Why Your TPMS Light Came On (and What to Do Next)

See that little horseshoe with an exclamation point glowing on the dash? That’s your Tire Pressure Monitoring System (TPMS) telling you one or more tires are unhappy.

Why It Happens

TPMS keeps tabs on tire pressure through sensors inside the wheels. If pressure drops below a set point, the light comes on. Sometimes it’s a legit leak, other times it’s just a cold morning shrinking the air. Ignore it, and you’re risking poor handling, bad fuel economy, or a blowout.

Most Common Causes

• Low tire pressure – slow leak, nail, or just neglected top-up.
• Sudden puncture – rapid drop sets the light instantly.
• Cold weather – pressure naturally drops with temperature.
• Faulty TPMS sensor – dead battery or damaged unit.
• Tire swap without reprogramming – system can’t see the new sensors.

What You Can Check

What a Mechanic Will Check

• Inspect and repair any punctures.
• Reset TPMS and relearn sensors if needed.
• Replace faulty or dead TPMS sensors.

Ballpark Repair Costs

• Tire top-up: Free–$20.
• Puncture repair: $25–$50.
• New TPMS sensor: $80–$150 each.
• Full set of sensors: $300–$500 installed and programmed.

When to Call It Quits

If the light’s on solid and you can see or feel a flat, don’t drive it. Flats shred fast, and you’ll be buying a tire instead of a $30 plug. Flashing TPMS light? That’s a system fault — safe to drive short-term, but get it fixed or you’ll never know when a real flat happens.