2018 GMC ACADIA Owner's Manual

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
272 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 0232.
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-11349114) - 2018 - crc - 9/21/17
Driving and Operating 273
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 Overheating0295.
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 0369. 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
0 295.
Trailer Towing
Three important considerations
have to do with weight:
.
The weight of the trailer.
. The weight of the trailer tongue.
. The total weight on the vehicle's
tires.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
274 Driving and Operating
Weight of the Trailer
How heavy can a trailer safely be?
Speed, altitude, road grades,
outside temperature, the dimensions
of the front of the trailer, special
equipment, and the amount of
tongue weight the vehicle can carrymust be considered. See
“Weight of
the Trailer Tongue” later in this
section.
Maximum trailer weight is calculated
assuming only the driver is in the
tow vehicle and it has all the
required trailering equipment. The
weight of additional optional
equipment, passengers, and cargo in the tow vehicle must be
subtracted from the maximum trailer
weight.
Use the following chart to determine
how much the vehicle can weigh,
based upon the vehicle model and
options.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
Driving and Operating 275
VehicleMaximum Trailer Weight *GCWR
2.5L and 3.6L Engines 454 kg (1,000 lb)2 722 kg (6,000 lb)
3.6L Engine With V92 Trailer Towing Package 1 814 kg (4,000 lb)4 075 kg (8,984 lb)
*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment, and conversions. The GCWR for the vehicle should not be
exceeded.
Ask your dealer for trailering
information or advice.
Weight of the Trailer Tongue
The tongue load (1) of any trailer is
an important weight to measure
because it affects the total gross
weight of the vehicle. The Gross
Vehicle Weight (GVW) includes the
curb weight of the vehicle, any
cargo carried in it, and the people
who will be riding in the vehicle.
If there are a lot of options,
equipment, passengers or cargo in
the vehicle, it will reduce the tongue
weight the vehicle can carry, which
will also reduce the trailer weight the
vehicle can tow. If towing a trailer,
the tongue load must be added to the GVW because the vehicle will
be carrying that weight, too. See
Vehicle Load Limits
0217.
In general, trailer tongue weight (1)
should be 10-15 percent of the
loaded trailer weight (2). Some specific trailer types (especially boat
trailers) fall outside of this range. In
this case, the recommended tongue
weight in the trailer owner
’s manual
should be observed. In all cases,
the maximum loads for the vehicle
series and hitch type should not be
exceeded.
After loading the trailer, weigh the
trailer and then the tongue,
separately, to see if the weights are
proper. If they are not, adjustments
might be made by moving some
items around in the trailer.
Trailering may be limited by the
vehicle's ability to carry tongue
weight. Tongue weight cannot cause
the vehicle to exceed the GVWR
(Gross Vehicle Weight Rating) or

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
276 Driving and Operating
the RGAWR (Rear Gross Axle
Weight Rating). The effect of
additional weight may reduce the
trailering capacity more than the
total of the additional weight.
It is important that the vehicle does
not exceed any of its ratings—
GCWR, GVWR, RGAWR, Maximum
Trailer Rating or Tongue Weight.
The only way to be sure it is not
exceeding any of these ratings is to
weigh the vehicle and trailer.
Total Weight on the Vehicle's
Tires
Inflate the vehicle's tires to the
upper limit for cold tires. These
numbers can be found on the
Certification label or see Vehicle
Load Limits 0217 for more
information. Do not go over the
GVW limit for the vehicle, or the
GAWR, including the weight of the
trailer tongue. If using a weight
distributing hitch, do not go over the
rear axle limit before applying the
weight distribution spring bars.
Towing Equipment
Hitches
It is important to have the correct
hitch equipment. Crosswinds, large
trucks going by, and rough roads
are a few reasons why the right
hitch is needed.
. The rear bumper on the vehicle
is not intended for hitches. Do
not attach rental hitches or other
bumper-type hitches to it. Use
only a frame-mounted hitch that
does not attach to the bumper.
. Will any holes be made in the
body of the vehicle when the
trailer hitch is installed? If so,
then be sure to seal the holes
when the hitch is removed. If the
holes are not sealed, dirt, water,
and deadly carbon monoxide
(CO) from the exhaust may get
into the vehicle. See Engine
Exhaust 0228. Weight-Distributing Hitches and
Weight Carrying Hitches
1. Front of Vehicle
2. Body-to-Ground Distance
When using a weight-distributing
hitch, the hitch must be adjusted so
that the distance (2) remains the
same both before and after coupling
the trailer to the tow vehicle.
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue of
the trailer to help prevent the tongue
from contacting the road if it

