My TPMS Light Is On: What Does It Mean?

 

What Does TPMS Mean?

“TPMS” stands for Tire Pressure Monitoring System. A car’s TPMS measures the tire pressure of each individual tire and alerts the driver when the tire air pressure is too low. The TPMS warning light comes on when one or more tires drop at least 25% below the vehicle’s recommended inflation level.

In 2000, Congress passed the Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act. The TREAD Act mandated that every passenger vehicle have an electronic system to notify the driver of under-inflated tires. As a result, all vehicles manufactured since 2007 are equipped with some kind of TPMS system.

You probably see the TPMS light illuminate for a few seconds every time you start your car. The TPMS symbol looks like a cross-section of a flat tire with an exclamation point in the middle. Some vehicles also illuminate the letters “TPMS.”

Read: What All the Symbols on Your Car’s Dashboard Mean

It’s important to keep your tires properly inflated. Under-inflated tires cause:

• • accelerated tire wear
  • poor traction and handling
  • flat tires/blowouts
  • poor gas mileage
  • higher risk of hydroplaning

It’s also not safe to have overinflated tires. Over-inflated tires don’t absorb road impacts well and cause decreased traction and accelerated tire wear.

Direct vs. Indirect TPMS

Direct TPMS is the most common type of TPMS since it is the most accurate system. A direct TPMS takes tire pressure readings from sensors mounted on each tire. The sensors measure air pressure inside the tire and feed data directly to your car’s computer system.

An indirect TPMS, on the other hand, doesn’t measure each tire’s air pressure. Instead, it uses the Anti-Lock Braking (ABS) system to measure tires’ rotational speed and approximate tire pressure levels.

To put it simply: the lower the tire pressure, the smaller the tire circumference, and the smaller the tire, the faster it spins. So by comparing tire rotation speeds, the TPMS figures out if tires are low on air.

Some vehicles’ systems show you the exact, real-time tire pressure of each tire, while others simply alert you when a tire gets low. No matter which system your vehicle has, we still recommend that you manually check your tire pressure with a tire gauge as part of your monthly tire check-up.

What Should I Do if My TPMS Light Comes On?

TPMS Light Comes On Solid

A solid TPMS light indicates that one or more tires are at least 25% below the recommended tire pressure and need to be inflated.

What to do when your TPMS light comes on:

1. If you’re driving, find a safe place to pull out of traffic and stop to check your tires.

2. Use a tire gauge to check the pressure of each tire. The manufacturer’s recommended pressure level is typically on a sticker located inside the driver’s side door. (Don’t use the number on the tire sidewall! That’s the tire’s maximum pressure.)

3. If the tire is completely flat or blown out, you’ll need to change the tire out with a spare or call a tow truck. If the tire is just low on air, stop by the nearest Virginia Tire & Auto for a free tire pressure check or find a gas station with an air pump.

4. The TPMS light should turn off several minutes after re-inflating the tire(s) to the correct pressure.

5. If necessary, have the tire experts at Virginia Tire & Auto inspect the tire for leaks or punctures and safely repair the tire.

If the TPMS light illuminates when you start your car and then turns off later in the day, it was likely triggered by a change in the weather. Tires lose about a pound of air pressure for every 10-degree drop in temperature, so the TPMS light often turns on and off in the fall and spring as temperatures rise and fall.

Read: Why You Should Consider Filling Your Tires with Nitrogen

TPMS Light Flashing On and Off Then Stays Solid

Is your tire pressure light blinking? On most vehicles, a TPMS light that flashes for 60-90 seconds and then stays solid for the rest of the drive indicates that something is wrong with the TPMS system.

Typical causes:

• • Dead TPMS sensor battery
  • Damaged or missing TPMS sensor
  • Damaged tire valve
  • Malfunctioning internal electronics
  • TPMS reset procedure not performed correctly

While a malfunctioning sensor will not affect your tires’ performance, it will keep the system from alerting you when your tires are low.

To get the flashing TPMS light to go off, bring your vehicle to Virginia Tire & Auto and let our tire technicians diagnose and replace your TPMS sensors.

How Long Does a TPMS Sensor Last?

A TPMS sensor is tucked between the wheel and the tire and is powered by a small, non-rechargeable battery that cannot be serviced or replaced.

The sensor’s battery life differs by manufacturer, but they generally start to fail after 5–7 years or 70,000 miles, causing a flashing TPMS light.

Each sensor unit costs anywhere from $50 to $150. And if one fails, you might as well go ahead and have the other three replaced, as they will likely be following suit soon. (Some vehicles also require a TPMS sensor on the spare tire.)

We recommend replacing the TPMS sensors every time you replace your tires. When this service is done during tire replacement, installing the new sensors is inexpensive (averaging $10 per wheel) since the technicians are already dismounting, mounting and balancing the tires.

Never Ignore the TPMS Light

Whether you need a tire pressure check or TPMS sensor replacement, we’re fully equipped to serve your vehicle. All Virginia Tire & Auto locations have state-of-the-art tire equipment and employees with Tire Industry Association and TMPS training. Drop by anytime or schedule a service visit online.