Google:

Every device experiences glitches from time to time, whether it’s a cellphone, a computer, or even a simple toaster. Naturally, people often ask us, what happens if something goes awry with the equipment operating a self-driving car? Of course, the systems that power our self-driving cars need to be more robust than your average household device, so we’ve built in many layers of safety and protections. Our goal is to make sure our car can safely operate even if things don’t go according to plan.
 
Our team is focused on making our roads safer, and that includes finding ways to make our car’s internal systems as reliable as possible. On a practical level, we begin with strengthening the most basic components of our self-driving systems — things like connectors and wiring harnesses that enable our hardware and software to communicate.