It must be refilled via the trans dipstick. If you have the hood of your car open, and you are looking at the engine from the front of the car, it's at the end of the engine block, by the firewall, on the left corner. I believe it is either a black or red round plastic cap. It is probably sealed and will need to be broken. Be sure, if you do do this yourself, that you get the special transmission fluid from Mercedes-Benz!!! Do not put anything else in there. Your transmission is very sensitive to fine particles, fluid amount, and the type of. If I were you though, I would strongly recommend you have it towed to the dealer and have them do it for you... It shouldn't be very much money.... but considering a new trans in your car would run you about $4,000 dollars, I would have it done by the dealer!! Good luck with whatever you do.

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2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)