Here's the proper procedure:
1. Diagnose the problem: The most important step is to find out *why* the check engine light is on. You can do this in a few ways:
* OBD-II Scanner: This is the best option. An OBD-II scanner (available relatively inexpensively at auto parts stores) will read the diagnostic trouble codes (DTCs) stored in your car's computer. These codes provide clues about what's wrong. You can then look up the codes online to understand their meaning.
* Auto Parts Store Check: Many auto parts stores will scan your car's computer for free. They'll give you the codes and may even offer advice on the potential problem.
2. Repair the problem: Once you know the DTCs and the likely cause, fix the problem. This might involve replacing a sensor, fixing a leak, or performing more extensive repairs.
3. Clear the code (after repair): *Only after you've successfully repaired the issue* should you clear the code. There are several ways to do this:
* OBD-II Scanner: Most OBD-II scanners have a function to clear trouble codes.
* Disconnect the Battery: A somewhat less reliable method is to disconnect the negative battery terminal for about 10-15 minutes. This will often clear the code, but it's not guaranteed and may not work for all problems.
Important Considerations:
* Don't just clear the code without fixing the problem: The check engine light will likely come back on if the underlying issue isn't resolved.
* Safety First: If you're not comfortable working on your car, take it to a qualified mechanic. Ignoring a check engine light can lead to serious and expensive problems.
In short, resetting the check engine light is a symptom treatment, not a cure. Focus on diagnosing and fixing the underlying mechanical or electrical issue first.
