You can also call 1-800 FORMERCEDES to inquire about your car's symptoms. Over the phone, a service representative will try to coach you through getting back on the road. It's free.
Mercedes-Benz USA, Mercedes Care, Client Care, 1-800-FOR-MERCEDES
http://www.mbusa.com/care/client-care/1-800-for-mercedes.do
(1-800-367-6372)