When you say 'failing' do you mean you can't activate the locks with the fob or with the button on the handle, or with the button on the hatch? Intermittent operation of the fob is usually a bad battery or an antenna for the remote system that has gotten moved accidentally. Intermittent operation of the button on the door maybe something as simple as dirt build up, which might require disassembly of the handle to resolve. I did have a problem with lock actuators on my 2012, but that was from an incorrect installation of the door handle when the car got repainted. The FSM in my sig has some troubleshooting steps that might help.
