I have the same car.

What 4matic light are you referring to, the triangle or the lower dash light?

On mine, the triangle lights up upon start up, but not the other one (I am assuming that I need to replace that bulb.) Also, my 4matic works some of the time, but all of the time. The rear wheels have been known to spin.

I doubt that the 4matic is dependent upon the bulb, but that would be an easy fix if that was the case.