DIRECT VS. INDIRECT TPMS

The Tire Pressure Monitoring System (TPMS) light came to be as a matter of safety. An underinflated tire is more likely to cause a blowout. The TREAD act passed by National Highway Safety Administration in 2007 was created to hold manufacturers accountable for recalls and designs of the TPMS. TPMS can be broken into major types. Direct and indirect, let us compare and contrast the two.

Direct TPMS:

• Uses pressure monitoring sensors that measure specific pressure levels
• Most provide temperature readings on top of air pressure
• Transmitted directly to a centralized control module where information is calculated. If the pressure is off, the TPMS light triggers
• More accurate than indirect TPMS
• Batteries last about a decade, once the battery is dead the entire sensor must be changed
• Sensors may become damaged while on the road or mounting /demounting tires

Indirect TPMS

• Rely on wheel speed sensors as opposed to pressure sensors
• Needs to be reset every time tires are inflated or rotated to ensure accuracy
• Can become inaccurate if tire size is too large or small
• Uneven wear can make readings unreliable
• Requires less maintenance and programming that direct TPMS over time

While they serve the same purpose, each system requires their own procedures and schedules. Carefully monitoring the status of your tires is the best way to maximize the life of tires and keep yourself safe. If you have a sensor issue, reach out to an ASE technician or auto shop such as Ferber’s tire and auto!