Tow/Haul Mode; Drive Systems; Four-Wheel Drive - GMC YUKON 2018 Owner's Manual

222 Driving and Operating

Tow/Haul Mode

The Tow/Haul Mode adjusts the
transmission shift pattern to reduce
shift cycling. This provides
increased performance, vehicle
control, and enhanced transmission
and engine cooling when driving
down steep hills or mountain
grades, towing, or hauling heavy
loads.
The selector button is on the end of
the shift lever. Turn the Tow/Haul
Mode on and off by pressing the
button. When the Tow/Haul Mode is
enabled, a light on the instrument
cluster will come on.
See Tow/Haul Mode Light 0 146 and
Hill and Mountain Roads 0 198.
Also see Tow/Haul Mode under
Towing Equipment 0 267.
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is
not in the Range Selection Mode.
See Tow/Haul Mode listed
previously and Manual Mode 0 218.
Tow/Haul Mode Grade Braking
assists in maintaining desired
vehicle speeds when driving on
downhill grades by using the engine
and transmission to slow the
vehicle.
To disable or enable Tow/Haul
Grade Braking within the current
ignition cycle, press and hold the
Tow/Haul button for five seconds.
When the button is released, the
requested mode change is made.
A DIC message is displayed.
See Towing Equipment 0 267.
For other forms of grade braking,
see Automatic Transmission 0 216
and Cruise Control 0 233.

Drive Systems

Four-Wheel Drive

If equipped, four-wheel drive
engages the front axle for extra
traction.
Caution
Do not drive on clean, dry
pavement in 4 and 4 (if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle s powertrain.
Driving on clean, dry pavement in 4
or 4 may:
Cause a vibration to be felt in
the steering system.
Cause tires to wear faster.
Make the transfer case harder to
shift, and cause it to run noisier.