GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
236 Driving and Operating
While in L (Low), the transmission
will prevent shifting to a lower gear
range if the engine speed is too
high. You have a brief period of time
to slow the vehicle. If vehicle speed
is not reduced within the time
allowed, the lower gear range shift
will not be completed. You must
further slow the vehicle, then press
−(Minus) to the desired lower gear
range.
Automatic Engine Grade Braking is
not available when the ERS is
active. It is available in D (Drive) for
both normal driving and Tow/Haul
Mode. While using the ERS, cruise
control and the Tow/Haul Mode can
be used. See “Tow/Haul Mode”
following.
Tow/Haul Mode
See Driver Mode Control 0242.
Drive Systems
All-Wheel Drive
Vehicles with this feature can
operate in AWD Mode, see Driver
Mode Control 0242.
Brakes
Antilock Brake
System (ABS)
This vehicle has an Antilock Brake
System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the vehicle begins to drive
away, ABS checks itself.
A momentary motor or clicking noise
may be heard while this test is going
on, and it may even be noticed that
the brake pedal moves a little. This
is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning
Light 0135.
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
Driving and Operating 237
If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses the wheels are
slowing down. If one of the wheels
is about to stop rolling, the computer
will separately work the brakes at
each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
you steer around the obstacle while
braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You may hear the ABS
pump or motor operating and feel
the brake pedal pulsate. This is
normal.
Braking in Emergencies
ABS allows you to steer and brake
at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Electric Parking Brake
The Electric Parking Brake (EPB)
switch is on the instrument panel, to
the left of the steering wheel. The
EPB can always be activated, even
if the ignition is off. To prevent
draining the battery, avoid repeated
cycles of the EPB when the engine
is not running.
The system has a red parking brake
status light and an amber parking
brake warning light. SeeElectric
Parking Brake Light 0135 and
Service Electric Parking Brake Light
0 135. There are also parking
brake-related Driver Information
Center (DIC) messages. See Brake
System Messages 0148. In case of
insufficient electrical power, the EPB
cannot be applied or released.
Before leaving the vehicle, check
the red parking brake status light to
ensure that the parking brake is
applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the switch momentarily.
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
240 Driving and Operating
Ride Control Systems
Traction Control/
Electronic Stability
Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak®, an
electronic stability control system.
These systems help limit wheel spin
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any
of the drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to
the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak selectively applies
braking pressure to any one of the vehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path.
If cruise control is being used and
TCS or StabiliTrak begins to limit
wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road
conditions allow. TCS and
StabiliTrak will automatically turn on
when cruise control is set.
Both systems come on
automatically when the vehicle is
started and begins to move. The
systems may be heard or felt while
they are operating or while
performing diagnostic checks. This
is normal and does not mean there
is a problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary
to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow.
See
If the Vehicle Is Stuck 0220
and “Turning the Systems Off and
On” later in this section.
The indicator light for both systems
is in the instrument cluster. This
light will:
.
Flash when TCS is limiting
wheel spin.
. Flash when StabiliTrak is
activated.
. Turn on and stay on when either
system is not working.
If either system fails to turn on or to
activate, a message displays in the
Driver Information Center (DIC),
and
dcomes on and stays on to
indicate that the system is inactive
and is not assisting the driver in
maintaining control. The vehicle is
safe to drive, but driving should be
adjusted accordingly.
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
270 Driving and Operating
may not pass a smog-check test.
SeeMalfunction Indicator Lamp
(Check Engine Light) 0132. If this
occurs, return to your authorized
dealer for diagnosis. If it is
determined that the condition is
caused by the type of fuel used,
repairs may not be covered by the
vehicle warranty.
Fuels in Foreign
Countries
The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock
index (AKI). For fuel not to use in a
foreign country, see “Prohibited
Fuels” inFuel 0269.
Fuel Additives
To keep fuel systems clean, TOP
TIER Detergent Gasoline is
recommended. See Fuel0269.
If TOP TIER Detergent Gasoline is
not available, one bottle of GM Fuel
System Treatment Cleaner added to
the fuel tank at every engine oil
change, can help. GM Fuel System
Treatment Cleaner is the only gasoline additive recommended by
General Motors. It is available at
your dealer.
Filling the Tank
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
. To help avoid injuries to you
and others, read and follow
all the instructions on the
fuel pump island.
. Turn off the engine when
refueling.
. Keep sparks, flames, and
smoking materials away
from fuel.
. Do not leave the fuel pump
unattended.
. Do not use a cell phone
while refueling.
. Do not reenter the vehicle
while pumping fuel.
(Continued)
Warning (Continued)
.Keep children away from
the fuel pump and never let
children pump fuel.
. Fuel can spray out if the
refueling nozzle is inserted
too quickly. This spray can
happen if the tank is nearly
full, and is more likely in hot
weather. Insert the refueling
nozzle slowly and wait for
any hiss noise to stop prior
to beginning to flow fuel.
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
Driving and Operating 273
.Do not tow a trailer during the
first 800 km (500 mi), to prevent
damage to the engine, axle or
other parts.
. Then, during the first 800 km
(500 mi) trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
. The vehicle can tow in D (Drive)
but Manual Mode is
recommended. See Manual
Mode 0235. Use a lower gear if
the transmission shifts too often.
. Turn off Parking Assist and Rear
Cross Traffic Alert (RCTA) when
towing.
. Turn off Lane Keep Assist (LKA)
when towing.
. Do not use Adaptive Cruise
Control (ACC) when towing a
trailer.{Warning
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
When towing a trailer:
. Do not drive with the
liftgate, trunk/hatch,
or rear-most window open.
. Fully open the air outlets on
or under the instrument
panel.
. Also adjust the climate
control system to a setting
that brings in only outside
air. See “Climate Control
Systems” in the Index.
For information about carbon
monoxide, see Engine
Exhaust 0232.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Towing with a Stability Control
System
When towing, the sound of the
stability control system might be
heard. The system is reacting to the
vehicle movement caused by the
trailer, which mainly occurs during
cornering. This is normal when
towing heavier trailers.
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
274 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 your 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 TurnsCaution
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 cluster 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 cluster 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.
The vehicle can tow in D (Drive).
Use a lower gear if the transmission
shifts too often.
The Tow/Haul Mode may be used if
the transmission shifts too often.
See
Tow/Haul Mode 0236.
When towing at high altitude on
steep uphill grades, engine coolant
boils 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 could show
signs similar to engine overheating.
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
Driving and Operating 275
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 Overheating0297.
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.
Maintenance When Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule 0368.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system and
brake system. Inspect these before
and during the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine
Overheating 0297.
GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9803770) - 2017 - crc - 7/12/16
280 Driving and Operating
Electric Trailer Brake Control
Wiring Provisions
These wiring provisions for an
electric trailer brake controller are
included with the vehicle as part of
the trailer wiring package. The
instrument panel contains blunt cut
wires above the parking brake
assembly for the electric trailer
brake controller. The harness
contains the following wires:
.Blue: “To Trailer”
. Red/Black or Red/Blue:
Battery Feed
. White/Blue: Brake Apply Signal
. Black: Ground
The electric trailer brake controller
should be installed by your dealer or
a qualified service center.Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. See Malfunction Indicator
Lamp (Check Engine Light)
0 132. A device connected to the
DLC —such as an aftermarket
fleet or driver-behavior tracking
device —may interfere with
vehicle systems. This could affect
vehicle operation and cause a
crash. Such devices may also
access information stored in the
vehicle’s systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 085 and Adding Equipment
to the Airbag-Equipped
Vehicle 086.