Here's the proper approach:
1. Diagnose the Problem: The most crucial step. You need to find out *why* the light is on. There are several ways to do this:
* OBD-II Scanner: This is the best option. A relatively inexpensive OBD-II scanner (available at most auto parts stores) can read the diagnostic trouble codes (DTCs). These codes provide clues about the specific issue causing the light. The scanner will display the code(s) as a number (e.g., P0171). You can then look up the code online (many free resources exist) or in a repair manual to understand the problem.
* Auto Parts Store Check: Many auto parts stores offer free code reading services. They can tell you the code(s) and sometimes even offer advice on the potential problem.
* Professional Mechanic: If you're not comfortable diagnosing the problem yourself, take your Aztec to a qualified mechanic. They have the tools and expertise to diagnose and fix the issue accurately.
2. Repair the Problem: Once you know the DTC, you can address the root cause. This might involve:
* Replacing a faulty sensor: Many SES light triggers are caused by things like oxygen sensors, mass airflow sensors, etc.
* Fixing a loose gas cap: A surprisingly common cause! Make sure your gas cap is tightly sealed.
* More extensive repairs: In some cases, the problem might be more serious and require more significant repairs.
3. Clear the Code (After Repair): *Only* after you've repaired the problem, you can clear the code. Many OBD-II scanners have a function to clear codes. Some auto parts stores may also offer this service. After clearing the code, drive the vehicle for a while to ensure the problem is resolved. If the light comes back on, the repair wasn't successful, and you need to investigate further.
Important Note: Simply disconnecting the battery or using a code clearing tool *without* fixing the underlying problem will only temporarily turn off the light. The light will likely reappear soon, and the problem will remain unresolved. This is not a solution; it's a postponement of dealing with a potentially serious issue.
