2021 GMC TERRAIN climate control

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
184 Climate Controls
During service, all refrigerants should be
reclaimed with proper equipment. Venting
refrigerants directly to the atmosphere is
harmful to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite, or other
health-based concerns.
The air conditioning system requires periodic
maintenance. SeeMaintenance Schedule
0 331.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 187
Driving for Better Fuel Economy
Driving habits can affect fuel mileage. Here
are some driving tips to get the best fuel
economy possible:
.Set the climate controls to the desired
temperature after the engine is started,
or turn them off when not required.
.Avoid fast starts and accelerate smoothly.
.Brake gradually and avoid abrupt stops.
.Avoid idling the engine for long periods
of time.
.When road and weather conditions are
appropriate, use cruise control.
.Always follow posted speed limits or
drive more slowly when conditions
require.
.Keep vehicle tires properly inflated.
.Combine several trips into a single trip.
.Replace the vehicle's tires with the same
TPC Spec number molded into the tire's
sidewall near the size.
.Follow recommended scheduled
maintenance.
Distracted Driving
Distraction comes in many forms and can
take your focus from the task of driving.
Exercise good judgment and do not let other
activities divert your attention away from
the road. Many local governments have
enacted laws regarding driver distraction.
Become familiar with the local laws in
your area.
To avoid distracted driving, keep your eyes
on the road, keep your hands on the
steering wheel, and focus your attention on
driving.
.Do not use a phone in demanding driving
situations. Use a hands-free method to
place or receive necessary phone calls.
.Watch the road. Do not read, take notes,
or look up information on phones or
other electronic devices.
.Designate a front seat passenger to
handle potential distractions.
.Become familiar with vehicle features
before driving, such as programming
favorite radio stations and adjusting
climate control and seat settings. Program
all trip information into any navigation
device prior to driving.
.Wait until the vehicle is parked to
retrieve items that have fallen to the
floor.
.Stop or park the vehicle to tend to
children.
.Keep pets in an appropriate carrier or
restraint.
.Avoid stressful conversations while
driving, whether with a passenger or on a
cell phone.
{Warning
Taking your eyes off the road too long or
too often could cause a crash resulting in
injury or death. Focus your attention on
driving.
Refer to the infotainment section for more
information on using that system and the
navigation system, if equipped, including
pairing and using a cell phone.
Defensive Driving
Defensive driving means “always expect the
unexpected.” The first step in driving
defensively is to wear the seat belt. See
Seat Belts 040.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 195
.Allow greater following distance and
watch for slippery spots. Icy patches can
occur on otherwise clear roads in shaded
areas. The surface of a curve or an
overpass can remain icy when the
surrounding roads are clear. Avoid sudden
steering maneuvers and braking while
on ice.
.Turn off cruise control.
Blizzard Conditions
Stop the vehicle in a safe place and signal
for help. Stay with the vehicle unless there
is help nearby. If possible, use Roadside
Assistance. SeeRoadside Assistance Program
0 349. To get help and keep everyone in the
vehicle safe:
.Turn on the hazard warning flashers.
.Tie a red cloth to an outside mirror.
{Warning
Snow can trap engine exhaust under the
vehicle. This may cause exhaust gases to
get inside. Engine exhaust contains
carbon monoxide (CO), which cannot be
seen or smelled. It can cause
unconsciousness and even death.
(Continued)
Warning (Continued)
If the vehicle is stuck in snow:
.Clear snow from the base of the
vehicle, especially any blocking the
exhaust pipe.
.Open a window about 5 cm (2 in) on
the vehicle side that is away from the
wind, to bring in fresh air.
.Fully open the air outlets on or under
the instrument panel.
.Adjust the climate control system to
circulate the air inside the vehicle and
set the fan speed to the highest
setting. See“Climate Control Systems.”
For more information about CO, see
Engine Exhaust 0207.
To save fuel, run the engine for short
periods to warm the vehicle and then shut
the engine off and partially close the
window. Moving about to keep warm also
helps.
If it takes time for help to arrive, when
running the engine, push the accelerator
pedal slightly so the engine runs faster than
the idle speed. This keeps the battery charged to restart the vehicle and to signal
for help with the headlamps. Do this as
little as possible, to save fuel.
If the Vehicle Is Stuck
Slowly and cautiously spin the wheels to
free the vehicle when stuck in sand, mud,
ice, or snow.
If stuck too severely for the traction system
to free the vehicle, turn the traction system
off and use the rocking method. See
Traction Control/Electronic Stability Control
0
214.
{Warning
If the vehicle's tires spin at high speed,
they can explode, and you or others
could be injured. The vehicle can
overheat, causing an engine compartment
fire or other damage. Spin the wheels as
little as possible and avoid going above
56 km/h (35 mph).
Rocking the Vehicle to Get it Out
Turn the steering wheel left and right to
clear the area around the front wheels. Turn
off any traction system. Shift back and forth
between R (Reverse) and a low forward gear,

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
202 Driving and Operating
the brake pedal is released or the
accelerator pedal is pressed, the engine will
restart.
