This has happened a few times to me and here is what I have found. First off my car is essentially like a new car. 2014 E63S with only 6k miles, so everything is as new, always garaged, always perfectly clean. Anyway, I have found that on the times I have received these errors was ONLY when the vehicle was parked straight into the garage. So I believe the guy above who said he’s only gotten it in certain parking situations is on to something. For example if I back into my garage I have never once gotten the message, or any other place. So for whatever reason the sensors/computers don’t always like something. Garage door opener right above, hot water heater and my furnace is just in front of the car. No idea. Anyway, I’ve received alerts for lane sense, active high beams, etc, but they all work perfectly fine and the errors go away.
I have a new main battery, but haven’t changed the aux battery. I thought about doing that, but it has tested fine and these errors are rare, and really a non issue since they still work even after the warning. Like mentioned, I wouldn’t worry about it.
Has your errors only popped up after the vehicle being parked in an exact certain spot?