service indictor reads service g on 2006 Mercedes-Benz E350

what service is needed when display reads service g?

Asked by for the 2006 Mercedes-Benz E350
The maintenance service indicator, help you understand an approximate time required to perform that service. They are Service A-H (1hour for each letter), Service A=1hr... Service H=8hrs.
You may need to get the owners and maintenance manuals here: