Whoa....many thanks zip439. Your reply has sent me in a new direction. My XF spends most of its life locked in my garage, so I leave the car doors unlocked, with the battery disconnected. I can't remember the last time that I actually locked the car - several years!!! Anyway, I just went to the car, key in hand. Now, the battery IS connected, so I tried locking the car with the remote. Nada! The turn signals flashed 3 times but the car didn't lock. Pressed UNLOCK - got a single flash of the turn signals. I assume this is correct? But the central locking did not operate. Then, the penny dropped - I had removed fuse 9 to reduce parasitic drain. Popped that fuse back in and the central locking worked fine. Not "chirping" though - probably 'cos I removed the alarm siren? I checked under the tray in the trunk (aka "boot") and dry as a bone - no surprise there since my car has not seen rain for about 6 years....It's a coupe - maybe that's why it's dry - and I've washed it only once since I bought it! :-)