fob associated with that vehicle based on at least one of the radio frequency response signal and the low frequency response signal from the fob.