Hey there, I’m Robby – your trusted mechanic with over 20 years of experience repairing all types of vehicles. If there’s one pesky light that gives drivers headaches, it’s the low tire pressure warning. Maybe you’ve puzzled over it yourself. Why does it turn on sometimes but not others? Is it safe to drive with it on? And how do you make it shut off for good?
Well, buckle up because I’m going to shed some light on this common yet confusing dashboard symbol.
In this article, I’ll walk you through exactly what low tire pressure light flashing means, when you should be concerned, and how to properly maintain inflation to keep all four tires in their happy place. You’ll learn simple maintenance tips to prevent the light from ever turning on in the first place.
And if it does pop up – which happens to all of us – I’ll show you how to accurately diagnose the issue and reset the light once and for all. Even if cold weather is playing tricks on your tire pressure, my guide will have you rolling with confidence all year long.
So let’s get rolling! By the end, you’ll be a tire pressure pro.
What Does the Low Tire Pressure Light Mean?
The low tire pressure light, also known as the TPMS (tire pressure monitoring system) warning light, illuminates when one or more of your tires falls below the manufacturer’s recommended inflation pressure.
It’s represented by a horseshoe-shaped symbol with an exclamation point in the center. When illuminated, it signals that tire inflation should be verified using an accurate pressure gauge.
While underinflated tires are the most common cause, there are a few other reasons the light may turn on:
- Overinflated tires can also trigger the light in some vehicles. The sensors detect when pressure is outside the ideal range in either direction.
- A faulty TPMS sensor may send an incorrect reading. Individual sensors can malfunction over time.
- Switching to the spare tire may activate the light if the spare lacks a TPMS sensor.
- Extreme temperature fluctuations can impact air pressure and switch the light on temporarily.
Regardless of the cause, don’t ignore this important warning symbol when it appears. Doing so can lead to a dangerous situation.
Dangers of Underinflated Tires
Driving on underinflated tires poses risks including:
- Reduced braking ability and handling from lack of traction
- Increased chance of blowouts and sudden flats
- Accelerated uneven tire wear, especially on the shoulders and edges
- Reduced fuel economy from increased rolling resistance
Severe underinflation stresses the sidewalls, generating excessive heat that can lead to catastrophic tire failure. Maintaining proper inflation is essential for safety and maximizing the life of your tires.
When the Light First Illuminates
If the low tire pressure light comes on while driving, don’t panic. Remain focused on operating your vehicle safely. When possible, pull over and perform the following steps:
- Visually inspect all tires for obvious signs of damage or punctures.
- Use an accurate pressure gauge to check the inflation of all tires, including the spare.
- Compare the measured pressures to the vehicle manufacturer’s recommended specification, usually found on a sticker inside the driver’s door jamb. Do not rely solely on the pressures listed on the tire sidewalls.
- If any tires are underinflated according to the specs, add air until they reach the proper inflation. If a tire is damaged or completely flat, install your spare.
- Clear the TPMS warning light by driving for 5-10 minutes once tires are properly inflated. The light should reset itself and turn off.
Consistently Low Pressure
If the light frequently illuminates even after you’ve inflated your tires, suspect a leak. Tiny perforations in the tread or punctures from nails allow air to gradually seep out over time.
To find a leak, submerge each tire in a tub of water and look for bubbles. Mark the leak location with chalk. Most minor punctures can be permanently repaired by a tire shop in less than an hour.
If a leak can’t be found, the issue may be a stuck or damaged TPMS valve stem. These sensors screw onto the valve stem inside each wheel. Replace any damaged sensor immediately.
Temperature and Altitude Effects
As outside air temperatures drop in the evening and winter months, your tire pressures will also decrease. This is because the air density inside the tires changes with ambient temperature.
Colder air takes up less volume. A general rule of thumb is that for every 10°F temperature decrease, inflation pressure drops about 1 psi.
For example, if your tires are inflated to 32 psi on a warm 80°F summer day, they might read around 27 psi early the next morning when temperatures have dipped into the 30s. This 7 psi drop from summer to winter is enough to trigger the TPMS light.
A similar effect occurs when driving to higher elevations. Lower atmospheric pressure at altitude causes the relative pressure inside the tires to drop. Add 2 psi to the recommended pressures for every increase of 5000 feet above sea level.
Adjusting to Seasonal Changes
Since tire pressures fluctuate seasonally, don’t be surprised if your TPMS light illuminates during the first cold days of autumn and remains on for awhile throughout winter.
Try increasing inflation by 3-4 psi to offset the colder conditions. Turning on your heater while driving will warm the tires and help increase inflation as well. Consider keeping a portable air compressor in your vehicle during winter to adjust as needed.
