Intermittent Key Fob Issue
 

About once a week my fob for my keyless-go will not register with the car. I can not open the door or start the car without using the key fob. After I unlock and/or lock the car, I can activate the start button. I replaced the battery and no change. Any ideas?

well, that's a problem. Could be a host of issues then. bad key, bad door receiver, battery....

OP, this is a pretty common issue. It happens to me also. I've spoken with three other MB owners who have this issue. I've spoken with two different service advisors who acknowledge that it is a known issue to MB. I read one time that someone had a software update fix the problem. (The problem is not a low battery.)

204/207/212 reference bulletin LI80.61-P-049924, see attachment. Out of warranty, contact MBUSA to approve goodwill repair due to known production software error 800-367-6372.

While you are there, order a 2nd key.

Thanks Konigstiger. I asked my dealer nicely, but they refused :-(
I will call MBUSA

From what I have read that if you press the lock or unlock button on your vehicle three times or more you disable the Keyless go system. The only way to allow it to work is by pressing the lock or unlock button. To re-inilitize the system. Had the same issue with my 14 550. The dealership replaced both batteries in both keys. the car went back then the relaced the antenna, the car went back and then the replaced both keys. I have not had the issue since but read somewhere about the key pressing. I am aware now and have not had the issue since.