Tire pressure sensors

[kholmes]

Does anyone know what frequency the tire pressure sensors in new cars use to transmit data to the console? Also what is the data stream structure?

Keith Holmes
Henderson, Texas

[haklesup]

Good question, I checked a few how do they work websites but they don't go into those technical details. I searched ebay and there are lots and here is one with 315Mhz printed on the side. Maybe one of these ebay vendors can email you a datasheet although most look to be recovered used parts, a few look like sets. I didn't see any recievers or displays for this data.

http://cgi.ebay.com/ebaymotors/Equinox- ... ccessories

While I couldn't see any data about the transmission method, I would expect that it does not emit any signal if the tire is properly inflated and a constant alarm if it is out of range. I believe this because they don't display actual tire pressure or discriminate which tire is low if the idiot light in the dash lights up. Active signal only when a fault is detected would also save the battery life considerably (which may have to last 10 years). They don't appear to have replacable batrery covers.