This application discloses self-diagnosis of faults for an assisted or automated driving system of a vehicle. A primary computing system can generate an environmental model populated with objects detected from measurement data from sensors. A secondary computing system can generate a secondary system data structure configured to identify objects located around the vehicle that were detected from measurement data from the sensors. The secondary computing system can identify a fault in the sensors based on a comparison of the secondary system data structure with the environmental model. The secondary computing system also can estimate an amount of time before the vehicle crashes from a vehicle velocity vector and free space in the environment around the vehicle, and identify the fault in the sensors based on the estimated amount of time before the vehicle crashes.