BB :

I have a 190 2.3 and I don't have ABS so I'm not sure about your light. I do know that a friend of mine had this problem with his 300e and was told it would be costly to fix it and so he didn't fix it because he decided to sell the car. I never knew what the problem was.

I had the coolant light problem and it turned out that the sensor neded to be replaced. Some people may suggest to try cleaning it first. I just changed it and it doesn't light up anymore.