The module that controls the mirrors and the steering column is the MSC module (Mirror/Steering Column) N32/9. It is in direct contact with the L. Front ESA module (electronic seat module). I say this as I'm not sure they have separate self diagnostics. It would be nice to inquire to see what the controller thinks of matters.
Short of such access one might be able to reset the MSC controller by pulling fuse 30 in F3 and holding it for a few seconds before replugging. Doing this will loose all memories including your settings. Check the owners manual for the initializing instructions if necessary.
Bosch Master, ASE Master, L1
33 years MB technician