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
Driving and Operating 277
becomes separated from the hitch.
Always leave just enough slack so
the rig can turn. Never allow safety
chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 450 kg (1,000 lb) must be
equipped with its own brake system,
with brakes working on all axles.
Trailer braking equipment
conforming to Canadian Standards
Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended.
State and local regulations may also
require the trailer to have its own
braking system if loaded above a
certain threshold. These
requirements vary from state to
state.
Be sure to read and follow the
instructions for the trailer brakes so
they are installed, adjusted, and
maintained properly.Because the vehicle has antilock
brakes, do not tap into the vehicle's
hydraulic brake system. If you do,
both brake systems will not work
well, or at all.Trailer Wiring Harness
Basic Trailer Wiring
The trailer wiring harness, with a
seven-pin connector, is located at
the rear of the vehicle and is tied to
the vehicle's frame. The harness
connector can be plugged into a
seven-pin universal heavy-duty
trailer connector available through
your dealer.
Use only a round, seven-wire
connector with flat blade terminals
meeting SAE J2863 specifications
for proper electrical connectivity.
The seven-wire harness contains
the following trailer circuits:
.
Yellow/Gray: Stop/Turn
Signal Left
. Green/Violet: Stop/Turn Signal
Right
. Gray/Brown: Parking Lamps .
White/Green: Back-up Lamps
. Red/Green: Back-up Lamps
. Black: Ground
. Blue: Electric Brake*
*The fuse for this circuit is installed
in the underhood electrical center,
but the wires are not connected.
They should be connected by your
dealer or a qualified service center.
If the back-up lamp circuit is not
functional, contact your dealer.
If a remote (non-vehicle) battery is
being charged, turn the Tow/Haul
Mode knob on the center console.
This will boost the vehicle system
voltage and properly charge the
battery. If the trailer is too light for
Tow/Haul Mode, turn on the
headlamps (non-HID only) as a
second way to boost the vehicle
system and charge the battery.
Electric Trailer Brake Control
Wiring Provisions
These wiring provisions for an
electric trailer brake controller are
included with the vehicle as part of

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
278 Driving and Operating
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) 0136.
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 089 and Adding Equipment
to the Airbag-Equipped Vehicle
0 90.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349114) - 2018 - crc - 9/21/17
Vehicle Care 279
Vehicle Care
General Information
General Information . . . . . . . . . . 280
California Proposition65 Warning . . . . . . . . . . . . . . . . . 280
California Perchlorate Materials Requirements . . . . . 281
Accessories and Modifications . . . . . . . . . . . . . . . . 281
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 281
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 282
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 283
Engine Oil . . . . . . . . . . . . . . . . . . . . 286
Engine Oil Life System . . . . . . . 288
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 289
Engine Air Cleaner/Filter . . . . . . 290
Cooling System . . . . . . . . . . . . . . 291
Engine Overheating . . . . . . . . . . 295
Washer Fluid . . . . . . . . . . . . . . . . . 296
Brakes . . . . . . . . . . . . . . . . . . . . . . . 297
Brake Fluid . . . . . . . . . . . . . . . . . . . 298
Battery - North America . . . . . . 299
All-Wheel Drive . . . . . . . . . . . . . . . 300 Starter Switch Check . . . . . . . . . 300
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 300
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 300
Wiper Blade Replacement . . . . 301
Windshield Replacement . . . . . 302
Gas Strut(s) . . . . . . . . . . . . . . . . . . 302
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 303
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 304
Halogen Bulbs . . . . . . . . . . . . . . . . 304
LED Lighting . . . . . . . . . . . . . . . . . 304
License Plate Lamp . . . . . . . . . . 304
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . . . 305
Electrical System Overload . . . 305
Fuses and Circuit Breakers . . . 306
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 306
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 309
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 311
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 314
All-Season Tires . . . . . . . . . . . . . . 315
Winter Tires . . . . . . . . . . . . . . . . . . 315
Summer Tires . . . . . . . . . . . . . . . . 315
Tire Sidewall Labeling . . . . . . . . 316
Tire Designations . . . . . . . . . . . . . 318
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 319
Tire Pressure . . . . . . . . . . . . . . . . . 321
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 323
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 323
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 324
Tire Inspection . . . . . . . . . . . . . . . . 328
Tire Rotation . . . . . . . . . . . . . . . . . 328
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 329
Buying New Tires . . . . . . . . . . . . . 330
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 332
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 332
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 333
Wheel Replacement . . . . . . . . . . 334
Tire Chains . . . . . . . . . . . . . . . . . . . 334
If a Tire Goes Flat . . . . . . . . . . . . 335