My 2007 E550 has about 7,000 miles and 9 months on it. The service indicator has been saying that service is due at 13,000 miles or thereabouts. I just came back from a three-week vacation (when the car was not driven) and now the indicator says Service C is due in 21 days. I am confused about why the service is needed so quickly (as compared to before) and why the indicator is now in days rather than miles.

By the way, this car was an assisted trade on a 2005 E500 that had several problems including repeated sensotronic brake failure. I am happy to say that except for two check engine indicators the car has been terrific!