Look at page 12 of the manual.
After pressing [ENTER], the main display will come up. (Parameters and values may vary.) There are five boxes that display information about your vehicle. The black box in the top right corner tells which level is currently
programmed on your vehicle. The other four boxes can show up to 4 PIDs of your vehicle.
The Gryphon™ will default to RPM, MPH, TFT, and ECT. Optional parameters and display formats may be selected. Please see the SETUP section of this manual.
From this display, press [MENU] to select and use other features of the Gryphon™. The display backlight can also be controlled from this display using the [UP] and [DOWN] arrow keys.
Pressing [ENTER] while viewing these 4 PIDs will bring up a message asking you if you would like to reset the average economy. If you press [ENTER] again, the Gryphon™ will erase all fuel economy stored data which was in the Gryphon™ and restart the averaging function.