Here's the proper approach:
1. Diagnose the Problem: The check engine light itself doesn't tell you *what* is wrong. You need to get a diagnostic trouble code (DTC). You can do this a few ways:
* OBDII Scanner: Buy a relatively inexpensive OBDII code reader at an auto parts store. Plug it into the OBDII port (usually under the dashboard) and it will retrieve the code(s). The code(s) will give you a clue about the problem.
* Auto Parts Store: Many auto parts stores will read the codes for free. They might even offer advice based on the code.
* Mechanic: A mechanic will have the best tools and expertise to diagnose the problem accurately.
2. Fix the Problem: Once you know the DTC, you can research the likely cause (online forums, repair manuals, etc.) or take it to a mechanic. The problem could range from a loose gas cap to a serious engine issue. Fixing the underlying problem is crucial.
3. Clear the Code (After Repair): *Only after* you've fixed the problem, you can clear the code. Many OBDII scanners have a "clear codes" function. Some auto parts stores will do this for free as well. After clearing the code, drive the vehicle for a short while. If the problem is truly fixed, the light should stay off. If it comes back on, the problem wasn't solved, and you need to repeat the process.
WARNING: Simply disconnecting the battery or using a code clearing tool without fixing the underlying issue will only temporarily turn off the light. The problem will likely remain and could worsen, potentially causing significant damage to your vehicle.
