Why Your Tire Pressure Light Keeps Coming On

That little horseshoe-shaped light on your dash is the tire-pressure warning, and when it won't go off it's easy to start tuning it out. Here's what's usually behind it.

A tire really is low

The most common reason, and the one worth ruling out first. Temperature swings alone can drop pressure enough to trip the light, especially overnight. Air all four tires to the pressure listed on the sticker inside your driver's door — not the number on the tire sidewall — and see if the light clears after a short drive.

A slow leak you can't see

If a tire keeps going low after you fill it, you've likely got a slow leak from a nail, a corroded valve, or a bead that isn't sealing. This is worth fixing sooner rather than later, because a slow leak has a way of becoming a flat at the worst moment.

A dead or confused sensor

The sensors inside your wheels run on small batteries that age out, usually somewhere between five and ten years. A dead sensor leaves the light on no matter how much air you add. And after new tires are installed, the system sometimes needs a relearn so it recognizes each sensor in the right spot — if your light came on right after a tire service, that's often the cause.

When to get it looked at

If the light stays on after you've aired the tires up correctly, flashes at startup, or came on right after new tires, have the TPMS checked. We handle sensor testing, replacement, and the relearn on-site — no shop visit needed.

A warning system you can't trust is worse than none, because you stop checking. Let's get it reading right.