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What Is TPMS in My Car?

What is TPMS in my carIf you are a car owner, you may have heard of TPMS but you have probably wondered what the TPMS system does for your car. The Tire Pressure Monitoring System (TPMS) on your vehicle is designed to alert you when the tire pressure is too low. If the TPMS sensor light is illuminated, it usually means that your tires are underinflated. This can cause unnecessary stress on the tires and potentially cause them to fail.

First, check to see if your car is equipped with a TPMS system. When the key is inserted in the ignition and turned to the “on” position, a “low pressure” warning light should appear on your dashboard. If your car has TPMS, here are a few tips to help you understand how the system monitors your vehicle’s tire pressure, and what the various warnings can mean.

Does the TPMS Light Stay Illuminated While Driving?

When the warning light stays on continuously while you’re driving, it means that at least one of your tires has reached the threshold of low pressure. The required pressure level can vary depending on your car, so be sure to check your owner’s manual. This information can also usually be found on a yellow sticker located on the driver’s side doorjamb.

Does the TPMS Light Become Illuminated Intermittently?

If the tires are getting close to a pressure low enough to trigger the TPMS light, fluctuating temperatures might cause the light to turn on and off. Tire pressure can decrease at night in colder weather and increase during the day when it’s hot. Check the pressure on each of your tires and fill them if necessary.

Does the TPMS Light Flash and Stay Illuminated?

When you start your car, the TPMS light may flash for 60 to 90 seconds and then stay illuminated. This usually indicates that there is a problem with the TPMS system, and it should be inspected by a technician.

How Does the TPMS System Work?

Now that you know what the various signals mean, you may also be asking yourself how the system monitors your vehicle’s tire pressure. Your car’s TPMS may operate on one of two systems that are currently being used.

  • Direct TPMS has a sensor mounted in the wheel that monitors the pressure in each of the tires. The sensor transmits a warning to the car’s computer system when the air pressure falls below 25 percent of the manufacturer’s recommendation.
  • Indirect TPMS works in conjunction with your car’s Antilock Braking System wheel-speed sensors. Tires with low-pressure roll at a different speed than tires with the recommended pressure and this is detected by the ABS system.

Does TPMS Replace a Regular Pressure Check?

The TPMS system is not foolproof and should not replace regularly scheduled tire pressure checks. For example, the system may be set up to allow tire pressure to be lower than what is recommended by the manufacturer.

TPMS is a helpful tool that can be used to keep you safe on the road. If your car is equipped with a TPMS system, keep an eye on the warning light and be sure to check tire pressure when you get an alert.