I have an XF Lux.diesel. 3 ltre 2010. Both my key fobs have now stopped working. They became less and less efficient and I kept putting new batteries in both of them and now have stopped working altogether. Have to use key to open and lock car.
Have heard could be poor car battery condition. Doesn't seem to be a coding issue as they just seem to fade and fade.?
Anyone have any solutions before I spend loads of money on the wrong thing?

 

Just went through this with wife's, 09. Had to replace keyless module and antenna. Didn't completely fix it, took it back, they found a loose connection in drivers door which would stop it from completing the circuit. They also replaced the backs of the key fobs, to hold the batteries better. We also got "no smart key" message. would not unlock car, would not start car, if we unlocked the car with the key, the alarm would go off. The cost was around $750.00 for parts and labor. Fresno, CA

 

You didn't give a no problems selection.

 

Exactly, I have had no problems (as he reaches out and touches wood!).

 

In a related issue; Our XF only had one key when we bought it, so I purchased one online from China. Although the electronics work fine, the housing does not fit the dock on the lower left side of the dash, so I'm hoping that a dead FOB battery does not strand me somewhere sometime.

 

Uh, put an extra $5 battery in your glove box?

 

If you still have the facory installed main battery, then it's time to replace it.
About your keys - when you replaced the batteries in bothe keyfobs, the KVM module lost connections with keys, now you should visit dealer or find someone who hase fullworjing SDD and programming keys again.

 

I replaced the batteries in mine a few months ago and noticed they were behaving erratically, often not starting the car due to smart key not found or once i also had the issue where the doors wouldn't open and using the metal key set off the alarm. Then one day i decided to squeeze the fob when starting and it worked fine, that made me realize the battery was just not in full contact with the metal prongs inside the fob. Opened it up, bent the prongs upwards a bit, and it's been flawless ever since.

 

did u go to the dealership to make the fix? Trying to get a sense of cost as I am having this same issue.