How to Reset a Stuck Low Tire Pressure (TPMS) Light
The low tire pressure light, also know as the TPMS system, on your car should turn off when you have filled your tires to the proper pressure, or "PSI."
Sometimes, it just doesn't work though. The light doesn't always reset, sticking you with an annoying amber light, or as with newer vehicles, a constant message on your display that your tire pressure is low.
If you have ensured that the tire pressures in all of your tires are fine, including your spare tire (yes they have sensors too), and the warning light refuses to turn off, here are a few methods you can 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 & Reinflate the Tires
4. Disconnect and Reconnect the Car's Battery
1. Drive at 50 mph for 10 Miles
Probably the easiest method is to drive about 10 miles at 50 mph. Use the cruise control to keep the speed constant. Some vehicles reset the sensors at higher speeds than others. 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 (or 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 re-calibrate 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 the tires to near zero.
Re-inflate all the tires to the appropriate tire pressure noted on the sidewall. Don't forget the spare tire. It'II usually 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 on-board computer which checks all the sensors in the vehicle (such as the TPMS sensor) and decides what to do with that information. Just like your computer at home, sometimes the computer can have an unexplained glitch in the system. A quick and easy way to reset your computer is to disconnect and reconnect your car's battery.
First, 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.
If the Above Methods Do Not Fix the Problem
Sometimes the tires are fine, but the sensor became damaged, and it may be necessary to take it to the 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 mis-calibrated, or the battery that powers the sensor may have died. In these cases, the sensor needs recalibration or replacement. Take it to the dealership or a dealer recommended repair shop where they will likely fix it in minutes with a scan tool.
Sometimes, the light will come back on and that indicates 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 properly functioning.
- The wheel sensor requires replacing (in an Indirect Tire Pressure Management System).
In an Indirect system, if the wheel sensor has gone bad, the ABS Warning Light also illuminates.
In each case, it means the vehicle needs to go to a certified mechanic. The mechanic can detect and patch the leak or replace the tire. They will also be able to repair or replace the sensor system, if needed. Replacing the system can cost about $1,000.
Once the problem is fixed, you probably don't want to have to go through a future malfunction. Following a few simple maintenance tips can keep your TPMS system running well.
First, if a tire requires a replacement valve-stem core, choose a stainless steel core. The brass cores corrode. The stainless steel core costs about $2 but a corrosion-damaged sensor can cost you about $100. 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 because the fixer compound can enter the sensor's hole that allows it to measure pressure. A plugged sensor hole means it can't take readings.
A stuck low tire pressure light can be annoying and distracting to the driver. Its malfunction also puts the driver and passengers at risk since it no longer accurately transmit tire inflation information. The quicker you fix it, the quicker you'll be driving safely again.
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