The Nuts & Bolts of TPMS

Insight on servicing TPMS.

Asynchronous Sensors

Another, less commonly used Direct type of sensor is asynchronous, which does not respond to a triggering protocol. Rather, they transmit a signal periodically. This design approach was used in the early versions of Beru and Siemens sensors, and in the current versions of those found in many Toyota and Lexus vehicles.

It's important to note that while most sensors work right out of the box, others require pressurization, and must be driven before the sensor will begin to transmit. Some TPMS tools also provide a "listen" mode, so that you can confirm that a sensor is transmitting.

Thomas Kenny is a member of G-5 Electronics, LLC who licenses its TPMS triggering tool technology to K-Tool International (PST brand – and Spectrum Composites, Inc. (TIPS Brand –

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