So you’re driving when you get a dash-light on from the TPMS, meaning it’s time to check the tires or the sensor. This article and video covers what the tire pressure monitoring system (TPMS) is, and what it means and what to do when the TPMS light is on. Our mechanic Sue also reviews common ways the sensor can break.
The Meaning of a TPMS Light and What You Need to Do If It’s on
The Meaning of the TPMS Light
TPMS means “tire pressure monitoring system.” This system measures the tire’s air pressure and notifies the driver when there is a problem with the system, like having low air in the tires. Manufacturers have been required to have TPMS sensors on 2008 and newer models to improve fuel economy. If the TPMS light is on, it can mean there is a problem the sensor in the tire or with the air in the tires.
What to Do When the TPMS Light Is on
TPMS Light Is on the Dash But Not Flashing
If the TPMS light turns on, pull over and check the air in the tire. Air is measured in pounds per square inch (psi). You can find the manufacturer’s recommend psi on the sticker in the door jamb on the driver side. Use a tire gauge, check the tires’ psi, and see if you need to add air. They may only be a few pounds off.
Read more about how to add air to your tires
Tire Pressure Light Turns on and Then Turns Off
The tire pressure light can turn on if your wheels are fine. If the TPMS light turns on but then during your drive it turns off, there may be no issue with your tires. Sometimes colder weather can drop the air in the tire and give an incorrect reading. The colder air will contract the air in the tire, and this air will expand and raise the reading once the weather warms up.
Read more about why the TPMS light turns on in cold weather
TPMS Light Is on and Flashing
If the TPMS light is on and flashing, that means the computer thinks there is an issue with the sensor. Inspect the sensor, which is located on and inside the tire, and see if the stem is corroded or damaged. You might be able to replace just the stem. If the light is flashing and you can’t tell if the sensor is damaged and don’t have enough mechanical experience to fix it yourself, have a mechanic look at the sensor—it might need to be replaced.
How to Fix a TPMS Sensor
Fix the TPMS Sensor Yourself
Replace the Entire Sensor Yourself
If you’re more experienced, you can replace the sensor with a tire changer, otherwise separating the tire from the wheel will be difficult and is best left to a mechanic. You will also need to calibrate and program the sensor depending on the kind of sensor and the vehicle manufacturer.
Replace the Valve Stem or Seal
Sometimes you’ll have to replace part of the sensor, and sometimes the entire sensor will need to be replaced. If there’s just damage to the stem, the stem itself can be replaced on some TPMS sensors.
Some TPMS sensors have rubber valve stems, and some have aluminum valve stems. If the damaged sensor has a broken rubber valve stem, you can replace the stem without having to replace the entire sensor. If the sensor has an aluminum valve, you can replace the seal on the sensor with a special kit, but you’ll have to replace the entire sensor if the aluminum valve is damaged.
Bring It to a Professional Service
If the TPMS sensor is damaged, bring it to a professional tire service or mechanic so they can repair it for you. If you used tire sealant, let the mechanic know to prevent further damage.
How Much Does It Cost to Replace a TPMS Sensor?
A TPMS sensor can range from under $100 to over $200. They are known for being an expensive part to replace and also a troublesome one since many require programming calibration after they are installed. A universal sensor might cost less, but it’ll be a little harder to program than an original equipment part (OEM).
Some manufacturers don’t make you reprogram and recalibrate, but have another process, such as hitting a button to reset them, turning the key on, and driving a certain speed for a certain amount of time. For other systems, you’ll have to put the number from the sensor in a scanner, and program the sensor per wheel.
How to Prevent Damage to the TPMS Sensor
Ways to Prevent Damage to the TPMS Sensor
- If You Used Tire Sealant to Fix a Flat, Let the Mechanic Know
If you put tire sealant in the tire to fix a flat, let the mechanic know there is a sealant chemical in your tire. When the mechanic removes the tire, not knowing this information could lead to damage and harm, like an explosion.
If you want to avoid risking damage to the TPMS sensor, do not use tire sealant. Tire sealant can also damage the TPMS sensors in the tires. The fluid coats the tire and that chemical can seep into the sensor and damage the electronics.
- Avoid Areas Prone to Inclement Weather, Road Salt, and Sand
Driving in areas like New England that have a lot of snow and rain can damage the sensors over time. The road salt and sand used to combat these elements can also damage and corrode the sensors.
- Take the Tire Apart Correctly
If replacing the sensor yourself, when taking the tire apart, make sure you know the special procedures needed. Sometimes, if you’ve been working on cars for a long time, it can be easy to forget the necessary steps, and this can lead to damage, like cracking and breaking the sensor.
- Don’t Overtighten the New Sensor
Tightening the aluminum TPMS sensors too tight can damage them. When installing the new sensor, torque it to the right specification. Otherwise, you risk damaging and breaking the sensor by not applying the right amount of torque.
Learn How to Diagnose and Fix Other Parts
Follow Instructions in Our DIY How-to Videos
Now that you’ve learned the meaning of the TPMS light and what to do when it turns on, find out how to diagnose and fix other parts with our how-to videos.
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