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.