brake GMC ACADIA 2021 Repair Manual

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 259
Viewing Systems
If equipped, the viewing systems on the
vehicle can improve visibility while hitching,
backing, and driving with a trailer. See
Driver Assistance Systems0239 and
Assistance Systems for Parking or Backing
0 241.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible.
When parking your vehicle and your trailer
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, gradually release the brake pedal to
allow the chocks to absorb the load of
the trailer. 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:
.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
used to tow trailers. See Maintenance
Schedule 0346. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically that all nuts and bolts on
the trailer hitch are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily
overheat during severe operating conditions.
See Engine Overheating 0285.
Trailer Towing
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
tow a trailer correctly, follow the
directions in this section and see your
dealer for important information about
towing a trailer with the vehicle.
Trailer Weight
{Warning
Never exceed the towing capacity for
your vehicle.
Safe trailering requires monitoring the
weight, speed, altitude, road grades, outside
temperature, dimensions of the front of the
trailer, and how frequently the vehicle is
used to tow a trailer.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
260 Driving and Operating
Trailer Weight Ratings
When towing a trailer, the weight of the
loaded vehicle and trailer must be within
the weight ratings for the vehicle.
.GCWR: Gross Combined Weight Rating
.GVWR: Gross Vehicle Weight Rating
.Maximum Trailer Weight Rating
.Maximum Trailer Tongue Weight
The only way to be sure the weight is not
exceeding any of these ratings is to weigh
the tow vehicle and trailer combination,
fully loaded for the trip, getting individual
weights for each of these items.
{Warning
You and others could be seriously injured
or killed if the trailer is too heavy or the
trailer brakes are inadequate for the load.
The vehicle may be damaged, and the
repairs would not be covered by the
vehicle warranty.
Only tow a trailer if all the steps in this
section have been followed. Ask your
dealer for advice and information about
towing a trailer.
Gross Combined Weight Rating (GCWR)
GCWR is the total allowable weight of the
completely loaded vehicle and trailer
including any fuel, passengers, cargo,
equipment, and accessories. Do not exceed
the GCWR for your vehicle. The GCWR for
the vehicle is on the Tow Rating Chart
following.
Gross Vehicle Weight Rating (GVWR)
For information about the vehicle's
maximum load capacity, see Vehicle Load
Limits 0209. When calculating the GVWR
with a trailer attached, the trailer tongue
weight must be included as part of the
weight the vehicle is carrying.
Maximum Trailer Weight Rating
The maximum trailer weight rating is
calculated assuming the tow vehicle has a
driver, a front seat passenger, and all
required trailering equipment. Weight of
additional optional equipment, passengers,
and cargo in the tow vehicle must be
subtracted from the trailer weight rating.
Use the tow rating chart to determine how
much the trailer can weigh, based on the
vehicle model, powertrain and trailering
options.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 263
2. Push the bottom of the cover forwarduntil the lower tabs line up with the
lower slots (1).
3. Snap the hitch cover into place by pushing the upper corners forward.
4. Reinstall the two fasteners on the lower tabs (2).
Consider using mechanical sway controls
with any trailer. Ask a trailering professional
about sway controls or refer to the trailer
manufacturer's recommendations and
instructions.
Weight-Distributing Hitch Adjustment
1. Front of Vehicle
2. Body to Ground Distance
When using a weight-distributing hitch,
measure the front fender height distance (2)
before connecting the trailer. Adjust the
spring bars until the front fender height
distance (2) is the same height before the
trailer was connected. Do not reduce the
front fender height below the initial
distance (2).
Tires
.Do not tow a trailer while using a
compact spare tire on the vehicle.
.Tires must be properly inflated to support
loads while towing a trailer. See Tires
0 300 for instructions on proper tire
inflation.
Safety Chains
Always attach chains between the vehicle
and the trailer, and attach the chains to the
holes on the trailer hitch platform.
Instructions about safety chains may be
provided by the hitch manufacturer or by
the trailer manufacturer.
