2021 GMC TERRAIN brakes

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 249
Driving Characteristics and
Towing Tips
{Warning
You can lose control when towing a
trailer if the correct equipment is not
used or the vehicle is not driven properly.
For example, if the trailer is too heavy or
the trailer brakes are inadequate for the
load, the vehicle may not stop as
expected. You and others could be
seriously injured. The vehicle may also be
damaged, and the repairs would not be
covered by the vehicle warranty. Pull a
trailer only if all the steps in this section
have been followed. Ask your dealer for
advice and information about towing a
trailer with the vehicle.
Driving with a Trailer
Trailering is different than just driving the
vehicle by itself. Trailering means changes in
handling, acceleration, braking, durability,
and fuel economy. Successful, safe trailering
takes correct equipment, and it has to be
used properly.The following information has many
time-tested, important trailering tips and
safety rules. Many of these are important
for your safety and that of your passengers.
Read this section carefully before pulling a
trailer.
When towing a trailer:
.Become familiar with and follow all state
and local laws that apply to trailer
towing. These requirements vary from
state to state.
.State laws may require the use of
extended side view mirrors. Even if not
required, you should install extended side
view mirrors if your visibility is limited or
restricted while towing.
.Do not tow a trailer during the first
800 km (500 mi) of vehicle use to prevent
damage to the engine, axle, or other
parts.
.It is recommended to perform the first oil
change before heavy towing.
.During the first 800 km (500 mi) of trailer
towing, do not drive over 80 km/h
(50 mph) and do not make starts at full
throttle.
.Vehicles can tow in D (Drive). If the
transmission downshifts too often, a
lower gear may be selected using Manual
Mode See
Manual Mode 0211.
If equipped, the following driver assistance
features should be turned off when towing
a trailer:
.Adaptive Cruise Control (ACC)
.Super Cruise Control
.Lane Keep Assist (LKA)
.Park Assist
.Automatic Parking Assist (APA)
.Reverse Automatic Braking (RAB)
If equipped, the following driver assistance
features should be turned to alert or off
when towing a trailer:
.Automatic Emergency Braking (AEB)
.Intelligent Brake Assist (IBA)
.Front Pedestrian Braking (FPB)
If equipped with Lane Change Alert (LCA),
the LCA detection zones that extend back
from the side of the vehicle do not move
further back when a trailer is towed. Use
caution while changing lanes when towing a
trailer.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
250 Driving and Operating
If equipped with Rear Cross Traffic Alert
(RCTA), use caution while backing up when
towing a trailer, as the RCTA detection zones
that extend out from the back of the vehicle
do not move further back when a trailer is
towed.
{Warning
To prevent serious injury or death from
carbon monoxide (CO), 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.
.Adjust the climate control system to a
setting that brings in only outside air.
See“Climate Control Systems” in the
Index.
For more information about carbon
monoxide, see Engine Exhaust 0207.
Towing a trailer requires experience. The
combination of the vehicle and trailer is
longer and not as responsive as the vehicle
itself. Get used to the handling and braking
of the combination by driving on a level
road surface before driving on public roads. The trailer structure, the tires, and the
brakes must be all be rated to carry the
intended cargo. Inadequate trailer
equipment can cause the combination to
operate in an unexpected or unsafe manner.
Before driving, inspect all trailer hitch parts
and attachments, safety chains, electrical
connectors, lamps, tires, and mirrors. See
Towing Equipment
0254. If the trailer has
electric brakes, start the combination
moving and then manually apply the trailer
brake controller to check that the trailer
brakes work. During the trip, occasionally
check that the cargo and trailer are secure
and that the lamps and any trailer brakes
are working.Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.
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 that hand to the
right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Caution
Turn more slowly and make wider arcs
when towing a trailer to prevent damage
to your vehicle. Making very sharp turns
could cause the trailer to contact the
vehicle.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 251
Make wider turns than normal when towing,
so trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency.
The vehicle can tow in D (Drive). Shift the
transmission to a lower gear if the
transmission shifts too often under heavy
loads and/or hilly conditions.
When towing at higher altitudes, engine
coolant will boil at a lower temperature
than at lower 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. To avoid this, let the engine
run, 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, seeEngine
Overheating 0270.
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 0331. It is especially important to
check the automatic transmission fluid,
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 0270.
Trailer Towing
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
(Continued)

