As said before, there's nothing in the central locking system that will disable the locks in the car. It merely operates the lock stem with vacuum pods. The mechanical force in the automatic locks is pretty weak and is easily overridden with the key assuming something is amiss with that part of the system.

How often do you use the other locks that have now failed? If you have more than one Mercedes, it may be a good idea to verify that you're using the right key. I know it sounds dumb, but it happens even with the best of intentions.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]