Cross the safety chains under the tongue of
the trailer to help prevent the tongue from
contacting the road if it becomes separated
from the hitch. Always leave just enough
slack so the combination can turn. Never
allow safety chains to drag on the ground.
Trailer Brakes
Loaded trailers over 450 kg (1,000 lb) must
be equipped with brake systems and with
brakes for each axle. Trailer braking
equipment conforming to Canadian
Standards Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended.
State or local regulations may require
trailers to have their own braking system if
the loaded weight of the trailer exceeds
certain minimums that can vary from state
to state. Read and follow the instructions for
the trailer brakes so they are installed,
adjusted, and maintained properly. Never
attempt to tap into your vehicle's hydraulic
brake system. If you do, both the vehicle
anti-lock brakes and the trailer brakes may
not function, which could result in a crash.
Trailer Wiring Harness
lf equipped, the trailer wiring harness, with
a 7-pin connector is mounted on the trailer
hitch.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
264 Driving and Operating
1. Left Turn/Brake
2. Tail Lamps
3. Reverse Lamps
4. Battery feed
5. Right Turn/Brake
6. Electric Brakes
7. Ground
If the vehicle is not equipped with a trailer
connector on the trailer hitch, a 7-wire
trailering harness is tied to the vehicles
frame. The harness requires the installation
of a trailer connector, which is 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:
Stop/Turn
Signal Left Yellow/Gray
Stop/Turn Signal
Right Green/Violet
Tail/Parking Lamps Gray/Brown
Reverse Lamps White/Green
Battery Feed Red/Green
Ground Black
Electric Trailer Brake Blue Electric Brake Control Wiring Provisions
If equipped, (4) blunt-cut wires are located
near the driver's feet for an aftermarket
electric trailer brake controller as part of the
trailer wiring package. The harness contains
the following circuits:
Electric Trailer
Brakes Blue
Battery Feed Red/Black or
Red/Blue
Brake Apply Signal White/Blue
Ground Black
Refer to the aftermarket electric trailer brake
controller owner's manual to determine wire
color coding of the electric trailer brake
controller. The wire colors on the brake
controller may be different from the vehicle.
It may be necessary to have a technician
connect the 12-volt power to the engine
compartment fuse block. The electric trailer
brake controller should be installed by your
dealer or a qualified service center.
Trailer Lamps
Always check all trailer lamps are working at
the beginning of each trip, and periodically
on longer trips.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 265
Turn Signals When Towing a Trailer
When properly connected, the trailer turn
signals should will illuminate to indicate the
vehicle is turning, changing lanes,
or stopping. When towing a trailer, the
arrows on the instrument cluster will
illuminate even if the trailer is not properly
connected or the bulbs are burned out.
Tow/Haul Mode
For instructions on how to enter Tow/Haul
mode, seeDriver Mode Control 0228.
Tow/Haul assists when pulling a heavy
trailer or a large or heavy load. See Tow/
Haul Mode 0224.
Tow/Haul Mode is designed to be most
effective when the vehicle and trailer
combined weight is at least 75% of the
vehicle's Gross Combined Weight Rating
(GCWR). See “Weight of the Trailer” under
Trailer Towing 0259.
Tow/Haul Mode is most useful when towing
a heavy trailer or carrying a large or
heavy load:
.through rolling terrain
.in stop-and-go traffic
.in busy parking lots Operating the vehicle in Tow/Haul Mode
when lightly loaded or not towing will not
cause damage; however, it is not
recommended and may result in unpleasant
engine and transmission driving
characteristics and reduced fuel economy.
Trailer Sway Control (TSC)
Vehicles with StabiliTrak/Electronic Stability
Control (ESC) have a Trailer Sway Control
(TSC) feature. Trailer sway is unintended
side-to-side motion of a trailer while towing.
If the vehicle is towing a trailer and the TSC
detects that sway is increasing, the vehicle
brakes are selectively applied at each wheel,
to help reduce excessive trailer sway.
