TPMS Light On: What the Tire Pressure Warning Means

The TPMS (Tire Pressure Monitoring System) warning light on your dashboard means at least one tire is significantly under-inflated. In Houston, where road debris and potholes are common, understanding this system helps you respond correctly.

What triggers the TPMS light

Direct TPMS uses pressure sensors inside each tire that transmit wireless readings to the car's computer. The light illuminates when any tire drops 25 percent or more below the recommended pressure. Indirect TPMS uses wheel speed sensors to detect when one tire rotates faster than the others (indicating lower pressure and a smaller rolling circumference).

Common reasons the TPMS light comes on

Temperature change: tire pressure drops about 1 PSI for every 10-degree temperature drop. A Houston cold front can trigger the light overnight. Slow leak: a nail or screw in the tread, a damaged valve stem, or a corroded wheel rim can cause a gradual leak. Flat tire: obvious, but some run-flat tires can lose significant pressure without feeling different to the driver. Failed TPMS sensor: the battery inside the sensor (non-replaceable) typically lasts 5 to 10 years. When it dies, the sensor stops transmitting and the light illuminates.

What to do when the TPMS light comes on

Check all four tires visually for obvious flats. Use a tire gauge to check each tire's pressure against the placard on the driver's door jamb. Inflate any low tires to the recommended pressure. If the light stays on after inflating, you may have a slow leak or a failed sensor.

Mobile TPMS service

FlexFix checks tire pressure, identifies slow leaks, and diagnoses TPMS sensor issues at your location in Katy, Sugar Land, Cypress, and greater Houston. If a sensor has failed, we can replace it on-site for most vehicles.