I was driving my 2006 M6 the other day. I shut it off for an hour and then went to leave again, when I started it this time i got all these faults. Engine malf, reduced power, DSC, DBC, and start-off assistance inactive. When I let the car sit over night its fine in the morning, but once i shut it off and turn back on shortly these faults pop. I brought it to the BMW dealer to get the codes ran. They gave me a 2 page list of "possible" sources for the problem. I read about the steering wheel angle sensor so i took apart my steering wheel and cleaned of the inner ring. Also left the battery disconnected over night. The car was fine for 3-4 days, even when urned off then on. Checked the battery and its fully charged but just in case i got a new one but did not change anything. Not sure what it might maybe steering angel sensor or throttle actuators be any ideas? Is there anyway to be 100% sure what the problem is? The dealer gave me multiple codes but I dont know which it could be.