Come spring, the TPMS light may activate again as rising ambient temps cause the tire pressures to increase back above the optimal range. Bleed off excess air as necessary to return to the recommended pressures.
Once you’ve properly inflated your tires, the TPMS warning light should turn off within a few minutes of driving. But if the light remains on after adding air, a manual reset may be required to clear the fault code that triggered the initial warning:
- Refer to your owner’s manual for make/model-specific reset procedures. Some vehicles automatically calibrate and reset after inflating and driving.
- Many TPMS resets require pushing a sequence of buttons on the dash while in “on” mode. Do not start the engine.
- If your spare tire was installed, reset procedures may need to be performed after reinstalling the repaired original wheel.
When in doubt about the proper reset process for your vehicle, consult a qualified tire shop or dealership service department.
Maintenance Tips to Prevent Low Tire Pressure
While the TPMS system provides a helpful alert, don’t rely on it alone. Performing routine maintenance and pressure checks can help prevent the light from illuminating in the first place:
- Check pressures at least once per month using an accurate dial or digital gauge. Do this when tires are “cold” before driving.
- Scan tires for embedded nails, cuts, and other damage during rotations.
- Have worn, aging tires inspected and replaced as recommended.
- Maintain proper wheel alignment to prevent uneven wear patterns.
- Load your vehicle and adjust tire pressures accordingly when carrying heavier loads.
By understanding common causes for your TPMS light to turn on, and responding appropriately when it does, you can ensure your tires remain properly inflated for safe driving. Performing preventive maintenance checks and resets will keep you rolling confidently down the road.
As your certified mechanic, I’m always available to answer any other questions about warning lights, tire safety, and proper maintenance at your convenience. Reach out anytime!
When to Ask a Mechanic
Maintaining your vehicle can be tricky business, especially diagnosing issues based on obscure dashboard warning lights. For expert troubleshooting advice from ASE-certified professionals, I recommend consulting a mobile auto mechanic in your area, or with our online mechanics. Whether it’s deciphering your TPMS warning, tracking down the source of an engine code, or inspecting new brake noises, the online mechanics at Mechanic Answer can provide knowledgeable guidance to keep your car running smoothly. Connect with them anytime for fast, affordable solutions from the comfort of your driveway!
In summary, while confusing at first, the low tire pressure light is easy to interpret and address once you understand the basics. Monitoring and maintaining proper inflation will keep you rolling safely for years to come. With proactive checks and resets, you can stay ahead of pressure drops and minimize unwelcome warnings. Your tires are one of the most important safety components, so when that light illuminates – take action!
Low Tire Pressure Light Flashing Frequently Asked Questions
Can I drive with a blinking tire pressure light?
It's not recommended to drive long distances with a blinking tire pressure light. This indicates one of your tires is significantly underinflated. Driving on a very underinflated tire can cause excessive wear, poor handling, and blowouts. It's best to pull over as soon as safely possible, check tire pressures with a gauge, and inflate any underinflated tires to the recommended PSI found in your owner's manual or door jamb sticker. You can drive a short distance to a service station to fill your tires.
Why is my tire pressure light blinking but my tires are fine?
A blinking tire pressure light can activate even if your tire pressures look fine visually. Small pressure losses of just a few PSI can turn the light on. The tire pressure monitoring system (TPMS) is very sensitive and designed to alert you to pressure losses well before a tire becomes visibly underinflated. Always rely on an accurate tire gauge to check pressures rather than just looking at your tires. The light will stop blinking once all tires are inflated to the proper PSI.
What is the difference between blinking and solid low tire pressure lights?
A blinking tire pressure light indicates a significant pressure loss, usually 25% or more below the recommended PSI. A solid light indicates a smaller pressure loss, typically between 10-25% lower than recommended. Both blinking and solid lights mean you should check pressures and fill tires ASAP. The blinking light is more urgent.
How do you fix a blinking tire pressure light?
The only way to fix a blinking tire light is to properly inflate your tires. Here's how:
Use an accurate tire pressure gauge to check the PSI in each tire.
Compare the measurements to the vehicle manufacturer's recommended tire pressure found on a sticker inside the driver door or in your owner's manual.
Fill any underinflated tires to the recommended cold PSI.
Drive for a few minutes to allow the TPMS to reset.
The blinking light should go off if pressures are within the proper range.
How long should I drive with my tire pressure light on?
You should not drive for long with the tire pressure light solid or blinking. It's unsafe and can damage tires. As soon as you see the light on, pull over when safe and check all tire pressures with a gauge. Ideally, inflate any underinflated tires immediately to turn the light off. If not possible, drive slowly and only far enough to reach a service station to fill your tires to the automaker's recommended PSI. Driving at highway speeds or for over 10 miles on an underinflated tire risks damage and blowouts.