TPMS and keyless entry can be difficult to understand because these systems rely on transmitting, receiving and decoding radio waves. You can see wires connecting modules and components, but seeing radio signals takes a little faith in science.
Radio waves are a type of electromagnetic radiation that have artificially organized patterns of waves so it transmits information. Still confused? Think of a TPMS sensor; it transmits a very low power signal that goes in all directions. The wave is absorbed and reflected off the vehicle and environment. The antenna on the vehicle, that could be on the windshield, in the wheel well or other locations, receives part of the wave.
TPMS sensor signals are low power and low frequency with the majority of sensors transmitting at 315MHz or 413MHz. Keyless entry fobs also operate at this frequency.
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