maintenance GMC TERRAIN 2021 Owner's Manual

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Keys, Doors, and Windows . . . . . . . . . . . . . . . 6
Seats and Restraints . . . . . . . . . . . . . . . . . . . . . 29
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Instruments and Controls . . . . . . . . . . . . . . . . 78
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Infotainment System . . . . . . . . . . . . . . . . . . . 123
Climate Controls . . . . . . . . . . . . . . . . . . . . . . . . 178
Driving and Operating . . . . . . . . . . . . . . . . . . 185
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Service and Maintenance . . . . . . . . . . . . . . . 330
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . 342
Customer Information . . . . . . . . . . . . . . . . . . 346
Reporting Safety Defects . . . . . . . . . . . . . . . 354
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Connected Services . . . . . . . . . . . . . . . . . . . . . 362
Index . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Introduction
The names, logos, emblems, slogans, vehicle
model names, and vehicle body designs
appearing in this manual including, but not
limited to, GM, the GM logo, GMC, the GMC
Truck Emblem, TERRAIN, and DENALI are
trademarks and/or service marks of General
Motors LLC, its subsidiaries, affiliates,
or licensors.
For vehicles first sold in Canada, substitute
the name“General Motors of Canada
Company” for GMC Motor Division wherever
it appears in this manual.
This manual describes features that may or
may not be on the vehicle because of
optional equipment that was not purchased
on the vehicle, model variants, country
specifications, features/applications that may not be available in your region, or changes
subsequent to the printing of this owner’s
manual.
Refer to the purchase documentation
relating to your specific vehicle to confirm
the features.
Keep this manual in the vehicle for quick
reference.Canadian Vehicle Owners
A French language manual can be obtained
from your dealer, at www.helminc.com,
or from:
Propriétaires Canadiens
On peut obtenir un exemplaire de ce guide
en français auprès du concessionnaire ou à
l'adresse suivante:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
USA
Litho in U.S.A.
Part No. 84443536 B Second Printing©2020 General Motors LLC. All Rights Reserved.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
56 Seats and Restraints
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the vehicle's
frame, bumper system, height, front end,
or side sheet metal may keep the airbag
system from working properly.
The operation of the airbag system can also
be affected by changing, including
improperly repairing or replacing, any parts
of the following:
.Airbag system, including airbag modules,
front or side impact sensors, sensing and
diagnostic module, or airbag wiring
.Front seats, including stitching, seams or
zippers
.Seat belts
.Steering wheel, instrument panel,
overhead console, ceiling trim, or pillar
garnish trim
.Inner door seals, including speakers
Your dealer and the service manual have
information about the location of the airbag
modules and sensors, sensing and diagnostic
module, and airbag wiring along with the
proper replacement procedures. In addition, the vehicle has a passenger
sensing system for the front outboard
passenger position, which includes sensors
that are part of the passenger seat. The
passenger sensing system may not operate
properly if the original seat trim is replaced
with non-GM covers, upholstery, or trim; or
with GM covers, upholstery, or trim
designed for a different vehicle. Any object,
such as an aftermarket seat heater or a
comfort-enhancing pad or device, installed
under or on top of the seat fabric, could
also interfere with the operation of the
passenger sensing system. This could either
prevent proper deployment of the passenger
airbag(s) or prevent the passenger sensing
system from properly turning off the
passenger airbag(s). See
Passenger Sensing
System 052.
If the vehicle has rollover roof-rail airbags,
see Different Size Tires and Wheels 0301 for
additional important information.
If the vehicle must be modified because you
have a disability and have questions about
whether the modifications will affect the
vehicle's airbag system, or if you have
questions about whether the airbag system will be affected if the vehicle is modified for
any other reason, call Customer Assistance.
See
Customer Assistance Offices 0348.
Airbag System Check
The airbag system does not need regularly
scheduled maintenance or replacement.
Make sure the airbag readiness light is
working. See Airbag Readiness Light 092.
Caution
If an airbag covering is damaged, opened,
or broken, the airbag may not work
properly. Do not open or break the airbag
coverings. If there are any opened or
broken airbag coverings, have the airbag
covering and/or airbag module replaced.
For the location of the airbags, see Where
Are the Airbags? 048. See your dealer
for service.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
94 Instruments and Controls
Caution (Continued)
run smoothly. This could lead to costly
repairs that might not be covered by the
vehicle warranty.
Caution
Modifications to the engine, transmission,
exhaust, intake, or fuel system, or the
use of replacement tires that do not
meet the original tire specifications, can
cause this light to come on. This could
lead to costly repairs not covered by the
vehicle warranty. This could also affect
the vehicle’s ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications0258.
