A tire condition sensing apparatus includes a tire-based sensor for sensing two relative rotational positions of its associated tire relative to the earth's horizon as the tire rotates and provides first and second signals indicative thereof. A transmitter for transmits tire condition information and a signal processing time delay value in response to the first and second signals. A vehicle-based sensor monitors tire rotation relative to the vehicle's chassis and provides a signal indicative thereof. A controller for monitors the transmitted tire condition information signal, the signal processing time delay value, and the signal from the vehicle-based sensor and associates tire location in response thereto.