View Here : Mercedes B Service Checklist
Required Service B for Vehicles MY09 and Newer. Service B is when our highly skilled technicians do what they do best. With comprehensive training under their belts, as well as the use of the latest diagnostic tools and tests, they can help make certain that your Mercedes-Benz vehicle is running at optimal performance.
Since this year the b service takes about twice as long - 4 hours as to 2. They check a lot more now, and fix more things. Probably a result of Knight taking over, but it is one of the good changes.