Ever looked at your dashboard and thought, “Why is my TPMS light on?”
That little horseshoe-shaped symbol is your tire pressure monitoring system warning you that something’s off with your tires. It could be low pressure, a slow leak, or a faulty TPMS sensor.
But here’s what most drivers miss:
How your TPMS light behaves — solid, flashing, or flickering — can hint at exactly what’s wrong.
Keep reading as we’ll help you understand what a lit TPMS light means, its causes, and the steps a mechanic may take to reset it.
This Article Contains:
- Why Is Your TPMS Light On & What Do Different Light Patterns Mean?
- How Urgent Is the TPMS Light?
- How to Reset the TPMS Light
- 3 FAQs about the TPMS Alert
Why Is Your TPMS Light On & What Do Different Light Patterns Mean?
Here’s a breakdown of TPMS light behaviors and the usual culprits behind them:
1. TPMS Light Comes On While Driving and Stays On
Tires naturally lose air over time, and pressure can drop suddenly if you hit a curb, pothole, or debris. Even a slight drop below the recommended pounds per square inch (PSI) is enough to set off the warning and cause it to stay on.
What to Do:
To diagnose the issue, get a mechanic to first visually inspect the tires. If there’s no visible damage, they’ll use a tire pressure gauge to check each tire and compare the readings with the vehicle’s recommended pressure range, typically between 28 and 36 PSI.
2. TPMS Light Goes On and Off
If your low tire pressure light comes on in the morning but disappears after a few minutes of driving, sudden air temperature changes are likely the culprit.
Tire pressure can drop about 1 to 2 PSI for every 10°F decrease in air temperature. As a result, the light often appears on cold mornings and goes away as the tires warm up and pressure stabilizes.
However, even if the light turns off, it’s still a good idea to have your tire pressure checked.
What to Do:
Your mechanic will use a tire gauge to check the tire’s pressure and inflate any underfilled ones using professional tools. Once corrected, the light should turn off after a short drive.
3. TPMS Light Comes Back After Reset
Sometimes, you inflate your tires and reset the system, only for the light to return a day or two later. This often indicates a slow leak. This can be caused by a nail, sharp debris, or even a loose valve stem letting out small amounts of air.
What to Do:
Since these leaks aren’t always visible, it’s best to have a professional inspect your tires and patch or replace them as needed.
4. TPMS Light Stays On After Tire Rotation or Replacement
After getting new tires or rotating your existing ones, the TPMS system may need a reset.
Why?
If the tire pressure sensor isn’t recalibrated properly, the system might not recognize the proper pressure, even if everything is fine.
What to Do:
In this case, a technician can reset or reprogram the system to ensure it works correctly with the new tire setup.
5. TPMS Light Flashes, Then Stays On
If the TPMS light flashes for a minute or so after startup and then turns solid, it usually means there’s a problem with the TPMS system itself, not just your tire pressure.
It can happen if the TPMS sensor is damaged or its internal battery is dead, preventing the system from reading your tire pressure accurately and triggering the warning light.
What to Do:
To address the issue, your mechanic will diagnose the problem and replace the faulty tire pressure sensor to restore proper function.
NOTE: If your TPMS warning light (or low tire pressure light) comes on while driving, don’t panic. Keep both hands on the wheel, slow down gently, and pull over when it’s safe. If you’re unsure about your tires, call a tow truck and have your car taken to the nearest gas station or service center, where a mechanic can inspect them.
Curious if it’s important to get it checked soon?
Let’s break it down.
How Urgent Is the TPMS Light?
A tire pressure monitoring system light is a warning you shouldn’t ignore.
If the light flashes for a minute and stays on, it’s more urgent, usually indicating a faulty sensor or system malfunction. This means your TPMS may not detect future pressure drops, increasing the risk of tire failure.
On the other hand, if it’s solid, it typically means one or more tires are underinflated. While not an emergency, driving with low pressure can reduce your vehicle’s fuel efficiency and cause poor handling or uneven tire wear.
Bottom line: Have an auto repair expert inspect and reset a lit TPMS light ASAP.
How to Reset the TPMS Light
In many cars, the TPMS light will turn off automatically once all tires are inflated to the proper pressure. However, in some vehicles, you need to reset it manually.
If you skip this step or reset the light without fixing the issue, the system may give false alerts or miss real problems. That’s why it’s best to schedule service with an auto repair professional.
Here’s what they’ll do:
- Check and adjust the pressure: They’ll use a tire pressure gauge to check that all your tires (even the spare) are inflated to the recommended pressure. This information is usually listed on the driver’s side door placard or in your owner’s manual.
- Use the TPMS reset button: Some cars may have a TPMS reset button near the dashboard or under the steering wheel. If your vehicle has one, the mechanic will turn on the ignition, then press and hold the button until the light blinks.
- Drive to auto-reset: In some vehicles, once the tires are inflated to the correct pressure, the system may reset automatically after driving at a steady speed for 10 to 20 minutes.
Have more questions?
Check out these FAQs.
3 FAQs about the TPMS Alert
Here are the answers to common questions you may have about the TPMS warning light:
1. Do You Need to Manually Check Tire Pressure Despite Having a TPMS?
Yes.
While TPMS helps detect low tire pressure, it isn’t always foolproof. Sensors can wear out over time, and temperature changes can affect pressure without immediately triggering a warning.
That’s why it’s best to consult your owner’s manual and check the tire pressure manually using a tire gauge every few months. This helps improve tire life and ensure overall vehicle safety.
2. What’s the Difference Between a Tire Pressure Light and the TPMS?
The tire pressure light (or the tire light) is a dashboard warning symbol that turns on when the TPMS detects low pressure or a related issue. Meanwhile, the TPMS is the system that monitors the air pressure in your tires.
There are two types of TPMS:
- Direct TPMS: Uses sensors inside each tire to provide accurate air pressure readings and helps maintain the correct pressure level.
- Indirect TPMS: Relies on wheel speed sensors and the Anti-lock Braking System (ABS) to estimate tire pressure by monitoring how fast each wheel spins.
3. Can You Drive with the TPMS Light On?
You can, but it’s not recommended.
Ignoring the tire light for prolonged periods can lead to:
- Poor handling
- Longer braking distances
- Uneven tire wear and blowouts
- Lower fuel efficiency
In more serious cases, especially if the system malfunctions, your car may not alert you if a tire drops below the recommended pressure, putting vehicle safety at risk.
TPMS Trouble? Let AutoNation Mobile Service Fix It Fast
If your TPMS warning light stays on or keeps flashing, don’t ignore it — every mile you drive with a tire issue increases the risk of a blowout.
Not sure what’s triggering the alert?
AutoNation Mobile Service has your back.
Our expert mobile mechanics come to you to inspect your tires, inflate them to the recommended level, and replace a faulty sensor on-site. We also provide upfront pricing and a 12-month, 12,000-mile repair warranty for added transparency.
Book a service today and keep the pressure where it belongs: in your tires, not your mind.