This problem has been going on for two weeks. Basically we swapped two DME's and CAS with keys from good F10 M5 to the bad F10 M5 and car started and idle smooth. Once original DME were installed back we had many issues with DME2 (driver side) so we knew this was bad DME.
I followed the videos from Microtronic site on F10 DME swap. ran into issues but support assisted, with ISN read problems. Not everything shows up in these videos when working on actual car. That I am learning the hard way.
Anyway we were able to get ISN updated on both donor DME, however the nightmare started when DME2 needed to be coded. That's when I get the following:
ONLINE PROGRAMMING: Module rejecting to switch to required mode Reference 830c.
Now I switch to ISTA/P for attempt to program, however ISTA/P complains it needs "ENABLING CODES for "Max engine performance DME2" and same for DME1
Support then suggests to use ISN boot and perform work hours reset. At this point my customer is so upset he ships DME to a tuner whom drills a hole in DME and uses DimSport tuner tool to read the entire DME contents (cloning the DME) and writing back to this problem DME2. I did not this this was good because you are doing something similar like a hard drive cloning that has a virus inside. Issue will just mode to another DME.
Yesterday they installed the DME and same issue car starts and DME2 has same fault and idles very rough. They just completed a full ISTA/P programming at BMW and same problem. Now I will attempt to finally get a shot at doing the work hours reset. and then code the DME.
I check another forum and found that mentioned the hours reset and those folks use another tool, but AutoHex is able to do same but much easy. I will get this DME2 back and attempt to do this on it and will update this post on progress.