Tune up Discussion of the basics
Do not delay getting your car in to your favorite repair shop if the check engine light suddenly goes on. A check engine light can illuminate for reasons as minor as a loose gas cap or as serious as a malfunctioning engine. A check engine light usually indicates that the onboard diagnostics check has discovered an improperly working component that must be taken care of immediately to avoid permanent damage to your system. Ignore it at your peril. In late model cars, the check engine light will behave differently depending on the seriousness of the problem.