HI Rob
Persistance is a virtue(or is it patience!Both,I think )
Mine is diagnostically fault free,apart from front and rear light registered errors because I have DEPOs and the facelift tail lights,where I had to swap the pin positioning fir them to work .Stupid BMW DIS tells me both my front and rear lights are out and they are all working fine.Maybe its too clever and knows I didnt have specific OE equipment fitted
Other issue I have is a slight lack of power from 1200 to 1800 and I know its the MAF and I have a new Bosch item to fit but been a few months and I havent got round to it yet .TTTT!No errors at all on diagnostics but because its only a slight power loss its not enough to even register an intermediate fault.So whats the point of diagnostics that dont tell you when you got a power loss and misinform you about your lights
Wish i could help you further with your problem.Would sort it out here ,because we would replace all sensors one by one until we found the culprit.
Nice weekend mate