Patent ID: 8818619

Claim:
An apparatus for determining a tire operating condition comprising: a tire-based sensor for sensing tire pressure and temperature and transmitting a signal indicative thereof; a vehicle ignition system; a vehicle-based receiver/controller for receiving the signal from the tire-based sensor and for detecting the state of the vehicle ignition system, said controller providing an error signal when the sensed tire pressure is less than a set threshold value P set and resetting the error signal when the sensed tire pressure is greater than a reset threshold value P rst , the vehicle-based receiver/controller determining the set threshold value P set and the reset threshold value P rst as a function of a calculated warm tire pressure value P warm , determining a mole value N of the tire pressure and adjusting the determined set threshold value P set and the reset threshold value P rst in response to the vehicle ignition state and a change in the determined mole value N; and a display the displaying the error signal from the vehicle-based receiver/controller.