My first limp mode experience. Holy crap...it sucks. At least on mountain highways, where I do most of my driving. Funny this was, there was nothing that stood out about this happening yesterday - no excessive loads, not crazy cold. It went away after about thirty minutes, by which point I was home anyway. iDrive warning and limp mode went away, CEL remained.

Got a friend to read (and reset, to see what comes back) codes, got 4530 and 4C83. Anyone have any insights?

Well...I can’t resize the ETHOS screenshot. Codes are “charge air pressure control deviation” and “exhaust back-pressure before turbocharger, plausibility.”