I dropped my car off last monday with similar issues. DSC/DBC/reduce performance/increased emissions (which came on later in the day). It had at the time of drop off about 15010 miles so I was just about to turn it in anyway, but they had it for a week I got it back Friday afternoon(last night). Good thing was I went out of town monday right after I dropped it off, and got a call that it was ready for pick up on my way back in to town. So no time lost I guess. My dealer said the issuse was the same as yours so, at least they are on track with what it is. You should have it back in no time.
08 E92 ///M3 Alpine White Fox Red Premium/Technolgy