Tire Pressure Sensor Service Video

A tire pressure sensor is a small battery-powered transmitter mounted inside each wheel. It reports the tire's pressure to a receiver in the vehicle. The receiver turns on the dash warning when a tire drops about 25 percent below the pressure on the door placard.

This video shows where the sensor sits inside the wheel and what a corroded valve stem looks like next to a healthy one. It also walks through the relearn step that pairs a new sensor with the vehicle after it is installed.

Each sensor is a sealed unit with a pressure gauge, a radio transmitter, and a lithium battery, usually mounted to the valve stem. The battery cannot be replaced, so when it runs down after several years, the whole sensor is replaced. Sensor service is part of our suspension, steering, and wheel service, which covers everything from the wheels to the steering rack.

Replacing a sensor means dismounting the tire, fitting a new sensor or a service kit with a fresh grommet, nut, and valve core, then remounting and balancing. Some vehicles relearn the new sensor after a short drive, while others need a scan tool to write its ID to the vehicle.

A warning light that stays on after all four tires are set to the correct pressure is the clearest sign of a sensor fault. A dead battery or failed transmitter is the usual cause, not a low tire.

At Spectra Auto Services, our technicians scan the system first to find which wheel is reporting the fault. They check whether the problem is the sensor, the valve stem hardware, or the receiver. You get DVI photos and the fault details before any parts are replaced.

A tire that ran low for weeks before the sensor was fixed may already be wearing unevenly. Our wheel alignment service includes a tire and TPMS check, so pressure readings are accurate before the angles are set.

Winter road salt in Frederick County can corrode aluminum valve stems where they contact brass valve cores. Over time, this corrosion can weaken the stems and cause them to break during a routine tire change. Drivers from Mount Airy and Middletown often learn their sensors are due this way.

If your tire pressure light will not go off, call Spectra Auto Services at (301) 695-5990, or visit your mechanic in Frederick to have the sensors tested.