Tag Archives: TPMS

Always on Guard (TMPS)

One of the most important things you can do to keep your vehicle running safely is to make sure your tires are properly inflated.  If one or more is vastly over- or underinflated, that has the potential to cause major handling problems and may result in a dangerous accident.

All vehicles in recent years are equipped with Tire Pressure Monitoring Systems, or TPMS.  One system uses small sensors in the tires that continually check the pressure in each tire.  That sensor sends a signal to computers in your vehicle which turns on an instrument panel light warning of low pressure when at least one is very low. Or it may update a numeric reading on your instrument panel which gives you an approximation of how many PSI (pounds per square inch) of air is in each tire. 

Another system works with your antilock brake system to measure the size of your vehicle’s tires.  When one wheel is going faster than another, it will spin faster. A computer sees that and alerts you that tire’s diameter is smaller than the others and therefore must be underinflated.

No matter what system you have, it’s also helpful for you to know how much pressure each tire is supposed to be inflated to.  You can find that on a label on the driver’s side door sill. In addition, the TPMS system should not be used as a substitute for checking your tires with a tire gauge since the TPMS accuracy usually isn’t quite as precise.  Keep in mind that tire sensors can fail, so each system acts as a backup for the other. 

Since many vehicles these days don’t have spare tires, it’s good to know that your TPMS can warn you if you have a leak in one of your tires.  If you get a low-pressure warning, many systems will tell you which tire is low, so you can do your own visual check.  Often you can see if you’ve picked up a nail or a screw if it’s sticking out of the tread or near the sidewall.

Being able to receive an early warning from your vehicle of abnormal tire pressure may give you a chance to safely drive to a service center before your tire slowly goes completely flat (which can ruin the tire and badly damage the rim). It also may ultimately prevent you from being stranded somewhere with a flat tire or, most importantly, having a sudden blowout on the road. 

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com

The Truth about Tire Pressure (Tire Inflation)

Most light vehicles (under 10,000 pounds/4,500 kg) in North America sold from 2008 model year on have a feature that many people are confused about.  It’s the tire pressure monitoring system (TPMS).  You may have some experience with it yourself if you own a newer vehicle.  Vehicles with TPMS have sensors in each tire that are supposed to warn the driver when tire pressure gets dangerously low.  That’s important because tires that are significantly under-inflated can cause very serious accidents.

Unfortunately, many drivers think the TPMS does all the work keeping track of tire pressure. To them, as long as the warning light or gauge isn’t giving a warning, the tires must have the proper amount of air pressure in them.  That’s not the case.

Tire pressure monitoring systems aren’t all created equal.   Some give you a digital readout of the pressures in each individual tire.  But many simply have a warning light that looks like the cross section of a tire with an exclamation point in the middle.  If you don’t know what it is, it’s because it’s not instantly recognizable as a tire.  In fact, one company that makes TPMS, Schrader Performance Sensors, surveyed drivers.  Their study showed that more than 40 percent of drivers didn’t know that that warning light was. 

One out of 5 of the drivers who did know what the light was only looked at their tires after the light came on to see if they could see any that needed air; they never checked them with a tire gauge or had someone else do it.  Ten percent of them didn’t do anything when the light came on.

In most vehicles with TPMS, the warning comes on only when the tires are more than 25% underinflated.  The American Automobile Association says that’s under the pressure you need for safe vehicle operation.

The bottom line is once a month you should make sure your tires are inflated to the manufacturer’s recommendations.  That means each tire should be measured with an accurate, external tire gauge.  To be confident you are getting a correct reading, take your vehicle to a reputable service facility where their equipment is calibrated and they know what they’re doing.

Severely underinflated tires can contribute to an accident that kills or severely injures people.  The idea behind TPMS is well intended, but the system was never meant to replace regular inflation measurements and maintenance.  Periodically have your tires checked for proper inflation.

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com