There are two main ways people attempt to reset the CEL:
* Using an OBD-II scanner: This is the proper way to approach the issue. An OBD-II scanner (available relatively cheaply online or at auto parts stores) can read the diagnostic trouble code (DTC) that's causing the light. This code tells you *why* the light is on. Once you know the code, you can research the problem and fix it. Many scanners also have a "clear codes" function that will turn off the light *after* the problem has been addressed.
* Disconnecting the battery: This is a temporary workaround that *may* clear the light, but it's unreliable and doesn't fix the underlying problem. The car's computer needs to complete a drive cycle (which involves driving for a certain amount of time and under specific conditions) to properly reset. The light will almost certainly return if the problem persists. This method is generally not recommended.
In short: Don't just reset the light. Find out *why* it's on first using an OBD-II scanner. Fix the problem, and then the light should go off automatically after a drive cycle or clearing the codes with the scanner. Ignoring the problem could lead to more serious damage to your vehicle.