If equipped with the Integrated Trailer Brake
Control (ITBC) system, and the trailer has an
electric brake system, StabiliTrak/ESC may
also apply the trailer brakes.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak/ESC warning light
will flash on the instrument cluster. Reduce
vehicle speed by gradually removing your
foot from the accelerator. If trailer sway
continues, StabiliTrak/ESC can reduce engine
torque to help slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned off. See
Traction Control/Electronic Stability Control
0
226.
{Warning
Trailer sway can result in a crash and in
serious injury or death, even if the
vehicle is equipped with TSC.
If the trailer begins to sway, reduce
vehicle speed by gradually removing your
foot from the accelerator. Then pull over
to check the trailer and vehicle to help
correct possible causes, including an
improperly or overloaded trailer,
unrestrained cargo, improper trailer hitch
configuration, or improperly inflated or
incorrect vehicle or trailer tires. See
Towing Equipment 0262 for trailer
ratings and hitch setup recommendations.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Vehicle Care 267
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 268
California Proposition 65 Warning . . . . . 268
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . 268
Accessories and Modifications . . . . . . . . . 268
Vehicle Checks
Doing Your Own Service Work . . . . . . . . 269
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Engine Compartment Overview . . . . . . . . 271
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Engine Oil Life System . . . . . . . . . . . . . . . . 278
Automatic Transmission Fluid . . . . . . . . . 279
Engine Air Filter Life System . . . . . . . . . . 279
Engine Air Cleaner/Filter . . . . . . . . . . . . . . 279
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 281
Engine Overheating . . . . . . . . . . . . . . . . . . . 285
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Battery - North America . . . . . . . . . . . . . . . 288
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . 289
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Wiper Blade Replacement . . . . . . . . . . . . . 290
Windshield Replacement . . . . . . . . . . . . . . 290
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 292
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 292
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 292
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
Electrical System
Electrical System Overload . . . . . . . . . . . . 292
Fuses and Circuit Breakers . . . . . . . . . . . . . 293
Engine Compartment Fuse Block . . . . . . 293
Instrument Panel Fuse Block . . . . . . . . . . 296
Rear Compartment Fuse Block . . . . . . . . . 298
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 301
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
Summer Tires . . . . . . . . . . . . . . . . . . . . . . . . . 302
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . 302
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 302
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 304
Tire Terminology and Definitions . . . . . 304
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Tire Pressure Monitor System . . . . . . . . . 309
Tire Pressure Monitor Operation . . . . . . . 310
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . . 313
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 When It Is Time for New Tires . . . . . . . . . 314
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . 315
Different Size Tires and Wheels . . . . . . . . 316
Uniform Tire Quality Grading . . . . . . . . . . 316
Wheel Alignment and Tire Balance . . . . 318
Wheel Replacement . . . . . . . . . . . . . . . . . . . 318
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 319
Tire Sealant and Compressor Kit . . . . . . 320
Storing the Tire Sealant and
Compressor Kit . . . . . . . . . . . . . . . . . . . . . . 326
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 326
Compact Spare Tire . . . . . . . . . . . . . . . . . . . . 331
Jump Starting
Jump Starting - North America . . . . . . . . 332
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 334
Recreational Vehicle Towing . . . . . . . . . . . 335
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
268 Vehicle Care
General Information
For service and parts needs, visit your
dealer. You will receive genuine GM parts
and GM-trained and supported service
people.
Genuine GM parts have one of these marks:
California Proposition 65 Warning
{Warning
Most motor vehicles, including this one,
as well as many of its service parts and
fluids, contain and/or emit chemicals
known to the State of California to cause
cancer and birth defects or other
reproductive harm. Engine exhaust, many
parts and systems, many fluids, and
some component wear by-products
contain and/or emit these chemicals. For
more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
See Battery - North America 0288 and
Jump Starting - North America 0332 and the
back cover.
California Perchlorate Materials
Requirements
Certain types of automotive applications,
such as airbag initiators, seat belt
pretensioners, and lithium batteries
contained in electronic keys, may contain
perchlorate materials. Perchlorate Material –
special handling may apply. See
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and Modifications
Adding non-dealer accessories or making
modifications to the vehicle can affect
vehicle performance and safety, including
such things as airbags, braking, stability,
ride and handling, emissions systems,
aerodynamics, durability, and electronic
systems like antilock brakes, traction control,
and stability control. These accessories or
modifications could even cause malfunction
or damage not covered by the vehicle
warranty.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
272 Vehicle Care
1.Engine Air Cleaner/Filter 0279.
