On my 1999 mondeo,Every so often the central locking locks the car on its own.This only happens while driving.

steven waters, April 2006

Hi Ya...my Ford focus also does this,but only in below ambient tempretures i.e when its freezing outside.I'm sure i read somewhere that its either water ingress into the electrical connectors or the door locks themselves at fault.
Sorry i cant be more precise....Gary

Gary, July 2006