Ferrari Mailing List: Re: TPMS; was: Ferrari fear and other myths

[George (ygpz4re]

Fellow Listers,

Perhaps someone much more knowledgeable than me can give a "TPMS 101" lecture?  My understanding is that not all systems utilize any sensor in the tire, but instead use the rotational speed of the tire (via the ABS sensors) to compute tire pressures relative to the other tires (and their respective rotational speeds) and when the system was "reset".  My wife's former Passat had a similar system, I believe with no sensors in the tires.  It would turn on the tire pressure warning light when the pressure had dropped by 3 or 4 pounds (turns out there were two punctures - nail and something else - so we had several recent experiences with the light, resetting the pressures, and resetting the system).

I'm open to corrections here....

Thanks!

gp