Engine Management Light

[NSNO]

I wonder if anyone would be able to help in diagnosing an intermittent problem that I have with my car. It is a CLK 270 CDI, with a Brabus D4 remap. The problem is that every so often the warning light comes and then when I stop the car and go to pull away again then the car just starts revving before pulling away. This happened this morning on the way into work. When I got to work I stopped and put the car into reverse in order to reverse into a parking bay and the car would not go anywhere, but just kept revving. I then put it into "D" and the same happened. This seems to happen every so often and then the car will be fine again. Anyone else had this problem and what is it?