An illuminated check engine light signals a problem detected by the vehicle’s onboard diagnostic system. This problem could range from a minor issue like a loose gas cap to a more serious malfunction within the engine, transmission, or emissions system. A flashing check engine light usually indicates a severe issue requiring immediate attention.
Understanding the potential causes and implications of this warning is crucial for vehicle maintenance and driver safety. Ignoring the light could lead to further damage, costly repairs, reduced fuel efficiency, or even a breakdown. Historically, vehicles lacked such sophisticated diagnostic capabilities, making it more difficult to identify and address problems proactively. Modern onboard diagnostics represent a significant advancement in vehicle maintenance, enabling earlier detection and prevention of potentially catastrophic failures.