The Check Engine light — sometimes called the Service Engine Soon light or Malfunction Indicator Lamp (MIL) — is the computer’s way of communicating with you. When the light comes on, it’s telling you it noticed a problem with the way the car’s operating.
That problem may be something as simple as a loose gas cap; even driving down a rough road can turn the Check Engine light on in some cases.
Your best bet when you see the Check Engine light come on is to take your car to your local Cottman center. They’ll perform a computer system scan — absolutely free! — and see whether you’re looking at something really simple, or need a more in-depth diagnosis.