GMC 2010 Yukon/Yukon XL Owner's Manual page 410

The automatic level control rear suspension is available
on light duty vehicles and comes as a part of the
®
Autoride suspension, if equipped.
This type of level control is fully automatic and will
provide a better leveled riding position as well as
better handling under a variety of passenger and
loading conditions. An air compressor connected to
the rear shocks will raise or lower the rear of the
vehicle to maintain proper vehicle height. The system
is activated when the ignition key is turned to ON/RUN
and will automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for up
to ten minutes after the ignition key has been turned off.
You may hear the air compressor operating when the
height is being adjusted.
If a weight distributing hitch is being used, it is
recommended to allow the shocks to inflate, thereby
leveling the vehicle prior to adjusting the hitch.
5-48
With this feature, improved vehicle ride and handling is
provided under a variety of passenger and loading
conditions.
The system is fully automatic and uses a computer
controller to continuously monitor vehicle speed, wheel
to body position, lift/dive and steering position of the
vehicle. The controller then sends signals to each shock
absorber to independently adjust the damping level to
provide the optimum vehicle ride.
Autoride also interacts with the tow/haul mode that,
when activated, will provide additional control of the
shock absorbers. This additional control results in better
ride and handling characteristics when the vehicle is
loaded or towing a trailer. See Tow/Haul Mode under
Towing a Trailer on page 5 49 for more information.