To maintain vehicle performance, other
conditions may cause the engine to
automatically restart before the brake pedal
is released.
Auto Stops may not occur and/or auto
restarts may occur because:
.The climate control settings require the
engine to be running to cool or heat the
vehicle interior.
.The vehicle battery charge is low.
.The vehicle battery has recently been
disconnected.
.Minimum vehicle speed has not been
reached since the last Auto Stop
.The accelerator pedal is pressed.
.The engine or transmission is not at the
required operating temperature.
.The outside temperature is not in the
required operating range.
.The vehicle is shifted out of D (Drive) to
any gear other than P (Park).
.Tow/Haul Mode or other driver modes
have been selected.
.The vehicle is on a steep hill or grade.
.The driver door has been opened or driver
seat belt has been unbuckled.
.The hood has been opened.
.The Auto Stop has reached the maximum
allowed time.
Winter Cover
If equipped, the winter cover can be used to
enhance heater performance in extremely
cold conditions below−0 °C (32 °F). The
winter cover installs over the grille and
restricts airflow to the engine compartment.
Usage Guidelines
The winter cover should only be used while
operating the vehicle in extremely cold
temperatures or in heavy snow for extended
periods. In these temperatures, the vehicle
does not need a large amount of air to
properly cool the engine. When more
airflow is required to cool the vehicle, the
winter cover should not be used. The
following usage guidelines will allow
adequate airflow for proper radiator and air
cooler performance:
.Do not use the winter cover if towing a
trailer. The vehicle may overheat if the
radiator is covered while towing.
.Do not modify the cover. The winter
cover does not cover some sections of the
front of the vehicle to provide enough
airflow.
.Keep the underside of the winter cover as
clean as possible. Remove monthly or as
necessary and clean away dust and
debris.
.Do not use the winter cover above −0 °C
(32 °F).
Use only a mild soap to clean. Do not use
harsh soap, strong detergents, or vinyl
protectant/sealant type products as they
may damage the special finish. Allow the
winter cover to dry completely before
reinstalling.
Installation Instructions
When first trying to fit the cover, it may
appear to be undersized but will stretch
during installation to ensure a tight fit. The
initial installation of the cover is best
performed when the winter cover is warm.

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
302 Vehicle Care
conditions on a specified government
test course. For example, a tire graded
150 would wear one and one-half (1½)
times as well on the government course
as a tire graded 100. The relative
performance of tires depends upon the
actual conditions of their use, however,
and may depart significantly from the
norm due to variations in driving habits,
service practices and differences in road
characteristics and climate.
Traction
The traction grades, from highest to
lowest, are AA, A, B, and C. Those
grades represent the tire's ability to
stop on wet pavement as measured
under controlled conditions on specified
government test surfaces of asphalt and
concrete. A tire marked C may have
poor traction performance. Warning:
The traction grade assigned to this tire
is based on straight-ahead braking
traction tests, and does not include
acceleration, cornering, hydroplaning,
or peak traction characteristics.Temperature
The temperature grades are A (the
highest), B, and C, representing the
tire's resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled conditions
on a specified indoor laboratory test
wheel. Sustained high temperature can
cause the material of the tire to
degenerate and reduce tire life, and
excessive temperature can lead to
sudden tire failure. The grade C
corresponds to a level of performance
which all passenger car tires must meet
under the Federal Motor Safety
Standard No. 109. Grades B and A
represent higher levels of performance
on the laboratory test wheel than the
minimum required by law. Warning:
The temperature grade for this tire is
established for a tire that is properly
inflated and not overloaded. Excessive
speed, underinflation, or excessive
loading, either separately or in
combination, can cause heat buildup
and possible tire failure.Wheel Alignment and Tire
Balance
The tires and wheels were aligned and
balanced at the factory to provide the
longest tire life and best overall
performance. Adjustments to wheel
alignment and tire balancing are not
necessary on a regular basis. Consider an
alignment check if there is unusual tire wear
or the vehicle is significantly pulling to one
side or the other. Some slight pull to the
left or right, depending on the crown of the
road and/or other road surface variations
such as troughs or ruts, is normal. If the
vehicle is vibrating when driving on a
smooth road, the tires and wheels may
need to be rebalanced. See your dealer for
proper diagnosis.
