A solid tire pressure (TPMS) light means at least one tire is significantly below its recommended pressure. Check all four with a gauge and inflate them to the number on the driver's door jamb. A light that flashes for about a minute and then stays on means a TPMS system fault, often a sensor with a dead battery.
Solid vs. flashing
| Light | Meaning | What to do |
|---|---|---|
| Solid | One or more tires are low, typically about 25% below spec | Check and inflate all tires |
| Flashes ~60–90 seconds, then stays solid | TPMS malfunction: dead sensor, missing sensor or a system fault | Have the system diagnosed |
| Comes on in cold mornings, off by afternoon | Pressure is borderline low | Top up to spec |
Why the light comes on when it gets cold
Tire pressure drops roughly 1 psi for every 10°F drop in temperature. The first chilly morning in the fall can drop a borderline tire below the warning threshold. Then it warms up and the light goes off. Top them up.
Where to find the right pressure
Use the placard on the driver's door jamb, not the number on the tire sidewall. The sidewall shows the maximum pressure the tire can handle, not what your vehicle needs. Check pressures cold, before driving or after the car has sat a few hours.
When a sensor fails
Most TPMS systems use a sensor inside each wheel with a built-in battery. Those batteries often last somewhere around 5–10 years, and when they die, the sensor needs to be replaced. You'll see the flashing-then-solid pattern.
Other causes:
- A damaged sensor from a tire change or pothole
- Winter or spare wheels without sensors
- A system that needs relearning after a tire rotation or a new sensor
Don't ignore a low tire
A low tire wears unevenly, runs hotter, increases stopping distance and hurts fuel economy. Under-inflation is a major cause of blowouts, especially at highway speeds in summer heat. If one tire keeps losing pressure, look for a nail, a leaking valve stem or a bead leak.
Frequently asked questions
How do I reset my tire pressure light?
On most vehicles, inflating the tires to the correct pressure and driving a few miles turns it off. Some have a reset button or menu procedure. After sensor replacement, a relearn is often required.
Is it safe to drive with the TPMS light on?
Check your tires as soon as possible. If a tire is visibly low or losing air quickly, don't drive on it.
Why is my TPMS light on when my tires look fine?
Tires can be 25% low and still look normal. Use a gauge. If they're all at spec and the light is flashing first, it's a sensor or system issue.
Can you replace TPMS sensors on-site?
Sensors are mounted inside the wheel, so replacement involves dismounting the tire. We'll diagnose the system and tell you exactly what's needed.
Want a mechanic to confirm it?
We come to you in Lexington, Irmo, Chapin, Cayce, West Columbia and Columbia, and we test before we replace anything.
