Is there a fuel reset button on the 2003 GMC Yukon?

No, there is no fuel reset button on a 2003 GMC Yukon (or any other vehicle, for that matter) in the way that you might be thinking. There's no button to magically reset your fuel economy or mileage.

The fuel economy displayed on the instrument cluster is calculated based on recent driving data. It will update over time as you drive. If you want a more accurate reading, you can reset the *trip odometer* (usually a small button on your instrument cluster), which will reset the fuel economy calculation for that specific trip. This doesn't affect the actual fuel used, just the running calculation.