An apparatus (10) determines a tire condition and location on a vehicle (12) including a tire-based sensing unit (14) including, a first tire rotation sensor (66) for providing a first tire rotation signal (80) each time the tire passes one of at least two predetermined rotational positions and an unique tire identification indicator, a transmitter (86) and a controller for controlling the transmitter so that the transmission occurs when the first tire rotation signal indicates the tire has reached one of the at least two predetermined rotational positions. 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) correlates reception with a particular tire location on the vehicle.