Circling back to this. I have code 5D65 stored, with the occasional dynamic drive malfunction on startup. (turn off, and back on, and the malfunction warning disappears and the car drives normally) This code relates to the position valve in the block.
Its a very similar system to the E60 and the 7 series. I found this
Resource -Everything you didn't want to know about your Dynamic Drive DIY Valve Block - Bimmerfest - BMW Forums
I'll be ordering a used block from ebay and swapping, if bleeding and refilling the system does not fix it. Rheingold has the procedure for recommissioning the system if you change out a part, its a little convoluted