Wheel Replacement
Replace any wheel that is bent, cracked,
or badly rusted or corroded. If wheel nuts
keep coming loose, the wheel, wheel bolts,
and wheel nuts should be replaced. If the
wheel leaks air, replace it. Some aluminum
wheels can be repaired. See your dealer if
any of these conditions exist.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/-
Mexico-14420055) - 2021 - CRC - 11/13/20
366 Index
Auto StopStop/Start System . . . . . . . . . . . . . . . . . . . . . 201
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . . . . . . . . 25
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Emergency Braking (AEB) . . . . . . . . . . . . . . 239
Headlamp System . . . . . . . . . . . . . . . . . . . . . . 118
Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Transmission Fluid . . . . . . . . . . . . . . . . . . . . . 265
Automatic Transmission Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Avoiding Untrusted Media Devices . . . . . . . .134
B
Battery Exterior Lighting Battery Saver . . . . . . . . 122
Load Management . . . . . . . . . . . . . . . . . . . . . . 121
Power Protection . . . . . . . . . . . . . . . . . . . . . . 122
Battery - North America . . . . . . . . . . . . . 273, 316
Blade Replacement, Wiper . . . . . . . . . . . . . . . 275
Bluetooth Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 155, 156
Bluetooth Audio . . . . . . . . . . . . . . . . . . . . . . . . . 136
Brake Parking, Electric . . . . . . . . . . . . . . . . . . . . . . . . 212
System Warning Light . . . . . . . . . . . . . . . . . . 95
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 Antilock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Brakes (cont'd)
Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Automatic Emergency (AEB) . . . . . . . . . . . 239
Braking System Front Pedestrian (FPB) . . . . . . . . . . . . . . . . . 240
Break-In, New Vehicle . . . . . . . . . . . . . . . . . . . . 199
Bulb Replacement Front Turn Signal Lamps . . . . . . . . . . . . . . . 278
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 277
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . 277
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
High Intensity Discharge (HID)Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
License Plate Lamps . . . . . . . . . . . . . . . . . . . 279
Taillamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . . . 300
C
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
California Perchlorate Materials Requirements . . . 258
California Proposition 65 Warning . . . . . . . . . . . . . . . . . . .258, 273, 316, Back Cover
Canadian Vehicle Owners . . . . . . . . . . . . . . . . . . . 1
Capacities and Specifications . . . . . . . . . . . . . 343 Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 207
Liftgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 194
Cargo Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Tie-Downs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Caution, Danger, and Warning . . . . . . . . . . . . . .2
Center Console Storage . . . . . . . . . . . . . . . . . . . .75
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Charging System Light . . . . . . . . . . . . . . . . . . . . 93
Check Engine Light (Malfunction Indicator) . . . . 93
Child Restraints
Infants and Young Children . . . . . . . . . . . . . 58
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Securing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69, 70
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Cleaning Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Climate Control Systems . . . . . . . . . . . . . . . . . .178 Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . 178

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/-
Mexico-14420055) - 2021 - CRC - 11/13/20
Index 367
Climate Control Systems (cont'd)Dual Automatic . . . . . . . . . . . . . . . . . . . . . . . . 180
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
Cluster, Instrument . . . . . . . . . . . . . . . . . . . 85, 88
Collision Damage Repair . . . . . . . . . . . . . . . . . 352
Compact Spare Tire . . . . . . . . . . . . . . . . . . . . . . . 315
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
Compressor Kit, Tire Sealant . . . . . . . . . . . . . 305
Connected Services Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 363
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364
Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362
Connections
Connected Services . . . . . . . . . . . . . . . . . . . . 363
Control Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Traction and Electronic Stability . . . . . . . 214
Control Light
Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Control of a Vehicle . . . . . . . . . . . . . . . . . . . . . 188
Controls Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . 126
Convenience Net . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Coolant
Engine Temperature Gauge . . . . . . . . . . . . . 91
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178, 180
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Courtesy Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Courtesy Transportation Program . . . . . . . . . 351
Cover Cargo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Coverage Explanations . . . . . . . . . . . . . . . . . . . 150
Covers Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Cruise Control, Adaptive . . . . . . . . . . . . . . . . . 222
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Customer Assistance . . . . . . . . . . . . . . . . . . . . . 348 Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Text Telephone (TTY) Users . . . . . . . . . . . . 348
Customer Information Publications Ordering Information . . . . . 353
Customer Satisfaction Procedure . . . . . . . . . 346
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
D
Damage Repair, Collision . . . . . . . . . . . . . . . . . 352
Danger, Warning, and Caution . . . . . . . . . . . . . .2
Data Collection
Infotainment System . . . . . . . . . . . . . . . . . . 356 Data Collection (cont'd)
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Data Recorders, Event . . . . . . . . . . . . . . . . . . . 356
Database Coverage Explanations . . . . . . . . . 150
Daytime Running Lamps (DRL) . . . . . . . . . . . . 118
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . . . .187
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .142
Diagnostics Connected Services . . . . . . . . . . . . . . . . . . . . 364
Distracted Driving . . . . . . . . . . . . . . . . . . . . . . . . .187
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Door Ajar Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 16
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Power Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Drive Belt Routing, Engine . . . . . . . . . . . . . . . 345
Drive Systems All-Wheel Drive . . . . . . . . . . . . . . . . . . . . 212, 274
Driver
Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Driver Assistance Systems . . . . . . . . . . . . . . . . 231
Driver Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Driver Information Center (DIC) . . . . . 100, 105
Driver Mode Control . . . . . . . . . . . . . . . . . . . . . .218
Driving Assistance Systems . . . . . . . . . . . . . . . . . . . . 237