An apparatus (10) determines a tire condition and location on a vehicle (12) including a tire-based sensing unit (14), a plurality of tires (54) on the vehicle having an associated tire-based sensing unit, each tire-based sensing unit (14) including, a first
tire rotation sensor (66) mounted for rotation with the tire (54) and for providing a first
tire rotation signal (80) each time the tire passes one of at least two predetermined rotational positions during
tire rotation, a tire condition sensor (82) for sensing a tire condition and for providing a tire condition
signal indicative thereof and an unique tire identification indicator, a
transmitter (86) for transmitting the tire condition
signal and the unique tire identification indicator, and a controller for controlling the
transmitter so that the transmission of the tire condition signal and the unique tire identification indicator occurs when the first tire rotation signal indicates the tire has reached one of the at least two predetermined rotational positions during tire rotation. The apparatus further includes a second tire
rotation sensor (22) mounted external of the tire for sensing tire rotation and for providing a second tire rotation signal indicative of incremental angular position of the tire relative to a reference. A vehicle-based
receiver (44) receives the transmitted tire condition signal, the unique tire identification indicator, and the second tire rotation signal and correlates reception of the tire condition signal with the second tire rotation signal so as to associate the unique tire identification indicator with a particular tire location on the vehicle.