A Tire Pressure Monitoring System uses electronic sensors inside the wheel assembly or relies on wheel speed sensors to track tire inflation. Direct TPMS uses battery-powered valve-stem sensors that transmit exact pressures via radio frequency to the ECU, while indirect TPMS calculates pressure drops by detecting changes in wheel rotational speed.
Heard on the job
The customer hit a massive pothole and snapped the TPMS sensor right off the valve stem.
Insider tip
When replacing tires on direct TPMS wheels, always rebuild the valve stem with a new seal kit to prevent slow leaks.
Also heard as
- Tire Pressure Monitoring System