I suspect MB DOC is correct on this model not having a BM (Base Module). A basic description of what the BM does is distribute power to other modules and protect the modules it provides power to from overvoltage conditions (voltage spikes).
If it had it, it would be on the passengers side of the vehicle towards the rear of the engine bay inside what is called the control module box. On top of the BM is a small plastic window which can be flipped open (hmmmm, maybe it's a door not a window?) and there is some fuses located under that door. I've seen instrument cluster components go dead from a blown fuse in the BM, and also can be the source of other various problems, such as a diagnosis computer (mechanics diagnosis tool) not being provided power from the diagnosis plug on the vehicle.