Why do warning lights come on and then go off when starting the engine?

Warning lights illuminate when starting the engine as part of a self-check diagnostic process conducted by the vehicle's onboard computer. This brief activation ensures that all systems are functioning correctly and that the warning lights are operational. If there are no issues detected, the lights will turn off after a few seconds, indicating that the vehicle is ready for use. However, if a light remains on after this initial check, it signals a potential problem that needs attention.