When I select the mode **** from 4x2 to 4x4 to 4x4 low the truck changes its 'tune' and behaves differently. It also changes when going from 'normal' to tow haul. What does the tuner do to each of these modes or is it all the same tune just different axle selection/range? Please forgive me as I posted this question in 2 areas within this forum.

 

Tow/haul affects the transmissions shifting. It raises the shift points and lowers the downshift throttle threshold so it kicks down to the next lower gear with less throttle input but I'm pretty sure that there is no change in any of these parameters when selecting a 4 wheel drive mode.

 

It actually holds gears longer before it kicks down, so it doesn't hunt for gears while towing.

 

Mine in 4x4 definitely alters the shift strategy closer to tow haul mode.