The central locking switch is a two-way switch that is located in the door trim and allows the user to lock or unlock the door by pushing it. This switch can sometimes have an illustration on it with a closed padlock and an open padlock to show the user which way to push the switch to operate.
In a basic setup, the central locking switch sends power to the actuators to control the locking system. However, in a more complex setup, such as those where there are multiple ways to lock and unlock your vehicle, an on-board computer called a body controller will control the power. It also controls many of the functions of a vehicle, including the amount of time the interior lights stay on when the vehicle is started. It also gives you warnings that you’ve left your lights on or if you’ve left the keys in the ignition too.
If the central locking switch fails, it’s most likely due to a wiring or electrical fault in the central locking system. This could mean that the doors would be unable to be unlocked, or alternatively will not lock causing a security issue.