Turn on the ignition so all the dash lights come on but don't start the engine.Lock the door using the button on the door handle and then unlock the door (but don't open it) 3 times.Turn off the ignition.Lock the door using the button on the door handle and then unlock the door (but don't open it) 3 times.Turn on the ignition but dont start the engine - you should be able to hear a beep.Lock the door again as before then unlock it (only once this time) - a final beep should be heard.If all goes according to plan your doors should now auto lock when you go over a certain speed (about 5-10mph). This will also auto lock the doors if you reverse away. This mod will be operational until you repeat the above steps to switch it off. It will only work once for each time the car is started though. In other words, if you unlock the doors to let someone out without turning the engine off, they will not automatically lock when you move away again.
