On Fay's Subaru, with 170,000 miles, we get an occasional "Check Engine" light about every 3 tanks of fuel. The code is "Low Efficiency of Catalytic Converter".
By design, however, when that "Check Engine" light comes on, the car TURNS OFF the ABS braking system, the cruise control, and the Anti-Skid system that makes the car stable in the rain.
In other words, "Fix This Emissions Fault or DIE, PUNK!" if the road isn't ideal. There's no technical reason to turn those things off - it's to coerce you into replacing the catalytic converter.
It wouldn't shock me a bit if my "autonomous vehicle" would detect that I had visited a "forbidden" conservative political website and drive me into a utility pole ...