I have an annoying problem with my 2001MY XJR. The key fob will unlock the doors, it will pop the boot, it will make the headlamps flash....but it won't lock the car...I now have to do that with the key. Used to work fine.

I have a spare key fob and it has the same problem.

I have put a new battery in the fob and that has not made any difference.

When I press the lock button on the fob there is no response...not a chirp, not a click from the lock solenoids....nothing.

Maybe un-related, but a couple of times when I've left the car idling for many minutes it has cut out; and twice when starting the car it has fired up and run fine, but then my knee has bumped the ignition key and again the engine has cut out...always re-started fine.

Any (polite) suggestions welcomed. Thanks.

 

Sounds like the contact for the lock button needs cleaning. Us a coin or other appropriate tool to snap the case open. A little alcohol on a cotton swap or small piece of cloth should clean it up.

 

Lubricated the lock cylinders on door/boot/ignition using penetrating oil (WD40) - no difference to the problem but those little latches on the locks clearly needed a bit of tlc.

Opened up and cleaned the accumulated filth and grime from inside both key fobs - amazing how much grunge builds up in those rubbers over 12 years. Cleaned the switches with some penetrating oil (WD40) and a cotton bud...there was a lot of verdigris on the switches. Then a dab of 3-in-1 light machine oil on each switch.

Now one of them works well and the other sort of works (but you have to press the lock button pretty hard and hold it for a second or two).

All in all a good fix - and thanks very much for your help TestPoint.

Happy Motoring!