Ahhhhh!!!!!

15 deg morning - cold start. Car starts with high idle, drops, lug lug lug.

Lug lug lug, SES light flashing. Here we go again!

Back in again - to fix both the cold start and the vibrating idle.

Crazy.

Killcrap, your insight has yet to be proven wrong. Surprised that BMW doesn't even want to diagnose the levers with the check procedure.