Light Flashing
If the light is flashing : A malfunction has
been detected that could damage the
emission control system and increase vehicle
emissions. Diagnosis and service may be
required. To help prevent damage, reduce vehicle
speed and avoid hard accelerations and
uphill grades. If towing a trailer, reduce the
amount of cargo being hauled as soon as
possible.
If the light continues to flash, find a safe
place to park. Turn the vehicle off and wait
at least 10 seconds before restarting the
engine. If the light is still flashing, follow
the previous guidelines and see your dealer
for service as soon as possible.
Light on Steady
If the light is on steady :
A malfunction has
been detected. Diagnosis and service may be
required.
Check the following:
.If fuel has been added to the vehicle
using the capless funnel adapter, make
sure that it has been removed. See
“Filling the Tank with a Portable Gas Can”
under Filling the Tank 0247. The
diagnostic system can detect if the
adapter has been left installed in the
vehicle, allowing fuel to evaporate into
the atmosphere. A few driving trips with
the adapter removed may turn off the
light.
.Poor fuel quality can cause inefficient
engine operation and poor driveability,
which may go away once the engine is
warmed up. If this occurs, change the fuel
brand. It may require at least one full
tank of the proper fuel to turn the light
off. See Recommended Fuel (LYX - 1.5L L4
Turbo Engine) 0246.
If the light remains on, see your dealer.
Emissions Inspection and Maintenance
Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument panel to
the left of the steering wheel. Connecting
devices that are not used to perform an
Emissions Inspection/Maintenance test or to
service the vehicle may affect vehicle

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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98 Instruments and Controls
If the StabiliTrak/ESC and TCS are off, the
system does not assist in controlling the
vehicle. Turn on the TCS and the StabiliTrak/
ESC systems and the warning light turns off.
SeeTraction Control/Electronic Stability
Control 0214.
Traction Control System (TCS)/
StabiliTrak Light
This light comes on briefly when the vehicle
is turned on.
If the light does not come on, have the
vehicle serviced by your dealer. If the
system is working normally, the indicator
light turns off.
If the light is on and not flashing, the TCS
and potentially the StabiliTrak/ESC system
are not fully operational and may not assist
in maintaining control. Adjust driving
accordingly. If the condition persists, see your dealer as soon as possible. A Driver
Information Center (DIC) message may
display.
The light flashes when the TCS and/or the
StabiliTrak/ESC system is actively working.
See
Traction Control/Electronic Stability
Control 0214.
Tire Pressure Light
For vehicles with the Tire Pressure Monitor
System (TPMS), this light comes on briefly
when the engine is started. It provides
information about tire pressures and
the TPMS.
When the Light Is On Steady
This indicates that one or more of the tires
are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display. Stop as
soon as possible, and inflate the tires to the pressure value shown on the Tire and
Loading Information label. See
Tire Pressure
0 293.
When the Light Flashes First and Then Is On
Steady
If the light flashes for about a minute and
then stays on, there may be a problem with
the TPMS. If the problem is not corrected,
the light will come on at every ignition
cycle. See Tire Pressure Monitor Operation
0 295.
Engine Oil Pressure Light
Caution
Lack of proper engine oil maintenance
can damage the engine. Driving with the
engine oil low can also damage the
engine. The repairs would not be covered
by the vehicle warranty. Check the oil
level as soon as possible. Add oil if
required, but if the oil level is within the
operating range and the oil pressure is
still low, have the vehicle serviced.
Always follow the maintenance schedule
for changing engine oil.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
102 Instruments and Controls
Vehicle Information Menu (VEHICLE) Items
Units :Choose between Metric or US when
Units is active. Press
Vto confirm the
setting. This will change the displays on the
DIC to the type of measurements you select.
Speed Warning : This display is used to set
the vehicle speed at which the speed
warning chime sounds and the alert is
displayed. The speed can be set by pressing
Vwhile the speed warning display is
showing.
Remaining Oil Life : Displays an estimate of
the oil's remaining useful life. If REMAINING
OIL LIFE 99% is displayed, that means 99%
of the current oil life remains.
When the remaining oil life is low, the
CHANGE ENGINE OIL SOON message will
appear on the display. The oil should be
changed as soon as possible. See Engine Oil
0 262. In addition to the engine oil life
system monitoring the oil life, additional
maintenance is recommended. See
Maintenance Schedule 0331.
The Oil Life display must be reset after each
oil change. Do not reset the Oil Life display
accidentally at any time other than when the oil has just been changed. It cannot be
reset accurately until the next oil change. To
reset, see
Engine Oil Life System 0264.
