i have 2001 ford focus estate the problem i have is i cant lock all doors with key fob unless i manually lock the passenger side door first i can then use the key fob to lock all doors, when opening with the key fob it will open all doors except for the passenger one but if i open passenger door with car key it will open all doors. anybody help on a fix. cheers

Sounds like the locking solenoid on the passenger door is at fault. If its providing an incorrect response or reading then the car wont unlock.

Basically the Central Locking Module sends a signal to all doors. If the are all closed and in a state to lock, they do, however, if you open a front door and try it, it fails. This is because the main doors are not able to lock and thus negates the ability of the central locking module. If you leave all doors closed except a back door, the car single locks all doors now and when you close the rear door, that single locks also.