Originally Posted by Ethan

I had that on my 2002 C240 it wasn't a bulb but a sensor for the headlights as I recall, I need to chk the dealership work order, which I can do tomorrow.

But I would chk to make sure no bulbs are burnt out first like advised above.
I think your car actually tells you which bulb is burnt out on the dash display when it is a bad bulb.