2. Engine Oil Fill Cap. See Engine Oil0276.
3. Engine Oil Dipstick. See Engine Oil0276.
4. Engine Cooling Fan (Out of View). See Cooling System 0281.
5. Brake Fluid Reservoir. See Brake Fluid
0 287.
6. Battery - North America 0288.
7. Engine Coolant Surge Tank and Pressure Cap. See Cooling System 0281.
8. Positive (+) Battery Terminal (Under Cover). See Jump Starting - North
America 0332.
9. Windshield Washer Fluid Reservoir. See Washer Fluid 0286.
10. Engine Compartment Fuse Block 0293.
11. Remote Negative (-) Battery Terminal. SeeJump Starting - North America 0332.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
274 Vehicle Care
1.Engine Air Cleaner/Filter 0279.
2. Engine Oil Fill Cap. See Engine Oil0276.
3. Engine Oil Dipstick. See Engine Oil0276.
4. Engine Cooling Fan (Out of View). See Cooling System 0281.
5. Windshield Washer Fluid Reservoir. See Washer Fluid 0286.
6. Brake Fluid Reservoir. See Brake Fluid
0 287.
7. Battery - North America 0288.
8. Engine Coolant Surge Tank and Pressure Cap. See Cooling System 0281.
9. Positive (+) Battery Terminal (Under Cover). See Jump Starting - North
America 0332.
10. Engine Compartment Fuse Block 0293.
11. Remote Negative (-) Battery Terminal. SeeJump Starting - North America 0332.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
276 Vehicle Care
1.Engine Air Cleaner/Filter 0279.
2. Engine Oil Fill Cap. See Engine Oil0276.
3. Engine Oil Dipstick. See Engine Oil0276.
4. Engine Cooling Fan (Out of View). See Cooling System 0281.
5. Windshield Washer Fluid Reservoir. See Washer Fluid 0286.
6. Brake Fluid Reservoir. See Brake Fluid
0 287.
7. Battery - North America 0288.
8. Engine Coolant Surge Tank and Pressure Cap. See Cooling System 0281.
9. Positive (+) Battery Terminal. See Jump
Starting - North America 0332.
10. Engine Compartment Fuse Block 0293.
11. Remote Negative (-) Battery Terminal. SeeJump Starting - North America 0332.Engine Oil
To ensure proper engine performance and
long life, careful attention must be paid to
engine oil. Following these simple, but
important steps will help protect your
investment:
.Use engine oil approved to the proper
specification and of the proper viscosity
grade. See “Selecting the Right Engine
Oil” in this section.
.Check the engine oil level regularly and
maintain the proper oil level. See
“Checking Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the appropriate
time. SeeEngine Oil Life System 0278.
.Always dispose of engine oil properly. See
“What to Do with Used Oil” in this
section.
Checking Engine Oil
Check the engine oil level regularly, every
650 km (400 mi), especially prior to a long
trip. The engine oil dipstick handle is a loop.
See Engine Compartment Overview 0271 for
the location.
{Warning
The engine oil dipstick handle may be
hot; it could burn you. Use a towel or
glove to touch the dipstick handle.
If a low oil Driver Information Center (DIC)
message displays, check the oil level.
Follow these guidelines:
.To get an accurate reading, park the
vehicle on level ground. Check the engine
oil level after the engine has been off for
at least two hours. Checking the engine
oil level on steep grades or too soon after
engine shutoff can result in incorrect
readings. Accuracy improves when
checking a cold engine prior to starting.
Remove the dipstick and check the level.
.If unable to wait two hours, the engine
must be off for at least 15 minutes if the
engine is warm, or at least 30 minutes if
the engine is not warm. Pull out the
dipstick, wipe it with a clean paper towel
or cloth, then push it back in all the way.
Remove it again, keeping the tip down,
and check the level.