What is at check on 2009 Nissan Altima means?

The "Check Engine" light on a 2009 Nissan Altima indicates that the vehicle's onboard diagnostic system has detected an issue with the engine or emissions system. This could range from a loose gas cap to more serious problems like engine misfires or issues with the catalytic converter. It's important to have the vehicle scanned for error codes at a mechanic or auto parts store to identify the specific problem. Ignoring the light could lead to decreased performance or more significant damage over time.