# That Tire-Pressure Light: TPMS, Explained

> What the TPMS tire-pressure light means, why it comes on in cold weather, and when it signals a leak or a failing sensor.

*Tab Motors Auto Repair | Exxon, 4035 Old Dominion Dr, Arlington, VA 22207 · (703) 243-3080*

The little horseshoe-shaped light with an exclamation point is your Tire Pressure Monitoring System (TPMS), and it confuses a lot of drivers. Here's what it's actually telling you.

## Why it loves cold mornings

Air contracts as it cools, so a cold snap can drop your tire pressure enough to trip the light, even with no leak. Tire pressure falls roughly 1 PSI for every 10°F drop, which is why the light so often appears on the first cold morning of the season. Topping the tires back up to the correct pressure usually clears it.

## When it means a real problem

If the light keeps coming back after you've properly inflated the tires, you likely have a **slow leak**, a nail, a bad valve stem, or a wheel that isn't sealing. And if the light *flashes* for a bit before staying on, that often points to a **failing TPMS sensor** (the sensors have small batteries that eventually die, usually after several years).

## Why correct pressure matters

- Underinflated tires wear out faster and unevenly

- They hurt fuel economy

- They can overheat at highway speed, a blowout risk

- Correct pressure gives you the best grip and braking

## Don't just ignore it

Taping over the light isn't a fix. At TAB Motors we [diagnose the TPMS](../services/tire-wheel-service.html), find any leak, set your pressures to spec, and service sensors when needed, so the light goes off and stays off. Call (703) 243-3080.

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Call (703) 243-3080 or visit TAB Motors | Exxon at 4035 Old Dominion Dr, Arlington, VA 22207.