For the past twenty years, the automotive industry and research organizations have been aiming to put fully autonomous cars on the road. These cars which can be driven without the intervention of a driver, use several sensors and artificial intelligence technologies simultaneously, which allow them to detect the environment in order to merge the information obtained to analyze it, decide on an action, and to implement it. Thus, we are at the dawn of a revolution in the world of transport and mobility, which leads us to ensure the movement of the autonomous car in a safe manner. In this paper, we examine certain attacks on autonomous cars such as the denial of service attack, as well as the impact of these attacks on the last two levels of vehicle autonomy.