Here's what you should do:
1. Get the diagnostic trouble code (DTC): You need to find out *why* the light is on. You can do this in a few ways:
* OBD-II Scanner: Purchase a relatively inexpensive OBD-II scanner from an auto parts store or online. Plug it into the OBD-II port (usually under the dashboard) and it will read the DTC code(s). This is the most reliable method.
* Auto Parts Store: Many auto parts stores will read the code for free. Just be aware that they may try to sell you parts or services to fix the problem.
2. Interpret the DTC: Once you have the code(s), look them up online. Many websites (like various car forums or repair manuals) provide a database of DTCs and their meanings. This will give you an idea of what system is malfunctioning.
3. Address the problem: This is the crucial step. The solution depends entirely on the DTC. It could be something simple like a loose gas cap, a faulty sensor, or a more serious mechanical issue.
* Simple Fixes: If the problem is minor (like a loose gas cap), tightening it might reset the light automatically after a few driving cycles.
* More Complex Repairs: If it's a more serious issue, you might need to replace a faulty sensor, repair a component, or take it to a mechanic.
4. Clear the code (after repair): Once you've fixed the problem, you can clear the DTC using your OBD-II scanner. The SES light should stay off if the repair was successful. If the light returns, the problem wasn't fully resolved.
Warning: Simply disconnecting the battery or using a code clearing tool *without* fixing the underlying problem is a temporary fix at best. The light will almost certainly come back on, and the problem could worsen. It's essential to diagnose and repair the root cause of the issue.