Oil Pressure : Oil pressure is displayed in
either kilopascal (kPa) or in pounds per
square inch (psi).
Tire Pressure : Displays a vehicle with the
approximate pressures of all four tires. Tire
pressure is displayed in either
kilopascal (kPa) or in pounds per square
inch (psi). See Tire Pressure Monitor System
0 294 and
Tire Pressure Monitor Operation 0295.
Battery Voltage : Displays the current
battery voltage, if equipped. Battery voltage
changes are normal while driving. See
Charging System Light 093. If there is a
problem with the battery charging system,
the DIC will display a message.
Coolant Temperature : Displays the coolant
temperature in degrees Celsius (°C) or
degrees Fahrenheit (°F).
TC/Stabilitrak : If equipped, press
Vto turn
on or off Traction Control or StabiliTrak/
Electronic Stability Control (ESC). ECO Drive Assist Menu (ECO) Items
Fuel Economy :
The center displays the
approximate instantaneous fuel economy as
a number and bar graph. Displayed above
the bar graph is a running average of fuel
economy for the most recently traveled
selected distance. Displayed below the bar
graph is the best average fuel economy that
has been achieved for the selected distance.
The selected distance is displayed at the top
of the page as “last xxx mi/km.” Press
Vto
select the distance or reset best value.
The display provides information on how
current driving behavior affects the running
average and how well recent driving
compares to the best that has been
achieved for the selected distance.
Economy Trend : Shows history of the
Average Fuel Economy from the last 50 km
(30 mi). Each bar represents about 5 km
(3 mi) of driving. During driving the bars will
shift to always reflect the most recent
distance on the right side. Press and hold
V
to clear the graph or pressVto reset
through the menu.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Instruments and Controls 103
Midlevel DIC
Info Page Options
The info pages on the DIC can be turned on
or off through the Options menu.1. Press
oto access the cluster
applications.
2. Press
worxto scroll to the Options
application.
3. Press
Vto enter the Options menu.
4. Scroll to Info Pages and press
p.
5. Press
worxto move through the list
of possible information displays.
6. Press
Vwhile an item is highlighted to
select or deselect that item. When an
item is selected, a checkmark will appear
next to it.
Info Pages
The following is the list of all possible DIC
info page displays. Some may not be
available for your particular vehicle. Some
items may not be turned on by default but
can be turned on through the Options app.
See “Info Page Options” earlier in this
section. Speed :
Shows the vehicle speed in either
kilometers per hour (km/h) or miles per
hour (mph).
Trip A or Trip B : Shows the current distance
traveled, in either kilometers (km) or
miles (mi), since the trip odometer was last
reset.
This also shows the approximate average
liters per 100 kilometers (L/100 km) or miles
per gallon (mpg). This number is calculated
based on the number of L/100 km (mpg)
recorded since the last time this menu item
was reset. This number reflects only the
approximate average fuel economy that the
vehicle has right now, and will change as
driving conditions change.
Press and hold
Vwhile this display is active
to reset the trip odometer and the average
fuel economy. Trip A and Trip B can also be
reset by pressing
pand choosing reset.
Fuel Information or Fuel Range : Shows the
approximate distance the vehicle can be
driven without refueling. LOW will be
displayed when the vehicle is low on fuel.
The fuel range estimate is based on an
average of the vehicle's fuel economy over
recent driving history and the amount of
fuel remaining in the fuel tank. Oil Life :
Shows an estimate of the oil's
remaining useful life. If REMAINING OIL LIFE
99% is displayed, that means 99% of the
current oil life remains.
When the remaining oil life is low, the
CHANGE ENGINE OIL SOON message will
appear on the display. The oil should be
changed as soon as possible. See Engine Oil
0 262. In addition to the engine oil life
system monitoring the oil life, additional
maintenance is recommended. See
Maintenance Schedule 0331.
The Oil Life display must be reset after each
oil change. It will not reset itself. Do not to
reset the Oil Life display at any time other
than when the oil has just been changed.
It cannot be reset accurately until the next
oil change. To reset, see Engine Oil Life
System 0264.
Tire Pressure : Shows the approximate
pressures of all four tires. Tire pressure is
displayed in either kilopascal (kPa) or in
pounds per square inch (psi). If the pressure
is low, the value for that tire is shown in
amber. See Tire Pressure Monitor System
0 294 and
Tire Pressure Monitor Operation 0295.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
106 Instruments and Controls
PressVwhile this display is active to
toggle Speed Limit sign on or off.
