A tire sensor that communicates to a remote interrogator in one of two
modes depending on the nature of the interrogation. The interrogator may
be distributed throughout a vehicle if needed for design options.
Further, the interrogator only interrogates the transponder when the
interrogator has reason to believe that the transponder is in range of
the interrogator. The interrogator and transponder may be configured to
operate in different modes for communication during operation of the tire
on a vehicle and during non-operation. The transponder may communicate
tire condition information to the interrogator concerning environmental
or other information sensed about the tire.