Here's one to keep for reference.....
 

Went out to start the GL550 this morning and it would not shift out of Park. Tried everything - even pushed it back and forth a bit to see if that helped. Nothing. Like other strange, intermittent issues with MB key FOBs and Keyless-Go, I shut off the car, got out, locked it with the key FOB, unlocked it, took out the Keyless GO button and started it by inserting the key. Went into gear like nothing was wrong. Just tossing this out there for future reference for others. And yes, the battery in the FOB is 2 weeks old.

The exact same thing happened ro me twice already. I told myself if it happens once more im calling for service appointment.

That would probably be right about when I use the "panic" button on the FOB.

Solve "it" yourself - I am not a fan of MB FOB batteries made by Panasonic in Indonesia, I import Maxell from Japan by the 100"s...

Yep - Been using those Maxell batteries since day one, since I didn't trust the ones in there when I bought it, even though I have to think that FOB battery replacement would be part of the CPO process. I have had a couple other incidents where I get the Key FOB not Recognized message when it is sitting right there in the console. No biggie - usually a quick lock and unlock pairs them back up. Same thing used to happen on my 2003 E500.

OK....this may not apply BUTTTTT...back when I had my 07, I had the same problem....turned out to be a small battery , separate from the main battery that specifically powers the shift mechanism! They replaced that and the problem never reappeared!!

Thanks blittle - Good call. I will have them check it out at the next service visit or sooner if it happens again.