Kate is a research enthusiast with a Bachelor of Science degree from Sonoma State University. Kate has a passion for the automotive field.
The low tire pressure light on your car (also known as the TPMS light) should turn off when you have filled your tires to the proper pressure in terms of PSI (pounds per square inch). Sometimes, however, it just doesn't work. The light doesn't always reset, and that can leave you with an annoying orange light or—with some newer vehicles—a constant message on your display that your tire pressure is low.
If you have ensured that the tire pressure is fine in each of your tires, including your spare (yes, they often have sensors too), and the warning light still refuses to turn off, here are a few methods you can use to try to reset it.
4 Ways to Turn off the Low Tire Pressure (TPMS) Light
1. Drive at 50 mph for 10 miles.
2. Use your vehicle's TPMS reset button.
3. Deflate and reinflate the tires.
4. Disconnect and reconnect the car's battery.
1. Drive at 50 MPH for 10 Miles
The easiest method is to drive about 10 miles at 50 mph. If you can, use the cruise control feature to keep the speed constant. Some vehicles reset their sensors at higher speeds than others. When you're done, park and shut off the car. The next time you start it, the light should go off.
2. Use Your Vehicle's TPMS Reset Button
Each tire has a sensor. Sometimes the sensor system simply needs resetting. Check your owner's manual for the location of the TPMS (Tire Pressure Monitoring System) reset button.
- Put the key in the ignition and turn it to the "on" position, but do not start the car.
- Press and hold down the reset button (sometimes located under the steering wheel) until the low-pressure light blinks three times.
- Release the button.
- Start the vehicle and let it run for 20 minutes to let its computer recalibrate each sensor.
- Turn off the ignition.
3. Deflate and Reinflate the Tires
Some vehicles, like the Toyota Prius, for example, feature a leeway of three pounds or so for tire pressure. If the reset button doesn't work, try inflating each tire to its proper PSI plus three, then deflate all of the tires to near zero. Next, re-inflate all of the tires to the appropriate pressure noted on the sidewall. Don't forget the spare tire—it often has a sensor attached also. Drive a few miles at 15 mph to reset the sensors.
4. Disconnect and Reconnect the Car's Battery
Your car has an onboard computer that checks all the sensors in the vehicle (including the tire pressure sensors) and decides what to do with that information. Just like your computer at home, the computer in your car may occasionally have an unexplained glitch in its system. A quick and easy way to reset your computer is to disconnect and reconnect your car's battery.
- Open your vehicle's hood.
- Find the battery and disconnect the negative battery cable. You will need a wrench to do this.
- Once the battery is disconnected, turn your vehicle on and press the horn for approximately three seconds. This will drain any remaining energy stored in the vehicle's electrical system.
- Reconnect the negative battery cable.
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If the Above Methods Do Not Fix the Problem
It is also possible that your tires are fine, but your sensor is damaged. If so, it may be necessary to take your vehicle to your dealer or repair shop to have the sensor replaced.
A sensor can be damaged during:
- Normal tire service
- Tire replacement
- Brake system work
- Tire rotation
- A CV boot/axle replacement
- An oil change
- A filter change
Additionally, the air pressure gauge may be miscalibrated, or the battery that powers the sensor may have died. In these cases, the sensor will need to be recalibrated or replaced. If you take your vehicle to your dealership or a dealer-recommended repair shop, they will likely be able to fix it in minutes with a scan tool.
Other Concerns and Last Resorts
Sometimes, if the TPMS light comes back on, it may indicate a larger problem. Any of the following may be true:
- One of the tires may have a slow leak.
- The system may have an internal fault that prevents it from functioning properly.
- The wheel sensor may need to be replaced (in an indirect TPMS).
In an Indirect system, if the wheel sensor has gone bad, the ABS warning light will also illuminate. If this is the case, the vehicle needs to go to a certified mechanic. A mechanic can detect and patch the leak or replace the tire. They can also repair or replace the sensor system, if needed. Replacing the system can cost around $1,000.
Maintenance Tips for Avoiding Pressure Sensor Faults
Once the problem is fixed, you probably won't want to have to go through a future malfunction. Following a few simple maintenance tips can keep your tire pressure monitoring system running well. Here's what you can do to minimize your chances of getting stuck with another malfunction
- First, if a tire requires a replacement valve-stem core, choose a stainless steel core. The brass cores corrode. A stainless steel core costs about $2, but a corrosion-damaged sensor can cost about $100 to fix or replace. It's worth investing in the stainless core.
- Second, always keep the cap screwed onto the valve stem. This protects the sensor from water, mud, and road salt damage.
- Third, avoid using aerosol flat-fixer, if possible. It may say "sensor-safe," but it can cause problems if the fixer compound enters the hole through which the sensor measures pressure. If a sensor hole becomes plugged, it may become unable to take readings.
A stuck low tire pressure light can be annoying and distracting to a driver. When it malfunctions, it puts drivers and passengers at risk since it no longer accurately transmits tire inflation information. The sooner you fix it, the sooner you'll be driving safely again. Good luck!
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2017 Kate Daily