Often people believe an illuminated check engine light is just an electrical malfunction. In reality, a check engine light is one of the most effective and critical signs that your vehicle is functioning improperly. When illuminated, a check engine light alerts you to a variety of existing potential problems.
The check engine light is part of your vehicle's onboard diagnostics (OBD) system. The OBD system constantly monitors your vehicle's major operating systems most importantly, the engine and transmission. The primary purpose of monitoring these systems is to insure the vehicle is operating at top efficiency with the lowest possible emissions (http://1.usa.gov/1m8evet).
There are many reasons behind an illumined check engine light. The most common malfunctions that can cause the check engine light to illuminate include a loose gas cap, a faulty oxygen or mass airflow sensor, and worn down spark plugs and wires.
Because an illuminated check engine light can be potentially hazardous to your vehicle and the environment, it is important to visit an OBD certified technician within a couple days of the light going on. If the light is flashing, the condition is more urgent and should be checked immediately.
A technician will plug a computer into your vehicle, genreally located underneath the dashboard on the driver's side,
so the device can read the codes from your car's computer system. From the test, the check engine light codes tell your technician whether there is something wrong and points him or her in the right direction (http://bit.ly/1h7I6k5).
A check engine light isn’t necessarily a sign of costly repairs, but it is an important part of your OBD system to insure optimal vehicle functionality, personal safety and environmental safety.