This is a feature that is enabled out of the box. The truck will run in the “NO POWER” mode until the engine coolant reaches the set temperature. The default temp is set at 172 degrees F. To change this temperature, or turn it off, go to the Main menu->Vehicle Setup->Set Defuel levels->Start up coolant temp. This can be lowered as low as 150 degrees F. It can also be turned off by pressing Defuel Off. To save changes just hit Go Back.