Newbie here! Car is 2016 e350 convertible. Over last few weeks when using my key fob I had intermittent message anti collision inoperative which I read could be low battery charge so drove for 10 mins and message went . Last Thursday message without changing gear consult workshop came up as I started car no warning sound and no check engine light I drove up and down driveway no problems but message still there! Used husbands key and no message at all. Replaced battery in my key fob and it was fine until this morning - same message no warning but car didn’t start - went indoors got husbands key no message and car started fine and I’ve just been out and stopped at 3 places restarted car and everything is fine! I’m so Hoping it’s just my key - can I get it checked anywhere except a Mercedes dealer! Thanks for your help everyone!