2009 Chevrolet Suburban 2500 Owner's Manual - Page 377

Level Control { CAUTION: Shifting a four-wheel-drive vehicle's transfer case into N (Neutral) can cause the vehicle to roll even if the transmission is in P (Park). The driver or others could be injured. Make sure the parking brake is firmly set before the transfer case is shifted to N (Neutral). 7. Shift the transfer case to N (Neutral). See "Shifting into N (Neutral)" under Four-Wheel Drive on page 2-40. 8. Turn the ignition to LOCK/OFF. After towing, see "Shifting Out of N (Neutral)" under Four-Wheel Drive on page 2-40. Automatic Level Control 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. 4-49