The traction control can be turned off, but the AWD can't.
The Yukon Denali after 2003 uses an open center differential and ABS controlled AWD. The Sierra Denali 02-06 and Yukon Denali prior to 03 use a viscous coupler in the transfer case to achieve AWD. A 4x4 truck uses a locked center differential.
check out www.denalitrucks.com for tons of Denali/C3 info.