1. Locate the diagnostic connector on the vehicle. It's usually located under the dashboard on the driver's side.
2. Connect a scan tool or code reader to the diagnostic connector.
3. Turn on the ignition key to the on position (engine off).
4. Use the scan tool or code reader to retrieve the trouble codes stored in the vehicle's computer.
5. Once you've retrieved the codes, clear them using the scan tool or code reader.
6. Turn off the ignition key and disconnect the scan tool or code reader.
7. Start the engine and check if the check engine light has turned off.
If the check engine light is still on after following these steps, you may need to have the vehicle diagnosed by a mechanic to determine the cause of the issue.