Hi! Beat me to editing my first post. Yes, exactly. I have retrofitted an 05 TCU to my 03 M5 but the coding is incorrect. As the M5 never came with a TCU (only ULF), I am unable to manipulate it properly.
I used a ZCS from a '01 X5 with DSP and was able to code the TCU with NCS Expert with the default settings. The "DSP_PROFILE" setting changed from "1" to "2", yet I still have no audio. My assumption is the the ZCS needs to factor in that the car has a BM53 rather than MID. Unfortunately I cannot change this as no '01 X5s (only year w/ ZCS) supported the option.
To clarify, I had done the same exact retrofit in my past 03 540 with zero issues, plug and play. that TCU had come out of an X5 with matching options (NAV and DSP).