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
252 Driving and Operating
Caution (Continued)
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.
Trailer Weight Ratings
When towing a trailer, the combined weight
of the vehicle, vehicle contents, trailer, and
trailer contents must be below all of the
maximum weight ratings for the vehicle,
including:
.GCWR: Gross Combined Weight Rating
.GVWR: Gross Vehicle Weight Rating
.Maximum Trailer Weight Rating
.Maximum Trailer Tongue Weight Rating See
“Trailer Brakes” underTowing
Equipment 0254 to determine if brakes are
required based on your trailer's 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 0196. 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
The maximum trailer weight rating is
calculated assuming the tow vehicle has a
driver, a front seat passenger, and all
required trailering equipment. This value
represents the heaviest trailer the vehicle
can tow, but it may be necessary to reduce
the trailer weight to stay within the GCW,
GVWR, maximum trailer tongue load,
or GAWR-RR for the vehicle.
Use the tow rating chart to determine how
much the trailer can weigh, based on the
vehicle model and options.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 253
VehicleMaximum Trailer Weight
with Trailer Brakes† GCWR*
1.5L Gas FWD 680 kg (1,500 lb) 2 380 kg (5,247 lb)
1.5L Gas AWD 680 kg (1,500 lb) 2 480 kg (5,467 lb)
† For trailers without trailer brakes the maximum trailer weight is 454 kg (1,000 lb). See
Towing Equipment 0254.
* 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. Do not exceed the GCWR for the vehicle.
Maximum Trailer Tongue Weight
The Maximum Trailer Tongue Weight Rating
is the allowable trailer tongue weight that
the vehicle can support using a conventional
trailer hitch. It may be necessary to reduce
the overall trailer weight to stay within the
maximum trailer tongue weight rating while
still maintaining the correct trailer load
balance.
Do not exceed a maximum trailer tongue
weight of 159 kg (350 lb). The trailer tongue weight contributes to the
Gross Vehicle Weight (GVW). GVW includes
the CURB WEIGHT of your vehicle, any
passengers, cargo, equipment and the trailer
tongue weight. Vehicle options, passengers,
cargo, and equipment reduce the maximum
allowable tongue weight the vehicle can
carry, which also reduces the maximum
allowable trailer weight.
Trailer Load Balance
The correct trailer load balance must be
maintained to ensure trailer stability.
Incorrect load balance is a leading cause of
trailer sway.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 255
.Tires must be properly inflated to support
loads while towing a trailer. SeeTires
0 287 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 Lamps
Always check all trailer lamps are working at
the beginning of each trip, and periodically
on longer trips.
Turn Signals When Towing a Trailer
When properly connected, the trailer turn
signals 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.
Trailer Tires
Special Trailer (ST) tires differ from vehicle
tires. Trailer tires are designed with stiff
sidewalls to help prevent sway and tosupport heavy loads. These features can
make it difficult to determine if the trailer
tire pressures are low only based on a visual
inspection.
Always check all trailer tire pressures before
each trip when the tires are cool. Low trailer
tire pressure is a leading cause of trailer tire
blow-outs.
Trailer tires deteriorate over time. The trailer
tire sidewall will show the week and year
the tire was manufactured. Many trailer tire
manufacturers recommend replacing tires
more than six years old.
Overloading is another leading cause of
trailer tire blow-outs. Never load your trailer
with more weight than the tires are
designed to support. The load rating is
located on the trailer tire sidewall.
Always know the maximum speed rating for
the trailer tires before driving. This may be
significantly lower than the vehicle tire
speed rating. The speed rating may be on
the trailer tire sidewall. If the speed rating is
not shown, the default trailer tire speed
rating is 105 km/h (65 mph).

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Vehicle Care 257
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 258
California Proposition 65 Warning . . . . . 258
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 258
Accessories and Modifications . . . . . . . . . 258
Vehicle Checks
Doing Your Own Service Work . . . . . . . . 259
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Engine Compartment Overview . . . . . . . . 261
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Engine Oil Life System . . . . . . . . . . . . . . . . 264
Automatic Transmission Fluid . . . . . . . . . 265
Engine Air Filter Life System . . . . . . . . . . 265
Engine Air Cleaner/Filter . . . . . . . . . . . . . . 265
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 267
Engine Overheating . . . . . . . . . . . . . . . . . . . 270
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Battery - North America . . . . . . . . . . . . . . . 273
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . 274
Starter Switch Check . . . . . . . . . . . . . . . . . . 274
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Wiper Blade Replacement . . . . . . . . . . . . . 275
Windshield Replacement . . . . . . . . . . . . . . 276 Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 277
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 277
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 277
High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Front Turn Signal Lamps . . . . . . . . . . . . . . . 278
Taillamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
License Plate Lamp . . . . . . . . . . . . . . . . . . . . 279
Electrical System
Electrical System Overload . . . . . . . . . . . . 280
Fuses and Circuit Breakers . . . . . . . . . . . . 280
Engine Compartment Fuse Block . . . . . . . 281
Instrument Panel Fuse Block . . . . . . . . . . 284
Rear Compartment Fuse Block . . . . . . . . . 285
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 287
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Summer Tires . . . . . . . . . . . . . . . . . . . . . . . . . 288
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 288
Tire Designations . . . . . . . . . . . . . . . . . . . . . 290
Tire Terminology and Definitions . . . . . . 291
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Tire Pressure Monitor System . . . . . . . . . 294 Tire Pressure Monitor Operation . . . . . . 295
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 298
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 298
When It Is Time for New Tires . . . . . . . . 299
Buying New Tires . . . . . . . . . . . . . . . . . . . . . 300
Different Size Tires and Wheels . . . . . . . 301
Uniform Tire Quality Grading . . . . . . . . . . 301
Wheel Alignment and Tire Balance . . . . 302
Wheel Replacement . . . . . . . . . . . . . . . . . . . 302
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 303
Tire Sealant and Compressor Kit . . . . . . 305
Storing the Tire Sealant and
Compressor Kit . . . . . . . . . . . . . . . . . . . . . . 310
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 310
Compact Spare Tire . . . . . . . . . . . . . . . . . . . . 315
Jump Starting
Jump Starting - North America . . . . . . . . 316
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 318
Recreational Vehicle Towing . . . . . . . . . . . 320
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
258 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(Continued)
Warning (Continued)
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 0273 and
Jump Starting - North America 0316 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.
Damage to suspension components caused
by modifying vehicle height outside of
factory settings will not be covered by the
vehicle warranty.
Damage to vehicle components resulting
from modifications or the installation or use
of non-GM certified parts, including control
module or software modifications, is not
covered under the terms of the vehicle
warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to complement
and function with other systems on the
vehicle. See your dealer to accessorize the
vehicle using genuine GM Accessories
installed by a dealer technician.