I thought this might just help someone, I woke up yesterday after a cold day and my key fob simply "stopped working" after souring the internet, trying all the tricks..new battery, resetting, reprogramming ..none of which worked.
I simply dismantled the key and cleaned it with rubbing alcohol, dried it and amazingly it started working again.
It might not work for everyone but definitely worth a try.
I do hope it helps someone.