Here are the most likely scenarios and how to address them:
* For a simple "Check Engine" light (CEL) that might be caused by a temporary issue (like a loose gas cap): The CEL will often turn off automatically after a few driving cycles if the problem that triggered it is resolved. Drive the car normally for a few days and see if it goes off.
* For a CEL caused by a more serious issue or to clear diagnostic trouble codes (DTCs) to start troubleshooting: You'll need to use a scan tool. This is a device that plugs into the car's OBD-I (On-Board Diagnostics) port (usually under the dashboard) to read and clear diagnostic trouble codes. Auto parts stores often offer free code reading services. Clearing the codes won't fix the problem, but it will give you a starting point for diagnosing it.
* For problems related to the car's adaptive learning: The computer adjusts its fuel mixture and other parameters based on driving habits and conditions. Sometimes, drastic changes (like replacing sensors or the battery) can cause the computer to need to relearn. This usually happens automatically over time with normal driving. Driving the car for 100-200 miles in varied driving conditions (city and highway) might help.
* For a completely unresponsive engine or other serious mechanical problem: A "computer reset" won't fix this. You have a far more serious issue that needs professional diagnosis and repair.
In short: There's no reset button. If you're experiencing a problem, accurately describe the symptom (e.g., "check engine light is on," "car won't start," "rough idle"). This will help determine the best course of action. Getting the codes read with a scanner is the most helpful first step for diagnosing engine problems.
