Page 307 of 478

Black plate (35,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-35
When going up steep hills,
you might have to step on the
accelerator pedal to maintain
the vehicle speed. When going
downhill, you might have to brake
or shift to a lower gear to keep the
vehicle speed down. When the
brakes are applied the cruise
control is disengaged.
Ending Cruise Control
There are three ways to end cruise
control:
.Step lightly on the brake pedal.
.Press the[button.
.To turn off the cruise control,
press
Ton the steering wheel.
Erasing Speed Memory
The cruise control set speed is
erased from memory by pressing
the
Tbutton or if the ignition is
turned off.
Object Detection
Systems
Ultrasonic Parking Assist
For vehicles with the Ultrasonic
Rear Parking Assist (URPA) system,
it operates at speeds less than
8 km/h (5 mph), and assists the
driver with parking and avoiding
objects while in R (Reverse).
The sensors on the rear bumper are
used to detect the distance to an
object up to 2.5 m (8 ft) behind the
vehicle, and at least 25.4 cm (10 in)
off the ground.
{WARNING
The Ultrasonic Rear Parking
Assist (URPA) system does not
replace driver vision. It cannot
detect:
.Objects that are below the
bumper, underneath the
vehicle, or too close or far
from the vehicle.
.Children, pedestrians,
bicyclists, or pets.
If you do not use proper care
before and while backing, vehicle
damage, injury, or death could
occur. Even with URPA, always
check behind the vehicle before
backing up. While backing, be
sure to look for objects and check
the vehicle's mirrors.
Page 320 of 478

Black plate (48,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-48 Driving and Operating
Pulling a Trailer
Here are some important points:
.There are many laws, including
speed limit restrictions that apply
to trailering. Check for legal
requirements.
.Consider using sway control.
SeeTowing Equipment on
page 9‑54.
.Do not tow a trailer at all during
the first 800 km (500 miles)
the new vehicle is driven.
The engine, axle or other
parts could be damaged.
.During the first 800 km
(500 miles) that a trailer is
towed, do not drive over 80 km/h
(50 mph) and do not make starts
at full throttle. This reduces wear
on the vehicle.
.The vehicle can tow in
D (Drive). Use a lower gear if
the transmission shifts too often.
See “Tow/Haul Mode” later in
this section.
.Obey speed limit restrictions
when towing a trailer.
.The vehicle is designed
primarily as a passenger and
load carrying vehicle. If a trailer
is towed, the vehicle will require
more frequent maintenance due
to the additional load.
Driving with a Trailer
Towing a trailer requires experience.
Get familiar with handling and
braking with the added trailer
weight. The vehicle is now longer
and not as responsive as the
vehicle is by itself.
Check all trailer hitch parts
and attachments, safety chains,
electrical connectors, lamps, tires
and mirror adjustments. If the trailer
has electric brakes, start the vehicle
and trailer moving and then apply
the trailer brake controller by hand
to be sure the brakes are working.
During the trip, check regularly to be
sure that the load is secure, and the
lamps and trailer brakes are working
properly.
Page 322 of 478

Black plate (50,1)GMC Acadia/Acadia Denali Owner Manual - 2011
9-50 Driving and Operating
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid situations
that require heavy braking and
sudden turns.
Passing
More passing distance is needed
when towing a trailer. Because the
rig is longer, it is necessary to go
farther beyond the passed vehicle
before returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand
to the left. To move the trailer to
the right, move your hand to the
right. Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Notice:Making very sharp turns
while trailering could cause the
trailer to come in contact with
the vehicle. The vehicle could
be damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer, make
wider turns than normal so the
trailer will not strike soft shoulders,
curbs, road signs, trees or other
objects. Use the turn signal well in
advance and avoid jerky or sudden
maneuvers.
Turn Signals When Towing a
Trailer
The turn signal indicators on the
instrument panel flash whenever
signaling a turn or lane change.
Properly hooked up, the trailer
lamps also flash, telling other
drivers the vehicle is turning,
changing lanes or stopping. When towing a trailer, the arrows on
the instrument panel flash for turns
even if the bulbs on the trailer are
burned out. Check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a
lower gear before starting down
a long or steep downgrade. If the
transmission is not shifted down,
the brakes might have to be used
so much that they would get hot and
no longer work well. See
“Automatic
Engine Grade Braking” withinTow/
Haul Mode on page 9‑28.
The vehicle can tow in D (Drive).
Use a lower gear if the transmission
shifts too often.
Page 323 of 478

Black plate (51,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Driving and Operating 9-51
When towing at high altitude on
steep uphill grades, engine coolant
will boil at a lower temperature than
at normal altitudes. If the engine is
turned off immediately after towing
at high altitude on steep uphill
grades, the vehicle may show
signs similar to engine overheating.
To avoid this, let the engine run
while parked, preferably on level
ground, with the transmission in
P (Park) for a few minutes before
turning the engine off. If the
overheat warning comes on, see
Engine Overheating on page 10‑19.
On a long uphill grade, shift down
and reduce the vehicle speed to
around 88 km/h (55 mph) to reduce
the possibility of the engine and the
transmission overheating.Parking on Hills
{WARNING
Parking the vehicle on a hill
with the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels. 3. When the wheel chocks are in
place, release the brake pedal
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
.Start the engine.
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Page 349 of 478

Black plate (21,1)GMC Acadia/Acadia Denali Owner Manual - 2011
Vehicle Care 10-21
If No Steam Is Coming from
the Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen
or heard, the problem may not be
too serious. Sometimes the engine
can get a little too hot when the
vehicle:
.Climbs a long hill on a hot day
.Stops after high-speed driving
.Idles for long periods in traffic
.Tows a trailerIf the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest
temperature and to the highest
fan speed. Open the windows as
necessary.
3. If in a traffic jam, shift to N (Neutral), otherwise, shift
to the highest gear while
driving —D (Drive) or L (Low).
If the temperature overheat gauge
is no longer in the overheat zone
or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive the vehicle slow
for about 10 minutes. Keep a safe
vehicle distance from the car in front
of you. If the warning does not come
back on, continue to drive normally.
If the warning continues, pull
over, stop, and park the vehicle
right away.
If there is no sign of steam, idle
the engine for three minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
“Overheated
Engine Protection Operating Mode”
next in this section.