Tire Pressure Monitoring System
What is it?
TPMS is a monitoring system that lets the driver know if they have a flat tire or if the tires are low on air.
There are 2 types of TPMS.
- Direct TPMS- more expensive, more accurate, doesn’t have to be reset after filling the tire or replacing tires. Battery tends to last a decade. Once the battery goes they need to be replaced, about every 10 years.
- Indirect TPMS- counts rotation of tire against the other tires. Under-inflated tires need to rotate more to keep up. Does not use a pressure sensor. Has to be reset after filling tires. Not as accurate. Making a comeback as technology improves. If ALL tires are under inflated by the same amount the TPMS alert won’t be triggered.
TPMS came about in the 1980s in European luxury cars and became mandatory in the United States in 2009 for light passenger cars. The thought was that it would decrease the amount of accidents due to poor tire care and pressure. All cars 2007 or newer, it has TPMS. As per federal regulation the TPMS must signal when there has been a loss of 25% of the recommended tire inflation pressure.
How does it let you know your tire is flat?
Dashboard hieroglyphics: Which Hieroglyphic is for your flat or lowly inflated tire? The symbol is usually a cross section of a tire with an exclamation point. Or parenthesis with a bumpy line at the bottom and exclamation point in the center. Your psi or pounds per square inch is under the recommended threshold by 25% to signal that your tire needs to be re-inflated.
Safety Fact: If your tires gets 5 psi or lower than recommended threshold it could cause a blowout. As your tire deflates it loses stability and heats up much faster trying to rotate fast enough.
Poor tire care causes almost half a million accidents a year. Don’t be a statistic!