2002 ML500 both keys lost sychronization
 

Hi guys!!!

My 2002 ML500 key remotes, that were both previously working fine for years, no longer will lock my doors. There is also a warning audible beeping tone that comes on whenever I turn the engine off after driving the vehicle or whenever I open the unlocked doors. Also, I tried to manually lock the doors by prying the plastic cover off of the driver's side door key-hole (which I have never used before) and inserting the key, but it will only lock the drivers side door. On another note: While the vehicle is running, I can lock the doors with the center console door locking switch and they all lock like they've always have.

Any insight into a resolution would be greatly appreciated.

Thank you all in advance

I too replaced AAM (~$700 indie) in my 2001 ML55 to get the remote key functionality back. It wasn't functioning for nearly two years.

Convenience of remote lock finally beat our my thrifty nature.