Why is my TPMS light still on after I set the tire pressures?
Short answer: The system may need time driving to update, a relearn procedure, or it may be reporting a failed sensor, a missing sensor ID or a spare tire sensor; a TPMS tool shows which.
Many systems clear the warning only after the vehicle drives for a short time and receives fresh readings from each sensor. Some vehicles need a reset or relearn after pressures are adjusted, especially indirect systems that learn from wheel speed data.
If the light flashes for a period at startup and then stays on, that usually indicates a system fault rather than low pressure, such as a dead sensor battery, a damaged sensor, or a sensor ID the module does not recognize after new wheels or tires. Some vehicles also monitor the spare.
A TPMS tool can trigger each sensor to confirm it transmits, read its ID, pressure and battery status, and compare it with what the module has stored. Set pressures to the placard on the door jamb rather than the maximum on the tire sidewall. Never drive on a tire that is losing air; use a jack and stands safely if a wheel must come off.
Tools used for this job
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.