The dashboard in your car contains a series of warning lights and gauges to inform you when there may be a malfunction. Some, like the temperature and gas gauges are easy to read and interpret. One of the most misunderstood is the "check engine" light. When it comes on it can mean something simple like a loose gas cap or something seriously wrong with the engine.
The Check Engine light is triggered by a computer in your car. The computer is connected to a series of electronic sensors that monitor things like engine speed, ignition timing and fuel mixture. Emission levels, and some scheduled maintenance services are also monitored by the onboard computer in your car.
If the computer gets a signal from any of the sensors in your car that it can't correct automatically it will turn on the Check Engine light on your dashboard. At the same time the computer stores a code that indicates why the light came on. The code makes it easy to diagnose the problem and helps reduce the cost of repairs. The code can be read with a special electronic tool or a diagnostic machine.
While the light is often just a reminder that a scheduled service is due, it often indicates something more serious. The light may blink or be steady. Either way it indicates something that needs attention. In newer cars, a blinking light, generally means something more serious wrong. For example something causing a misfire results in bad mileage and can cause expensive damage to parts like the catalytic converter in your car. A steady light probably indicates something less serious, but you should still call Roy's Pro Auto to have it diagnosed ASAP.
The computer in your car may actually make corrections to compensate for whatever triggered the light. Even though the car may be running OK you should still have it diagnosed to see what caused the light to come on in the first place and have it fixed before serious damage can occur.