Those issues are not all related to a fuse; someone is just feeding you a line in hopes of getting the car sold. More than likely you have a speed sensor gone bad at one of your wheels. You can determine which wheel/sensor it is if you can scan the car with a good diagnostic tool that goes beyond OB II and can get into the manufactures codes. The car should scan as a Mercedes 2003 SLK 320 if it is not a STR6 supercharged model: if it is supercharged you can scan it as a 2003 Mercedes SLK32. Both are on the Mercedes R170 platform.

Wheel speed senors are not too expensive, but they are specific as to which wheel they fit on. Enjoy the ride.