1. Ensure that the issue causing the check engine light is resolved. This may involve diagnosing and repairing any underlying problems with the vehicle's engine, emissions system, or other components.
2. Once the issue is resolved, turn off the ignition and disconnect the negative battery terminal. This will cut power to the vehicle and allow the computer system to reset.
3. Wait for a few minutes, then reconnect the negative battery terminal.
4. Turn on the ignition without starting the engine. This will allow the computer system to initialize and clear any stored fault codes.
5. Start the engine and let it run for several minutes. This will allow the computer to complete its self-diagnostic tests and confirm that the issue has been resolved.
6. If the check engine light stays off after these steps, the reset was successful. However, if the light turns on again, it indicates that there may still be an underlying problem that needs to be addressed.
Note that on some models or newer vehicles, the check engine light may not reset by simply disconnecting the battery. In these cases, you may need a diagnostic scan tool or professional help to reset the light and clear any fault codes from the computer system.
