How does the tpms on your 2008 explorer sport trac technically work?

Answer 1

Each wheel has a tire pressure sensor on it, which detects the pressure of the tire, and has a radiotransmitter that reports that pressure to the TPMS computer. The computer compares to the pressure reported by the sensor to the expected pressure programmed by Ford at the factory (as far as I know, this cannot be changed even at the dealer). If there is a certain discrepancy between expected and reported (I believe that it may be 4PSI under expected), it throws the dash light and the 'TIRE PRESSURE LOW' or similar message on your Message Center. Below a certain pressure, that low pressure warning on the M/C changes to "WARNING - TIRE VERY LOW" or similar. If a problem is detected with the TPMS system (computer trouble, sensor malfunction, missing sensor signal, etc), the computer again fires off the dash light, and you get a 'TPMS FAULT' or similar message on the M/C.