Hi, Sounds like an interesting issue. I did some research on this and found BMW has issue a TSB (technical service bulletin) B12 21 12. I will see if I can get you a link to view the bulletin. According to the TSB BMW will re flash your engine computer (ecm) to compensate for the poor idle quality. It doesn't mean you have a bad computer, it basically needs to be re-calibrated, which means a trip to the dealer. I would advise you to give BMW a call tell them what your symptoms are, they will likely want to diagnose it (depending on warranty, you may or may not be charged) and more than likely tell you they need to re-flash the ecm. Again I will try to get you a link for the TSB so you have some ammo before going in. If not, you can always use the B122112 reference number, they will be able to look it up that way. One last thing, I'm assuming this TSB refers to your vehicle, without a VIN (vehicle identification number) its hard to tell exactly. BMW has a few different engine codes, and transmission codes. But giving the info you gave me it looks like you qualify!
Friday, December 11th, 2015 AT 6:16 PM