An illuminated check engine light indicates a potential 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. For instance, a faulty oxygen sensor might trigger the light, affecting fuel efficiency, or a misfiring cylinder could lead to more substantial damage if ignored.
Understanding the implications of this warning is crucial for vehicle maintenance and driver safety. While driving with an illuminated check engine light might be possible in some cases, it’s essential to determine the underlying cause. Prompt diagnosis can prevent further damage, ensure optimal vehicle performance, and avoid potentially hazardous situations. Historically, vehicles lacked such sophisticated diagnostic systems, making it difficult for drivers to identify problems early. Modern onboard diagnostics provide a significant advantage in preventative maintenance and troubleshooting.