I don't know how it works, but the computer might auto-reset itself (as in a computer crash), or I can reset the computer myself while driving at full speed, but the propulsion system still works. The Autopilot system still works (accelerates, brakes, steers itself). Still, other things don't: audio, HVAC, and speedometer... (because the computer screen is blank), but you can use the phone app as a speedometer in the meantime.
It sounds like the essential propulsion system is separate from the infotainment.