Tire pressure monitoring systems have been mandatory in new cars manufactured in the United States since fall 2007, meaning that the first of these cars now have reached the ripe old age of seven -- and the battery-powered devices are designed to last somewhere between seven to 10 years, according to AAA Carolinas.
As the batteries die, vehicle owners must choose whether to replace a system that automotive repair experts say tends to be underestimated for its safety benefits.
The tire pressure light on the dashboard is "second to probably only the seatbelt light indicator in regards to safety," said Scott Cook, tire manager and trainer at Gerald's Tire & Brakes in Summerville.
"If you ignore it, as a tire loses pressure, it increases in heat, which causes the tire to break down," he said. "If you're traveling interstate speeds and that occurs, it becomes difficult to control. That light's there for a reason. It means you've got a problem. It's going to leave you stranded or, worst-case scenario, cause a wreck that could result in a fatality."
But some customers view the system repair as an investment they don't want to make, especially on high-mileage cars, said William Stewart, service manager at Volvo of Charleston.
"They ignore the light and just check their pressure regularly," Stewart said. "It's a great system and can prevent an accident or blowout, but it's just another feature that, from a financial standpoint, will cost money. Customers have to make a decision of whether they want to put a new one in or live with it inoperable."
The price to replace the sensor varies based on the vehicle and what's involved in resetting the system, and car owners can expect to pay anywhere from $20 to $200 for parts and labor, said Stewart and Cook. Replacing all four sensors at once could run hundreds of dollars.
Cook said he hasn't seen an increase in failed tire pressure monitors, but he's not surprised.
"It really just depends on driving habits," he said. "We see some cars that the batteries will die sooner, and some will last longer."
Joella Morfin-Kerr of Charleston has chosen to live with an inoperable system. "It's nice to have the system back up those feelings that the tires are safe or not," Morfin-Kerr said. She said the system on her van alerted her when she had low pressure because of a nail, but that the light wouldn't reset even after the problem was fixed.
"It remained on the dash haunting me for miles, so I carried a manual tire gauge to check pressure," she said.
Tire pressure monitoring systems aren't new. They've been an optional feature on some models since the 1980s, starting with European luxury cars and reaching some U.S. models by the '90s.
But the pressure mounted to make them mandatory after accidents in the late '90s involving the separation of tire tread because of low air pressure. The system's inclusion in vehicles became federal law as part of the Transportation Recall Enhancement, Accountability and Documentation Act in 2000.
"In the past when you had something wrong with your tire, you rarely knew it unless you went out and checked the tire by yourself," said Tom Crosby of AAA Carolinas. "People today have no idea what the pressure in their tire is and don't take the time to go out and get a gauge. In this case, this is replacing our laziness with a mandatory system."
Carol Privette agreed.
"How many regularly check tire pressure? Oil? Rely on auto sensors?" she asked on Facebook. "I think the majority rely on panel warning lights. I do."
Tire pressure monitors are among the dozens of electronic systems on modern cars that many drivers view as another thing to potentially break, but Stewart said it's not that they're cheaply made. They just can't go on forever.
"Batteries in general are limited lifespan, and wear items -- brakes, windshield wipers, tires -- are just other components that need to be maintained," he said. "Nothing on a car is going to last forever. Safety is the number one reason to get them replaced."
Stewart recommended that vehicle owners without a working pressure monitoring system check tire pressure at least once a month.
If the safety benefits don't persuade people to check their vehicle's tire pressure, said Stewart, maybe saving money will: Proper tire pressure translates to more miles per gallon.
What about that light?
The tire pressure warning light on the dashboard looks like a horseshoe with an exclamation point inside. It lights up when one or more of the vehicle's tires is 25 percent below the manufacturer's recommended pressure.
When the system cannot read one or more sensors, a malfunction light may appear in the form of a "glowing" horseshoe symbol or the letters "TPMS" for Tire Pressure Monitoring System. Check your vehicle's manual for more information.
Copyright 2014 - The Post and Courier, Charleston, S.C.