Late model vehicles are equipped with an on-board computer that manages all components, most notably the power train–from the fuel supply to exhaust gases–but also peripheral systems like the brakes, electric system, air conditioning, and even tire pressure, through a network of sensors linked to the computer.

When the main computer detects a problem, a light on the dashboard turns on. In some vehicles, a red light indicates issues that need immediate attention. In others, if the check engine light is flashing, the problem could also lead to serious damage. Your certified NAPA AUTOPRO technician will use a scan tool to get the diagnostic trouble code(s) of a defective part or component.