The check engine light (CEL) is a warning light that is displayed on the dashboard of a vehicle when there is an issue with the engine or the emissions system. The CEL is triggered by the vehicle's on-board diagnostic (OBD) system, which constantly monitors the vehicle's systems and components for issues. If the OBD system detects a problem, it will turn on the CEL and store a diagnostic trouble code (DTC) in the vehicle's computer.
If the CEL is illuminated, it is important to have the vehicle checked and repaired as soon as possible. Ignoring the CEL can lead to further damage to the vehicle and can potentially be dangerous while driving.
To diagnose and repair the issue that triggered the CEL, a mechanic will use a diagnostic tool to retrieve the DTC from the vehicle's computer. The DTC will give the mechanic an idea of what the issue is, and they can then perform further diagnostics and repair the problem.
If you have a CEL illuminated on your vehicle, it is recommended that you take it to a professional mechanic or an auto repair shop that specialized in check engine light services. They will be able to diagnose and repair the issue that triggered the CEL.