Why is my tire pressure light on?
A steady tire pressure (TPMS) light means at least one tire is at least 25% below its recommended pressure, often because cold mornings lower the pressure. Check all four tires with a gauge and fill them to the pressure on the sticker inside the driver's door. If the light flashes for about a minute at startup and then stays on, a sensor or the system itself has a fault.
What the light is telling you
Since 2008, cars sold in the US have a tire pressure monitoring system (TPMS). It warns you when a tire is significantly underinflated, which affects braking, handling, fuel economy and tire life.
There are two common patterns:
| What you see | Meaning |
|---|---|
| Light stays on steady | One or more tires are low |
| Light flashes about a minute, then stays on | A TPMS fault, often a dead sensor battery |
What to do
- Check all four tires, plus the spare if it has a sensor, with a gauge when the tires are cold.
- Fill to the door-jamb pressure. Many gas stations have air; some cars have a tire fill alert that honks when you reach the target.
- Drive a few miles. The light usually goes off once the system rereads the tires.
- Check again in a day or two. If one tire is low again, it has a slow leak, often a nail, a leaking valve stem or a corroded wheel bead.
When to have it looked at
- One tire keeps losing air
- The light flashes, then stays on
- A tire has a visible nail, bulge or cut
- The light came on suddenly at highway speed and a tire looks noticeably low
A nail in the tread can usually be repaired properly from the inside. Tire repair.
From drivers who came to us
He checked my car tire pressure after a warning light went off on the highway. He patiently answered a bunch of our questions and ensured we'd be safe to get back on the highway for our family trip.
My car had a screw in the tire, they fixed it within 30 mins!
I brought in my Lexus as there was an issue with one of my tires. They were able to locate the tear in the tire and patch it quickly.
Excerpts from verified customer reviews on Yelp.
More questions
Why does the light come on when it's cold?
Tire pressure drops about 1 PSI for every 10°F drop in temperature. A tire that was borderline on a warm afternoon can trigger the light on a cold morning.
What pressure should my tires be?
Use the pressure on the placard on the driver's door jamb or in the owner's manual, measured cold. The number on the tire sidewall is the maximum, not the recommendation.
Is it safe to drive with the tire pressure light on?
For a short distance to air up, yes, as long as no tire is visibly flat. Driving on a badly underinflated tire overheats it and can cause a blowout.
Why is the light on when all my tires look fine?
Tires can lose a lot of pressure before they look low. Check with a gauge. If the pressures are correct and the light stays on, a sensor may have failed; their batteries typically last 5 to 10 years.