Symptoms were similar to my 2000 C280, but different engine so this may or may not help.

As suggested, it was the crankshaft position sensor near the fire wall.

My symptoms were a random no start, whether cold or hot. Nothing to do besides waiting until the car's mood changed and it would start and drive normally until the next attempt at a start. This progressed to a random shut down while driving. Again no rhyme or reason to starting again other then just waiting a bit and trying to start.