GMC 2018 Acadia Denali Owner's Manual page 223

222 Driving and Operating
AWD (AWD Only) : AWD Mode
provides drive torque to all four
wheels. Select AWD to improve
traction and control on slippery road
surfaces, such as gravel, sand, wet
pavement, snow, and ice. When in
AWD Mode, the AWD Mode
indicator will be on. The AWD Mode
will stay selected until the mode is
changed.
AWD is active in AWD, Sport, Tow/
Haul, and Off-Road Modes.
Sport, Tow/Haul, and Off-Road
Modes are cancelled with each
ignition cycle and will return to Tour
(FWD) Mode.
When using a compact spare tire on
an AWD vehicle, the system
automatically detects the compact
spare and reduces AWD
performance to protect the system.
To restore full AWD operation and
prevent excessive wear on the
system, replace the compact spare
with a full-size tire as soon as
possible. See Compact Spare Tire
0 312.
Snow/Ice (FWD Only) : Snow/
Ice Mode improves vehicle
acceleration on snow and ice
covered roads.
Tow/Haul : This feature can
assist when towing or hauling a
heavy load. Use this mode to assist
in maintaining desired vehicle
speeds when driving on downhill
grades by using the engine and
transmission. For AWD vehicles,
choosing Tow/Haul Mode also
engages AWD mode. See Driving
Characteristics and Towing Tips
0 251.
Automatic Engine Grade Braking
Automatic Engine Grade Braking
assists when driving downhill.
It maintains vehicle speed by
automatically implementing a shift
pattern that uses the engine and the
transmission to slow the vehicle.
The system will automatically
command downshifts to reduce
vehicle speed. The normal shift
pattern will return once the vehicle
is on a low grade or when the
accelerator pedal is pressed.
While in the Electronic Range
Select (ERS) mode, grade braking
is deactivated, allowing the driver to
select a range and limiting the
highest gear available. Grade
braking is available for normal
driving and in Tow/Haul Mode.
See Automatic Transmission 0 212.
Off-Road (AWD Only) : Use
this mode for off-road recreational
driving. Choosing Off-Road Mode
also engages AWD Mode. For more
information on Off-Road Mode, see
Off-Road Driving 0 195.