Underinflated tires can lead to tire failure, blowouts, and increased braking distance. Since 2008, all vehicles sold in the United States have been required to be equipped with a tire pressure monitoring system (TPMS).
The systems with tire pressure monitor sensors measure your tire pressure any time the vehicle is moving (they typically go to sleep when the vehicle has been sitting parked for a few minutes), and when the pressure drops below the safe threshold, the TPMS system illuminates its warning light. Powered by batteries, however, TPMS sensors only last around 5 to 12 years.
Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.
Pro Tip: Some early Ford systems and some Toyota systems don’t use tire pressure sensors; they just measure the rotational speed of each wheel. A tire with lower pressure will spin faster, like a smaller wheel, so if one of the wheels begins to rotate faster, those wheel speed TPMS systems will illuminate the light.
Can You Replace the Battery in Tire Pressure Sensors?
TPMS sensor batteries aren’t designed to be replaced. The sensors are typically either built onto the base of the valve stem or are mounted on the wheel, as with some of the Ford sensors that are banded to the center of the rim. Because they are inside the tire, they aren’t exposed to the elements. But sometimes the sensors that are banded to the rim will come loose from their metal band due to centrifugal force (although that scenario isn’t as common as you might think).
Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.
Pro Tip: Tire pressure monitoring sensors don’t typically cost that much, but they do require breaking down the tire to replace the sensor. Note that most DIY folks will not have the knowhow to do this.
How To Replace a TPMS Sensor Battery (If you so choose)
If you’re up for a challenge, you can try replacing the TPMS sensor’s battery, but realize before you start that it’ll most likely be more trouble than it’s worth, and the sensor may not even work when you’re done. It can take a lot of effort, but here are some tips if you want to try it, anyway:
Prepare the Necessary Tools
To replace your TPMS sensor’s battery, you’ll have to get to the TPMS sensor first. This will require jacks, a wrench set, and a TPMS hand tool. Depending on how thick the potting compound around the TPMS sensor is, you might need a heat gun to melt it off.
Don’t forget to get the correct TPMS sensor battery replacement as well. Prepare all of these tools first, so you don’t have to go back and forth looking for them once you’re in the zone.
Remove the TPMS Sensor
Depending on the type of sensor, you might have to remove the tires first to access it and its battery. Most TPMS sensors are directly connected to the tire valve stem, such as valve cap sensors. Other types such as snap-in and clamp-on sensors are mounted on the barrel of the rim. If you aren’t sure where your TPMS sensor is and how to remove it, don’t hesitate to ask a mechanic for help.
Remove the TPMS Sensor Battery
This is where things get complicated. A layer of potting compound seals the TPMS sensor, making it hard to remove the battery. You’ll have to melt the material off with a heat gun or scrape it off with a screwdriver.
In some cases, the battery is spot-welded to the straps of the circuit board. You can gently unfasten them using a screwdriver or needle-nose pliers.
Spot-Weld the Battery Straps
Once you’ve replaced the battery, you’ll have to secure the straps again. You can do this by spot-welding the straps or using solder and flux instead.
Seal the TPMS With Potting Compound
To protect the TPMS sensor, you’ll have to seal it in the potting compound again. This will keep it safe from constant exposure to moisture, vibrations, and heat.
Why You Should Buy a New TPMS Sensor Instead
While replacing its battery is a challenge welcomed by some DIY enthusiasts, it isn’t recommended. A lot of things can go wrong in the process, and all that trouble is hardly worth it when you can just buy a new TPMS sensor instead.
If you still haven’t made up your mind, here are some reasons why you should buy a new TPMS instead of replacing the batteries:
TPMS Sensor Damage
Because the battery is encased in potting material, you’d have to melt or scrape the compound away. All this force can damage the sensor’s components, rendering all your efforts useless. To save yourself from all that trouble, consider buying a new TPMS sensor instead.
Battery Leakage
Melting the potting compound that seals the TPMS sensor can also damage the battery itself, causing acid to leak and damage the device. Because it’s corrosive, battery acid can also burn your skin if you aren’t careful. Getting a brand-new TPMS sensor instead of replacing the battery is the safer choice.
New Batteries Won’t Last Long
Even if you successfully replace the battery, there’s no guarantee that it’ll last long. In most cases, you won’t find any labels on the TPMS sensor battery, so it’ll be hard to find the exact battery type the sensor needs. Because of this, you might end up using a smaller battery that won’t last as long as the original. With a new TPMS sensor, you won’t have to worry about that as it already comes with a fresh battery.
TPMS Sensors Are Affordable
The cost of TPMS sensor batteries typically ranges from $20 to $200. Similarly, aftermarket TPMS sensors can cost anywhere from $10 to $380, which means you can already score a good-quality one for around $60. Given their similar price range, you’d be getting more of your money’s worth with a brand-new TPMS sensor.
Keep Reading: Related Posts
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.
