Twice neither of our smart keys for 05 e500 will remotely lock or unlock the doors. on 2005 Mercedes-Benz E500

This has only happend twice, but we have only owned the car for 3 months. No diagnostic codes are present, and the locks will still work with the center stack lock/unlock buttons. I don't believe it's the batteries in the remotes because they both will not work when this occurs.

Asked by for the 2005 Mercedes-Benz E500
There are almost 90 computers in this car, so did you check the codes in ALL of them? There is a complete anti-theft system, with its own codes. If you say had a simple scan ( maybe at a parts store? ) without using the Mercedes HHT, then you will not be able to access all the codes. Food for thought.
Thanks for the info. I will take it to my MB mechanic and have a diagnostic check done.