What does it mean if the Tire Pressure Monitoring System light comes on in the dash?
If the Tire Pressure Monitoring System light (TPMS) light comes on in the dash of your car, it indicates there’s a problem with the system itself, not that there’s a tire low on air. The TPMS light means that the system isn’t able to communicate with a sensor. There are a couple of reasons for this to happen:
The spare tire is installed on the car (the spare doesn’t have a sensor, so the TPMS light will come on normally).
One of the sensors has failed to communicate with the system.
If the light is on but you’re not driving with your spare tire on the car, have it inspected as soon as possible.