There are several kinds of malfunction lights on the dashboard of a Hyundai Elantra (and this is true on all Hyundai models). Some are comparatively minor, such as the one for "tire pressure is too low"-- and all it means is you should check the air in your tires at the nearest gas station. Or if the "check oil" light comes on, this means you are low on oil and any service station can put some oil in. Sometimes, especially when the car is new, a malfunction light called a "check engine light" may come on for no apparent reason. If the car is running fine, it could just means there's a problem with a sensor and the car's computer system needs to be re-set, which the dealer can take care of. But if the car suddenly is running rough, or it's barely running at all, the "check engine" light could indicate a more serious problem with the generator or the car's electrical system. You need to contact the dealer right away, and the service department can tell you what you should do. [Your Hyundai should have a manual that explains all the lights; if you don't have it, there are versions online.]