Fuel Cooler (if equipped)
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
The fuel cooler is located under the vehicle and the returning fuel runs though it in order to cool the fuel before returning to the vehicle's fuel tank.