Three problems related to battery dead have been reported for the 2009 Mercedes Benz C300. The most recently reported issues are listed below.
Eis steering lock battery fail. $12 battery dies and eis stays in lock position key doesn't respond to ignition switch or car unlocking doors.
Taraka recall. Smart key not being recognized , vehicle dead need tow truck to dealer very expensive ,had battery but all dead cost $1600. 00 plus on a 72000 mile vehicle. Also front sway stabilizer bar need total replacing (dealer part only) since its making noise. Bushings cannot be changed like others the whole bar needs to be purchase at dealer with bushing vulcanized to it. On the Smart key the vehicle was stationary thank god.
I bought my Mercedes Benz and notice that my tail light and the light on the front of the car will turn on by itself while my car was parked in the morning my car battery will be dead needing a charge. I had a recall from Mercedes Benz dealer and I took the car to the dealership and supposedly they fix it and the car had gotten worse. It had burned the harnesses and fog harness, while I was driving the car was acting like shutting off the radio and ac will start shutting off and turning on at the same time while I was on the highway on my way home from work. Right now my car only have working the high beam. I been getting a lot of recalls for this car but really it seems like I'm loosing my time .