Check engine light flash then steady

Your vehicle’s computer system has self-testing capability. When the computer senses that there is a problem with one of the components or sensors it stores the correspondent trouble code(s) in its memory and lights up the "Check Engine" or "Service Engine Soon" light to tell you that there is a problem and you need to diagnosed and repaired it. The list of possible codes number in the hundreds. The code itself doesn't tell exactly what component is defective - it only indicates where to look, or what engine parameter is out of normal range. You or a technician will have to perform further testing to pinpoint cause and the proper repair. If the light is flashing there is a severe failure of the emission-control system that is causing the engine to misfire to the point that the catalytic converter is damaged each time the Check Engine Light flashes. Even if you reset the light, if the underlying problem is not addressed it will come back on.