Has anyone experienced a PSM Failure message followed by a Stop/Brake Failure, I used to run 22" wheels but have replaced them with 20" now, also replaced lower and upper arms and bushings, speed sensors appear to be working fine, any ideas?
The PSM failure message normally comes up any time you disconnect the battery. Just driving it around the block should clear that. Did you reset the wheel size in the TPMS? There is plenty of information in a number of places on the Web if you Google Cayenne PSM.