Drive Systems; All-Wheel Drive - GMC Acadia Owner's Manual

Push the button to activate the
system. Push it again to deactivate
the system. You can use this feature
to assist when towing or hauling a
heavy load.
When Tow/Haul is activated, the
Tow/Haul symbol will come on in the
instrument cluster. See Tow/Haul
Mode under Driving Characteristics
and Towing Tips on page 9-46.
Automatic Engine Grade
Braking
Automatic Engine Grade Braking
assists when driving on a downhill
grade. It maintains vehicle speed by
automatically implementing a shift
schedule that uses the engine and
the transmission to slow the vehicle.
The system will automatically
command downshifts to reduce
vehicle speed, until the brake pedal
is no longer being 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 on
page 9-22.
Driving and Operating

Drive Systems

All-Wheel Drive

Vehicles with this feature transfer
engine power, as required, to all
four wheels. It is fully automatic, and
adjusts itself as needed for road
conditions.
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
on page 10-67.
9-25