Picked up my 2021 M3SR+ back in January. Here in Winnipeg we can get down to -30C no problem. A couple of weeks ago after preconditioning the car for 20 minutes, I received a climate control error and it would only blow out cold air. Took it into the shop and they replaced the whole super manifold.
Fast forward to today, -32C out driving down the highway it starts blowing cold air out, the windows frost up and for the rest of the drive I could not get the heat back on.
Called the tech and they said there were no errors and that the cold may have overwhelmed the system. That tells me that the heat pump system can’t handle cold weather. At this point it’s a safety concern to me and Tesla should be doing a recall on the heat pump. I don’t feel safe driving the car anymore if the heat will just give out after a while.
TLDR; 2021 M3 heat pump was replaced, still can’t put out enough heat while highway driving.