There is a inertia sensor fitted that will prevent the doors centrally locking or if the doors are locked will unlock them in the event the vehicle the receives a sudden impact ie. in the event of an accident.
When the inertia switch operates, the hazard warning lamps flash, central locking is inhibited the indicators will flash for a minimum of 30 seconds or untill the system is reset turning the ignition on and off.
Actually you saying that once it has happend the central locking doesnt work and I have to start and stop the ignition so I can lock the car.
Any tips on checking the wirings? earthing? sensor?