Here's the correct approach:
1. Diagnose the Problem: The first and most crucial step is to find out *why* the check engine light is on. You have several options:
* OBD-II Scanner: This is the best approach. An OBD-II scanner (available relatively cheaply at auto parts stores) will read the diagnostic trouble codes (DTCs). These codes give you a specific indication of what the problem is. Many scanners also provide descriptions of the codes.
* Auto Parts Store: Most auto parts stores will scan your vehicle's codes for free. They can often tell you what the code means.
* Mechanic: A mechanic can diagnose the problem and recommend repairs. This is the most expensive option, but it ensures the problem is correctly identified and fixed.
2. Repair the Problem: Once you know the DTC(s), you can address the underlying issue. This could be anything from a loose gas cap to a more serious problem like a failing sensor or catalytic converter. Do *not* just clear the code without fixing the problem.
3. Clear the Code (After Repair): *Only after you've repaired the problem* should you clear the code. Many OBD-II scanners have a "clear codes" function. Some vehicles will automatically clear the code after a certain number of successful driving cycles (meaning the problem hasn't reoccurred). If your scanner doesn't have a clear codes function, some auto parts stores might perform this service.
Important Considerations:
* Don't just disconnect the battery: While disconnecting the battery for a period of time *might* temporarily clear the light, it won't solve the underlying issue. The check engine light will likely return.
* Ignoring the light is dangerous: Driving with a check engine light on can lead to further damage to your vehicle, reduced fuel economy, and potentially unsafe driving conditions.
In short: Find the problem, fix the problem, then clear the code. Trying to reset the light without fixing the root cause is a waste of time and potentially harmful.
