Just to bring some closure to my situation:
I went to my indy shop back in February. They confirmed that the codes were for the transfer case actuator. They tried servicing the transfer case, but the light returned during their test drives. I looked at the BMW TIS and got some good info from another member, but determined it was beyond the scope of my abilities. I believe something in the ABS computer has to be reset after the part install.
Anyway $1100 later, new transfer case actuator and no further problems.