Have replaced the batteries with new ones in both keys and when it's not starting, believe me it won't start. My XF is not my daily driver but for the past 10 days I've been trying to take it out every day. Starts perfectly for 5 days and then on the next day/evening it won't start. Then it starts perfectly for the next few days and then the next time it won't start. It is beyond annoying. I have been forced to limit my driving to giving my kids a ride and dropping them off and returning home, daytime driving, staying close to home, etc. I can't go on long trips or take it when I have a lot of stops to make because I do not want to be stranded somewhere. Don't get me wrong, I LOVE my XF and when it's running it runs GREAT. It's just that I never know when it's not going to start. Today I'm meeting a friend and heading out to the country; a perfect day to take the XF but I can't/won't. If it doesn't start when I try to return I am screwed! And if I have it towed to the dealer, they will get in it in the morning and it will start right up. "We don't see any problem..." Grrrr...