Hi
I have a 2006 x type estate and am having problems locking.
When i use the fob or key to lock the car it does lock but the horn beeps twice as though a door is still open and the interior light stays on
I did diconnect the battery for an hour and when connecting again it all worked as it should. 10 hours later same problem car alarm went off and had to disconnect battery overnight again so interior light went out and did not drain battery.
After reading several posts it seems like a faulty lock but how do i know which lock

 

If the interior light stays on/horn beeps it thinks there is a door open,The door switch is either faulty,wire broke.
Get in the car shut all the doors then try to manually lock the doors, It should NOT let you lock the door, if you put the key in the ignition the fob is useless. but you still shouldn't be able to manually lock them either.Next when you drive above 5MPH they should NOT try to lock, symptoms of a faulty door switch,wire,connection. Also put the key in drivers door with the window open,door shut, hold it for a min. in the lock position to see if it will shut. If any of these operate it could be the controller, but most likely a switch/ wire ect,

 

I had a similar issue and found that my passenger door lock actuator was out. This is a fairly easy repair as long as you have the right security bits and have the replacement part. I bought mine used from car-part.com for about $50 with $8 shipping if I am remembering right. If one of your actuators is dead, it won't lock at all when you lock your door. This makes finding the culprit actuator easy because you just lock your car and then pull on each handle to see which actuator went out. If only one of your doors is open then that's the door with the faulty actuator. If all or none of your doors are open then follow billbjork's advice. Hope you figure it out! It took me about 2 months to finally figure out why my locks were being weird.