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]