Your engine and transmission rely on a network of sensors to monitor things like the volume of air entering the engine, the crankshaft and cam position in real time, the oxygen content of the exhaust and many other factors. The engine computer uses this information to determine fuel metering and transmission shift points, and to keep emissions in check. An abnormal reading from a sensor can light up the Check Engine light on the dashboard, meaning that a trouble code has been stored in the computer. A tech can then access that code with a scan tool.
Beginning in the late 80s, engines started to rely more and more on sensors and electronics to manage fuel metering, emissions, transmission shift points and other performance factors. In the mid-90s, early systems for engine management were standardized into the OBD-II (On Board Diagnostic) system we're familiar with today.
When a sensor sends the engine computer a reading that's outside of normal parameters, the computer registers a trouble code and illuminates the Check Engine light on the dashboard. If your Check Engine light is on, it could mean something minor or something more significant. Stop by your local store and we can access your trouble codes free of charge. Just see one of our store associates