Seems to me it has something to do with shifting from park to drive, once for level one, twice for level 2 and so on. The engine will surge when you change the tunes, once for level one and so on.
Thats what I thought to and we were correct. I finally found it on Edge's site.
NOTE: If you have the Attitude installed, the following procedure does
NOT apply. Power levels are changed using the Attitude.
1. Set the Parking Brake
2. Turn key on without starting the engine (engine must not be running).
3. Select the desired transmission mode to set the power level for (Normal or
Tow/Haul).
4. Place gear selector in the gear corresponding to desired power level (D=4,
3=3, 2=2, 1=1, R=stock).
5. Press accelerator to the floor two times, completely releasing the pedal
each time.
6. Return gear selector to Park and start the engine.
7. Press the Tow/Haul button twice. This causes the Juice module to
“remember” the level setting for the mode.
Power Level Confirmation
To confirm the power level that is selected:
1. Place gear selector in Park with your foot off of the accelerator while
engine is idling
2. Set the Parking Brake
3. Select Normal or Tow/Haul mode, depending upon the transmission mode
power setting you wish to confirm
4. Place gear selector to reverse, neutral, reverse, then back to park. P-R-NR-
P
5. The engine will rev to coincide with the power level selected, revving 4
times for level 4, 3 times for level 3, and so on