· the check-engine light is a signal that the onboard diagnostics system (or obd ii) has detected a malfunction in the vehicles emissions, ignition or fuel systems. · the check engine light alerts the driver to a possible problem with the vehicle’s engine, emissions, or another key system. What does a check engine light look like? Learn the common reasons for this light, how to diagnose and fix it, and when to seek professional help. You’ll also find practical steps to diagnose and fix the issue, along with answers to some of the most common questions drivers have. · in this guide, you’ll learn what the check engine light really means , the difference between a solid and flashing light, and the most common reasons it turns on. · discover common reasons why your check engine light is on and learn the easiest fixes to get your car back on the road safely. It stores an electronic code that indicates where the malfunction occurred. · what does your check engine light mean ? What causes a check engine light? How do i fix a check engine light? A check engine light is a warning indicator that alerts you to a potential problem with your engine or emissions system. The check engine light , also known as the malfunction indicator lamp, illuminates whenever one of your car’s computers or sensors is giving an.