Tire light on? Blame the weather - probably

If you got in your car this morning and were greeted by the sight of an urgent-looking amber light coming from your dashboard, you’re probably not alone.

This warning light, which appears as an exclamation point inside of a horseshoe-shaped symbol, is courtesy of your car’s Tire Pressure Monitoring System, or TPMS.

However, just because the light is on, doesn’t necessarily mean that you have a flat or leaky tire.

Dawn Scott, resident tire expert at Raben Tire’s North Park location in Evansville, says the store gets many phone calls and visits this time of year.

The reason? Changes in ambient temperature and humidity – especially relatively large and rapid changes like those we’ve had in the Tri-State the last couple of weeks – can play havoc with the system’s sensors as well causing actual losses in tire pressure.

“The light has a big exclamation point, so a lot of people see that and kind of freak out thinking it’s a major problem,” Scott said. “Most of the time it’s just because of the temperature changes. Of course, sometimes they have a nail or something in their tire, but most of the time all we have to do is put a little bit of air in there, and that resets the system.”

If the warning light comes on early in the morning, but then goes off later in the day as the temperature gets warmer, you likely don’t have a problem. The system can be very sensitive in some cars and drops of only 1-2 PSI per tire can cause it to alert.

However, if the light flashes, that indicates there is something wrong with the system itself and service is needed.

It is important to note the TPMS, which became a mandatory safety feature in all new cars in the U.S. in 2008, was never intended to take the place of routine tire maintenance. Routine checks with a quality air-pressure gauge and refills when needed are still recommended by the product literature that comes with all cars.

Scott pointed out that it is important to follow the manufacturer’s recommendations on tire pressures for your specific car in order for the TPMS to work properly. Those numbers can almost always be found in a placard inside the driver’s side door.

“A lot of people look at the number of the side of the tire,” she said. “That’s the maximum amount of air the tire can hold. You should never fill it up that high.”