If your tire pressure light keeps coming on, you are not alone. We see this all the time at Nelson Auto Repair, especially when the weather changes in Naperville and around the Chicagoland area. One cold morning can make the light pop on, then it turns off later in the day, then comes back again. It gets annoying fast.
The good news is this light does not always mean you have a flat tire. But it does mean your car is trying to tell you something. Sometimes it is low air pressure. Sometimes it is a slow leak. Sometimes the TPMS sensor itself is the problem.
What Is the Tire Pressure Light and What Is TPMS?
The tire pressure light is part of your TPMS, which means Tire Pressure Monitoring System. This system watches the air pressure in your tires. If one tire gets too low, the light comes on.
Most cars have one of these warning symbols:
- A yellow tire shape with an exclamation point
- A message that says “Low Tire Pressure”
- A TPMS warning light that blinks, then stays on
If the light is solid, you usually have a pressure problem. If it blinks first and then stays on, that often means a sensor or system fault. Thats a big clue.
Low Tire Pressure Is the Most Common Reason the Light Keeps Coming On
This is the number one cause. Tires lose a little air over time. That is normal. A tire can lose around 1 to 2 PSI per month, and cold weather can make it drop even more.
In Illinois, this happens alot in fall and winter. When temps dip overnight, your tire pressure drops. Then in the afternoon it warms up and the pressure goes up a little. That is why the light may come and go.
A simple pressure check with a gauge can solve a lot of this. Check all four tires, not just the one that “looks low.” Also check the spare if your vehicle monitors it.
Cold Weather and Tire Pressure Light Problems in Naperville
This is a huge local issue. Every year when we get those first cold snaps, we get a wave of TPMS lights. People think something broke, but many times it is just pressure dropping from the temp swing.
Rule of thumb:
- For about every 10 degree drop in temperature, tire pressure can drop around 1 PSI
So if your tires were a little low already, the first cold week can push them below the warning threshold. Then the light starts popping on every morning. Pretty common around here, honestly.
Slow Tire Leak Can Make the Tire Pressure Light Keep Returning
If you fill your tire and the light comes back in a day or two, you may have a slow leak. This is also very common.
Common slow leak causes:
- Nail or screw in the tread
- Leak around the valve stem
- Bead leak where tire meets rim
- Corrosion on the wheel (we see this a lot with salt exposure)
- Tiny puncture that is hard to spot
Road salt and potholes around this area can make leaks more likely. A wheel can get bent a little, or rust can build up on the rim, and then the tire will not seal right. It may not go flat fast, but it will keep setting off the light.
Tire Pressure Light Comes On but Tire Looks Fine
This happens all the time. A tire can be low and still look normal. Modern tires have stiffer sidewalls, so they can hide low pressure better than older tires.
That is why you should not trust your eyes only. Use a pressure gauge and compare to the sticker on the driver door jamb. Do not use the max PSI printed on the tire sidewall as your target. That number confuses a lot of people.
If one tire is even 5 to 8 PSI low, it can trigger the warning light and still look “okay” to the eye.
TPMS Sensor Problems Can Trigger the Tire Pressure Warning Light
Sometimes the tire pressure is fine, but the light keeps coming on because the TPMS sensor is failing. Each wheel usually has a small sensor inside the tire, attached to the valve stem or banded to the wheel. These sensors have small batteries inside them.
Those batteries do not last forever. Many TPMS sensors start failing after several years.
Signs of a TPMS sensor issue:
- TPMS light blinks, then stays on
- Tire pressures are all correct but light remains on
- Light comes on after tire work or battery replacement
- One sensor is not reading on a scan tool
This is not always urgent like a flat tire, but it should be fixed so your warning system works right when you need it.
Wrong Tire Pressure After a Tire Rotation or Tire Service
Sometimes the light comes on after a tire rotation, new tires, or flat repair. A few things can cause that:
- Tire pressures were not set correctly after service
- TPMS system was not reset (on vehicles that require a reset)
- Sensor got damaged during tire mounting
- New sensor was not programmed correctly
This is pretty easy to sort out with the right scan tool. At the shop, we can read each sensor, see live pressure data, and tell if the issue is pressure, a dead sensor, or a relearn problem. If you need help, a quick inspection at Nelson Auto Repair vehicle inspections can save a lot of guesswork.
Why You Should Not Ignore a Tire Pressure Light
It may seem like a small thing, but low tire pressure can cause bigger problems:
- Poor gas mileage
- Uneven tire wear
- Bad handling
- Longer stopping distance
- Higher risk of blowout
- Extra wear on suspension parts
A tire that is low runs hotter. Heat is what kills tires. So even if the car still drives, the tire can be getting damaged while you keep putting it off. We see this pretty often after long highway driving.
How to Fix a Tire Pressure Light That Keeps Coming On
Here is a simple step by step plan:
- Check all four tires with a gauge when tires are cold.
- Inflate to the PSI on the driver door sticker.
- Drive a few miles and see if the light goes off.
- If the light comes back, inspect for nails or damage.
- If no leak is obvious, have the TPMS sensors tested.
- If the light blinks first, ask for a TPMS scan and relearn check.
This is one of those things where a quick test can save money. A lot of people replace sensors first when they really just had a slow leak. Other times they keep adding air for months when the sensor battery is actually dead. Both happen alot.
Tire Pressure Light in Winter vs Summer
The seasons matter. In winter, the light is often from pressure drop. In summer, the light may point more toward:
- A leak that got worse
- Heat expansion causing pressure swings if tires were overfilled
- TPMS sensor battery failure showing up after temp changes
Pothole season can also mess with tires and rims. If your light started after hitting a pothole, get the tire and wheel checked right away. We have seen bent wheels from what looked like a “small” hit.
When to Call a Local Shop for TPMS and Tire Pressure Problems
You should get it checked if:
- The light keeps coming back after adding air
- You have to refill the same tire often
- The TPMS light blinks
- The car pulls to one side
- You see uneven tread wear
- You hit a pothole and the light started after that
A local shop can usually test this quickly and tell you if it is a tire leak, rim issue, or sensor problem. That is way better than guessing and hoping it goes away.
Why Nelson Auto Repair Sees This Problem So Often
At Nelson Auto Repair, we work on a lot of daily drivers in the Naperville area, and TPMS issues are one of the most common warning lights we see when the seasons change. Between cold mornings, potholes, road salt, and normal tire wear, there are a bunch of reasons this light pops on around here.
We can check tire pressure, inspect for leaks, test the TPMS sensors, and make sure the system is reading correctly. If your tire pressure light keeps coming on, bring it in before it turns into tire damage or a roadside problem.
