Here's what you should do:
1. Get the Diagnostic Trouble Codes (DTCs): This is the crucial first step. You have several options:
* OBDII Scanner: The most reliable method. Buy a relatively inexpensive OBDII code reader from an auto parts store or online. Plug it into the OBDII port (usually under the dashboard) and it will read the codes. The codes will be numbers (e.g., P0171, P0420). Write these down.
* Auto Parts Store: Many auto parts stores will read the codes for free. They can then help you interpret the codes and suggest possible solutions.
* Mechanic: A mechanic will have the most sophisticated diagnostic equipment and expertise to identify the problem.
2. Interpret the DTCs (or have someone interpret them for you): Once you have the codes, you can look them up online (there are many free OBDII code lookup websites) or consult a repair manual. This will give you an idea of what the problem might be (e.g., oxygen sensor, mass airflow sensor, catalytic converter).
3. Fix the Problem: This is the most important step. Don't just reset the light; fix the underlying issue. Depending on your mechanical skills, you might be able to fix the problem yourself, or you'll need to take it to a mechanic.
4. Clear the DTCs (after fixing the problem): *Only* after you've addressed the issue that caused the SES light to illuminate, you can clear the codes. Many OBDII scanners have a "clear codes" function. Some advanced scanners may even allow you to perform specific tests. After clearing the codes, drive the vehicle for a few driving cycles (start, drive, and turn off the car a few times). The light should stay off if the problem is truly fixed. If the light returns, the problem wasn't fixed completely.
Important Considerations:
* DIY vs. Mechanic: Some repairs are simple (e.g., replacing a loose gas cap), while others are complex and require specialized tools and knowledge. Assess your skills honestly before attempting a repair.
* Safety: Work safely when performing any repairs. Disconnect the battery negative terminal before working on electrical systems.
* Cost: Factor in the cost of parts, tools, and potentially labor if you take it to a mechanic.
Simply resetting the light without fixing the underlying problem is masking the issue and could lead to further damage to your vehicle. Always address the root cause of the problem.
