Need some help. I bought my 2008 Mercedes Benz C350 from the dealer last year at 13,000 miles.

The light came on for B1 service at around the 18,000 mile mark and I had only driven the car for 5,000 miles but the Dealer told me the last service was done about a year ago at 10,000 miles... I got the oil changed last week and the dealer told me to get the B1 Service for about 500$.

My question is, Is this service necessary or a dealers way of making the MONEY? Car to me rides excellent and low mileage ... help please??

 

According to your service manual the A & B service indicators alternate every 10,000 miles. They are mostly fluid and filter changes & one or two other things; which frankly you could do yourself. It seems your reminder kicked in at 18,000 miles & will count down till you reach you 20,000 limit then will remind you every time you turn on the engine and will start counting how many miles over the 20,000 you have done.
When you had the oil changed, was the computer reset to count another 10,000 miles? That seems to me where you made the error; that oil change was unnecessary. You are uning Mobil 1 Synthetic 0W 40 European Formula (I think that is the correct spec, I'm not in my garage)
For my C230 Kompressor, a B service is about $300.

Good Luck!