Central Locking!!

Went out today,all was as normal.When we got there i tried locking the truck,it would click then click again(no indicator flash!) and would not lock.
Found out that the n/s/r passenger door will not lock or unlock with the central locking but will lock and unlock manually.
I can still hear the motor sounds in the door but it's not locking or locking!
So before i take the panel off and possibly make a pig of it.
Is there anyway it's easy to fix,is it something to do with the remote and central locking??

:?: :roll: