I have a C200K which have had the same problem. Yes out where I am at, there are C200K.

Anyway, I took my car to the dealer for a fix considering it have only 3000km on th clock!

Mine was a lose connection from one of the sensor. The sensor that was lose was the one on the brake padel according to the service manager.

Tha pain is that when the BAS/ESP warning light is not on, i.e. after reset by shutting down, the display will say no malfunction. In this situtation, the dealer cannot (sound like will not) perform any diagnostic. I have to wait until the light come on and drive to the dealer right-a-way!

Speaking on the same note, I also note from the manual that this BAS/ESP warning could also be triggered by a low battery problem. When was your battery last looked at! Is it dirty?? Try those first.