The question is not about failing but detecting an obstacle and braking. If one system detects an obstacle, stop the car. Even if this system was failing and t

The question is not about failing but detecting an obstacle and braking. If one system detects an obstacle, stop the car. Even if this system was failing and the other wasn't detecting anything. And if one system fail, yes the car should stop if it's not safe to drive with only one of them.