TPMS Control Unit Programmable?
 

I've heard rumors that there is at least one available field in the TPMS control unit for a 955 Cayenne that can be coded using a PIWIS for an optional tire size. Anyone know for sure?


Reason I ask is that I'd like to install the factory 21" wheels on my Cayenne, but wish to retain my vehicle's TPMS. Right now, the largest tire size shown in the dash display for TPMS purposes is a 275/40/20.

Am I SOL, or can I have my dealer add the 295/35/21 tire size and related air pressures to my selectable TPMS menu?

You can just tell the cluster that you are running the 20's and it will be fine. For instance, it has no setting for 20" snow tires, but plenty of Cayennes are running them. Just run 38/42 psi and you will be fine.