The central locking control unit is used to lock/ unlock all of the doors in the vehicle. It is operated by pressing a button on your vehicle’s key or fob. Some keys or key fobs have a separate button to unlock and lock the boot. Otherwise the central locking control unit will also lock/unlock the boot when the other doors open. 

There is one master control unit for central locking and another unit for each of the vehicle’s doors. These are mounted under the vehicle’s door trim and attached to the master control unit which is powered by the 12v battery.

If a central locking control unit is showing signs of failure you may find that the central locking on your vehicle works intermittently. This suggests that there is a problem either with the wiring or electrical components of the unit. If left without repair this could cause a complete failure of the central locking control unit, which could leave you unable to fully lock the vehicle, leading to issues of security. Alternatively, all of the doors in your vehicle could lock, meaning you can only access the vehicle by using the key.