Your tire pressure light means at least one tire is underinflated or overinflated
The tire pressure warning light — usually a picture of a tire with an exclamation mark inside it — turns on when your vehicle's tire pressure monitoring system (TPMS) detects that one or more tires are not at the correct pressure. This is not a breakdown warning. It means your tires need attention before you drive much further, but you can usually drive safely to a gas station or tire shop to check and adjust them.
The light can mean different things depending on how it looks. A steady light that stays on means at least one tire is significantly underinflated or overinflated right now. A light that blinks for a few seconds when you start the car and then goes off usually means the TPMS sensor itself has a problem — the system cannot read the pressure, not that the pressure is wrong.
Key Takeaways
- A steady tire pressure light means one or more tires are outside the correct pressure range and need to be checked and adjusted as soon as practical.
- The correct pressure for your tires is printed on a sticker inside the driver's door jamb, not on the tire itself — the number on the tire is the maximum pressure it can hold.
- Cold weather, a slow leak, or a faulty sensor can all trigger the light, and you will need to check your tires to know which one.
- If the light blinks when you start the car and then stops, the problem is the sensor, not the tire pressure — you can still drive, but the system will not alert you to future pressure problems.
Where to find the correct tire pressure for your vehicle
Your vehicle's correct tire pressure is printed on a white or silver sticker on the inside of the driver's door jamb — the edge of the door frame you see when you open the door. The sticker lists the pressure in pounds per square inch (psi) for the front and rear tires, and sometimes different pressures for different load conditions. This is the pressure you should maintain, not the number printed on the tire itself.
The number on the tire sidewall is the maximum pressure that tire can safely hold, not the target pressure for your vehicle. Using that number instead of the door jamb number will overinflate your tires and trigger the warning light. Write down the correct pressure from your door jamb sticker before you go to a gas station so you have it with you.
How to check and adjust your tire pressure
You will need a tire pressure gauge, which you can buy at any auto parts store or gas station for a few dollars, or borrow from a friend. Most gas stations have free air pumps near the fuel pumps. Some are manual (you control the air flow), and some are automatic (they stop when the tire reaches the set pressure). Read the instructions on the pump before you use it.
Remove the valve cap from one tire — it is a small plastic or metal cap on the tire stem. Press the gauge onto the valve stem firmly until you hear a small hiss of air. The gauge will show the current pressure. If it is lower than the door jamb number, use the air pump to add air. If it is higher, press the small button on the valve stem to release air. Check all four tires, including the spare if your vehicle has a TPMS sensor in it. Once all tires match the door jamb pressure, replace the valve caps and drive normally. The light should turn off within a few minutes of driving.
Why the light came on: cold weather and slow leaks
Tire pressure drops in cold weather because air contracts when it cools. For every 10 degrees Fahrenheit the temperature drops, tire pressure falls by about 1 psi. If you park outside overnight in winter or drive in a cold snap, your tires may drop below the correct pressure even if they were fine the day before. This is normal and not a sign of a leak — check and adjust the pressure, and the light will go off.
A slow leak means air is escaping from the tire gradually, usually through a small hole or a faulty valve stem. If you check the pressure and find one tire is consistently lower than the others, or if the light comes back on within a few days of adjusting, you likely have a slow leak. A tire shop can locate the leak and patch it, or replace the tire if the damage is too large to repair. Do not ignore a slow leak — driving on an underinflated tire damages the tire and wastes fuel.
When the light blinks instead of staying steady
If the tire pressure light blinks for a few seconds when you start the car and then turns off, the problem is not your tire pressure — it is the TPMS sensor. The sensor is a small device inside each tire that measures pressure and sends the reading to your vehicle's computer. When a sensor fails, the light blinks to tell you the system cannot read the pressure anymore.
You can still drive with a faulty sensor, but your vehicle will not alert you if a tire becomes underinflated in the future. You should have the sensor replaced at a tire shop or dealership. Replacement usually costs between $50 and $150 per sensor, depending on your vehicle. Until you replace it, check your tire pressure manually once a month to make sure none of your tires are losing air.
What to do right now if the light is on
First, check whether the light is steady or blinking. If it is blinking, the sensor is faulty and you can drive normally — just plan to have it checked soon. If it is steady, drive to a gas station or tire shop within the next few hours and check your tire pressure against the door jamb sticker. Adjust any tires that are out of range. If all four tires are at the correct pressure but the light is still on, the TPMS sensor in one tire may be faulty, and you should have it checked at a tire shop.
Do not ignore the light for days or weeks. Driving on significantly underinflated tires damages the tire, reduces fuel economy, and makes your vehicle harder to control in an emergency. Checking the pressure takes ten minutes and costs nothing.
Frequently Asked Questions
Can I drive on the highway with the tire pressure light on?
Yes, if the light is steady and you have checked that at least one tire is only slightly low. If a tire is very low (more than 5 psi below the correct pressure), drive slowly to the nearest gas station or tire shop instead of the highway. If the light is blinking, the sensor is faulty but your tires are likely fine — you can drive normally.
Why does the light come on only in winter?
Cold air contracts, so tire pressure drops when the temperature falls. If your tires are already close to the minimum pressure in warm weather, they will drop below it when it gets cold. Check and adjust your pressure in fall before the temperature drops, and again in spring when it warms up.
What if I adjust the pressure and the light stays on?
Drive for a few minutes — the light usually turns off within five to ten minutes of driving once the pressure is correct. If it stays on after that, one of your TPMS sensors may be faulty. Have a tire shop read the vehicle's computer to see which sensor is not reporting.
Is it safe to drive with the tire pressure light on?
It depends on how low the pressure is. A tire that is 3 to 5 psi low is safe to drive on for a short distance. A tire that is 10 or more psi low can overheat and fail. Check your pressure when ready — if any tire is more than 10 psi below the door jamb number, drive slowly to the nearest tire shop and do not use the highway.