A vehicle having a control element for the speed, acceleration or direction of the vehicle, a computing device to generate a command in autonomous driving of the vehicle, and a command controller coupled between the control element and the computing device. In response to the command, the command controller initiates a test of a portion of the memory of the computing device. If the portion of the memory passes the test, the command controller forwards the command for execution via the control element of the vehicle; otherwise, the command controller blocks the command and/or issues a replacement command for the vehicle.