GMC 2004 Yokon Denali Owner's Manual page 125

Tow/Haul Mode
Your vehicle is equipped with a Tow/Haul mode. The
button is located on the end of the column shift
lever. You can use this feature to assist when towing or
hauling a heavy load. See "Tow/Haul Mode" under
Towing a Trailer on page 4-55 for more information.
The Tow/Haul mode also interacts with the Autoride™
feature to enhance the ride when trailering or with a
loaded vehicle. See Autoride™ on page 4-54.
All-Wheel Drive
With this feature, engine power is sent to all four wheels
all the time.
This is like four-wheel drive, but there is no separate
lever or switch to engage or disengage the front axle. It
is fully automatic, and adjusts itself as needed for
road conditions.
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