If your car or truck is newer than 2008, you probably have a Tire Pressure Monitoring System (TPMS) in your vehicle. That’s one of the mandates of the Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act passed by Congress in 2000.
The purpose of the act is to cut down on accidents. According to the National Highway Traffic Safety Administration (NHTSA), 738 died in 2017 because of tire failure. The agency estimates that less than 20 percent of people take proper care of their tires. That makes the TPMS a lifesaver—literally!
You might not give a second thought about a repair or rebuild kit for your TPMS unless you replace one or more of your tires. The question is, do you really have to get one?
What Does the TPMS Do?
The purpose of the TPMS is to alert drivers about under or overinflated tires. Either could cause it to blow out, putting you at risk of losing control of your vehicle. If you see the warning light go on, it’s time to pull over at the next gas station and check your tire pressure. It usually kicks on when it drops below 25 percent of the recommended PSI.
Bear in mind that inflated tires lose about 1 PSI per month just sitting in your drive or garage. Cold weather can tap them even faster.
That explains some of the other functionality of the TPMS. The sensor unit also monitors the temperature and acceleration because either one can directly impact the tire pressure. It transmits all this info via an antenna to the vehicle’s computer.
The TPMS does a decent job at this task. A follow-up study by the NHTSA found it effectively reduced underinflated tires 55.6% of the time. Suffice to say that it’s an excellent safety net that fortunately protects drivers from not doing regular maintenance on their vehicles themselves.
Back to that warning light. If you see it flashing, or on steady, that means the system detects a tire pressure lower than a safe limit to operate the vehicle with. It could mean there is an issue with the system if you inflate all of the tires to the proper inflation the manufacturer recommends, and verify that with a second source such as a tire pressure gauge. Again, it’s something you need to get checked out pronto to avoid getting a flat or wrecking your vehicle.
When Should You Repair/Replace It?
The kit includes a valve stem retaining screw, the sensor, rubber seal, valve stem, washer, nut, and cap. The sensor end of the system mounts to the inside of the wheel and has a rubber gasket to prevent an air leak. Think of a TPMS as an advanced tire stem (valve). It lets air in and out of the tire but it provides you with a lot more information. Like any part, time and weather can take a toll on them, causing corrosion. That’s particularly true if you live in the snow belt.
After all, road salt is the mortal enemy of all things metal.
You can get it rebuilt if one of these parts goes bad. However, it’s not necessarily a DIY project. You’ll need to discount, and mount the tire, and balance the entire assembly again. It’s not an expensive job, either. However, there’s more to the story.
Lithium-ion batteries run the sensor. They’ll only last so long, too. You can figure 5–10 years tops. They often fail quicker on older vehicles. Therefore, routine maintenance sometimes involves a TPMS repair of the sensor itself. However, the entire unit is epoxy-sealed to extend its lifespan and prevent corrosion. If the battery runs out of juice, it’s time for a sensor replacement.
Anything that could affect the sensor’s ability to monitor the tire pressure could cause it to fail and trigger that warning light. It could be something as simple as using an aerosol tire inflator product. That could gum up the works and interfere with its performance.
Tire Replacements and the TPMS
You’ll often hear about the TPMS when you get new tires or you get them rotated. That’s because the mechanics must replace the kit if they have to take off the sensor during the job. As we’ve discussed, the rebuild isn’t a big deal. Some types are serviceable and can be reset if you replace your tires. However, it’s not always the case.
Some OEM sensors can cost you more than you might expect. The good news is that there are also aftermarket units available that can save you some cash. On the downside, they require calibrating by a tech who knows how to use the necessary software. Not all aftermarket sensors are compatible with all makes and models, so it’s best to consult the experts as to which is best for your vehicle.
The TPMS is an excellent tool for cutting down on one of the leading causes of accidents. But like many parts of your vehicle, it has a finite lifespan. As long as the sensor is functional, you can get a repair/rebuild kit when you get a new tire or do routine maintenance. It’s preventive maintenance that will save you headaches in the long run.