Here's the proper approach:
1. Diagnose the Problem: The first and most crucial step is to find out *why* the light is on. You have several options:
* OBD-II Scanner: This is the best method. An OBD-II scanner (available relatively cheaply at auto parts stores) will read the diagnostic trouble codes (DTCs). These codes pinpoint the specific problem the computer has detected. You can then look up the code online to understand the issue.
* Auto Parts Store: Many auto parts stores offer free code reading services. They can tell you what the code means and potentially suggest solutions.
* Mechanic: If you're uncomfortable diagnosing the problem yourself, take it to a qualified mechanic.
2. Fix the Problem: Once you know the DTC, address the underlying issue. This might involve replacing a faulty sensor, fixing a leak, or performing other repairs.
3. Clear the Code (After Repair): *Only after you've fixed the problem* can you clear the code. There are several ways to do this:
* OBD-II Scanner: Most scanners have a function to clear the diagnostic trouble codes.
* Disconnect the Battery: This is a less reliable method. Disconnect the negative (-) battery terminal for about 15-20 minutes. This will often reset the computer, but it's not guaranteed to clear all codes. Reconnect the battery and start the vehicle. The light may take a few drive cycles to turn off if the problem is truly resolved.
Important Considerations:
* Driving with the light on: Ignoring the check engine light is not recommended. The problem could worsen, leading to more expensive repairs or even safety hazards.
* Intermittent Problems: Sometimes, a problem causing the check engine light might be intermittent. Even if you clear the code, it might return if the underlying issue isn't fixed.
In short, focus on fixing the problem, not just resetting the light. Using an OBD-II scanner is strongly recommended for proper diagnosis.
