Home What is TPMS? How TPMS works
What is TPMS?

How TPMS Technology Works

There are two different types of TPMS—Direct and Indirect. Both systems alert the driver when any tire becomes under-inflated but their implementation is different.

Direct TPMS uses pressure sensors located on each tire to measure its air pressure. The system sends data in real time to an instrument cluster that alerts drivers when air pressure drops 25 percent below the recommended levels. These systems are able to accurately identify under-inflation in a single tire or all of them.

Indirect TPMS does not use sensors but measure tire air pressure by monitoring the rotational speeds of each tire. Under-inflated tires tend to have a slightly smaller diameter than a tire that is correctly inflated. The readings on these systems are not as accurate as the Direct type.