How to turn off check engine light on 2002 Passat?

To turn off the check engine light on a 2002 Volkswagen Passat, you can start by using an OBD-II scanner to read the diagnostic trouble codes (DTCs) and address any underlying issues. Once the issues are resolved, the light can be reset either through the scanner or by disconnecting the car's battery for about 15 minutes. After reconnecting the battery, the light should be off if the problem has been fixed. If the light remains on, further diagnosis may be needed.