So you come out to start your car one morning and the Check Engine light on the dashboard comes on…and doesn’t go back off again. You can’t really notice any difference in the way the car runs and drives, but it’s on anyway.
What does it mean?
Since the late 80s, most engine functions have been controlled by a central drivetrain computer. This includes emissions controls, fuel metering and delivery, ignition timing, shift points and many other elements of drivability and performance. The drivetrain computer relies on information from a chain of sensors that monitor exhaust composition, camshaft position, throttle position and many other factors.
The voltage readings from any of these sensors are supposed to fall within a certain range. When ...[more]
An illuminated check engine light is a signal from the vehicle's engine computer that something is wrong. Many people worry that it means a costly repair is needed, but that's not always the case. Here are some of the common reasons why a check engine light turns on.
Loose or Broken Gas Cap
Probably the most common reason for an illuminated check engine light is a gas cap that hasn't been screwed on tightly. When it's loose or cracked, fuel vapors leak out and can throw the whole fuel system off. This also ...[more]