Hi,
I own 2 fob-ed keys, whose batteries were swapped less then 6 months ago.
Sometimes one fob doesn't work at all, so i try the other one, which often works... sometimes it's the other way round..
I think the problem is within the car, as the keys came warm from my pocket and one of the keys was rarely used, so its battery should be fresh..

Is there a way to diagnose that the cat is ready for fob-commands ?

Is there a known issue the the x350 concerning cold weather and fob function ?