My wife called from the grocery store in town 10 miles away and told me she couldn't unlock her 99 XK8. I drove in and found that the fob buttons cause a beap when pressed but nothing else. Inserting the key in the door lock and turning to the left causes the same beep. turning it to the right does nothing. I can unlock the trunk with the key. Jumped the battery and no change.

If anyone can shed some light on this I'd be most grateful as a 20 mile round trip to try the same things I've already tried is aggravating and expensive. I need some new ideas.

 

Remove the negative battery terminal and touch it to the positive for a few seconds. Then reconnect the negative terminal. Wait about a minute and retry the locks.

If this works, get your battery load tested ASAP, it may be starting to fail.

You will need to reset the windows after this process (all the way down, hold till it clicks, all the way up, hold till it clicks).

 

Update, shot some WD-40 into the key hole and worked the key back and forth and it unlocked. We'll try the fob functionality when she gets home.