Trip 1 or Trip 2 : Shows the current distance
traveled, in either kilometers (km) or
miles (mi), since the trip odometer was last
reset.
If equipped, shows the average fuel
economy since the last reset. This number
reflects only the approximate average fuel
economy that the vehicle has right now,
and will change as driving conditions
change. The average fuel economy can be
displayed as mpg, km/L, or L/100km where
applicable.
If equipped, shows the average speed since
the last reset. This number reflects only the
approximate average speed that the vehicle
has, and will change as driving conditions
change. Average speed can be displayed
as mph or km/h where applicable.
Press
Vwhile this display is active to show
a confirmation window to reset all values to
zero. Use
oorpto select yes or no and
press
V.
Fuel Information or Fuel Range : Shows the
approximate distance the vehicle can be
driven without refueling. LOW will be displayed when the vehicle is low on fuel.
The fuel range estimate is based on an
average of the vehicle's fuel economy over
recent driving history and the amount of
fuel remaining in the fuel tank. If equipped,
may also show the instantaneous fuel
economy.
Oil Life :
Shows an estimate of the oil's
remaining useful life. If REMAINING OIL LIFE
99% is displayed, that means 99% of the
current oil life remains.
When the remaining oil life is low, the
CHANGE ENGINE OIL SOON message will
appear on the display. The oil should be
changed as soon as possible. See Engine Oil
0 262. In addition to the engine oil life
system monitoring the oil life, additional
maintenance is recommended in the
Maintenance Schedule. See Maintenance
Schedule 0331.
The Oil Life display must be reset after each
oil change. It will not reset itself. Do not
reset the Oil Life display at any time other
than when the oil has just been changed.
It cannot be reset accurately until the next
oil change. To reset, see Engine Oil Life
System 0264. Tire Pressure :
Shows the approximate
pressures of all four tires. Tire pressure is
displayed in either kilopascal (kPa) or in
pounds per square inch (psi). If the
pressure is low, the value for that tire is
shown in amber. See Tire Pressure Monitor
System 0294 and
Tire Pressure Monitor Operation 0295.
Air Filter Life : Shows an estimate of the
engine air filter’s remaining useful life and
the state of the system. Engine Air Filter Life
95% means 95% of the current air filter life
remains. Messages will display based on the
engine air filter life and the state of the
system. When the REPLACE AT NEXT OIL
CHANGE message displays, the engine air
filter should be replaced at the time of the
next oil change. When the REPLACE SOON
message displays, the engine air filter
should be replaced at the earliest
convenience.
The Air Filter Life display must be reset after
the engine air filter replacement. To reset,
see Engine Air Filter Life System 0265.
Fuel Economy : The center displays the
approximate instantaneous fuel economy as
a number and bar graph. Displayed above
the bar graph is a running average of fuel
economy for the most recently traveled

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
178 Climate Controls
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . . . . . . . . . . . 178
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Maintenance
Passenger Compartment Air Filter . . . . . 182
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Climate Control Systems
With this system the heating, cooling, and ventilation in the vehicle can be controlled.
1. Fan Control
2. A/C (Air Conditioning)
3. Air Delivery Mode Controls
4. Defrost
5. TEMP (Temperature Control)
6. Rear Window Defogger
7. Air Recirculation
9:Turn clockwise or counterclockwise to
increase or decrease the fan speed or turn
the fan off. TEMP :
Turn the knob clockwise or
counterclockwise to increase or decrease the
temperature.
Air Delivery Mode Control : Press
Y,\,
[, or-to change the direction of the
airflow. An indicator light comes on in the
selected mode button.
Y: Air is directed to the instrument panel
outlets.
\: Air is divided between the instrument
panel and floor outlets.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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182 Climate Controls
Caution
Using a razor blade or sharp object to
clear the inside rear window can damage
the rear window defogger. Repairs would
not be covered by the vehicle warranty.
Do not clear the inside rear window with
sharp objects.
Heated Mirror : If equipped with heated
outside mirrors, the mirrors heat to help
clear fog or frost from the surface of the
mirror when the rear window defog button
is pressed. See Heated Mirrors 025.
Sensor
The solar sensor, on top of the instrument
panel near the windshield, monitors the
solar heat.
The climate control system uses the sensor
information to adjust the temperature, fan
speed, recirculation, and air delivery mode
for best comfort. The automatic recirculation
mode sensitivity can be adjusted. See “Air
Quality Sensor” underVehicle
Personalization 0108.
Do not cover the sensor; otherwise the
automatic climate control system may not
work properly.
Air Vents
Use the louvers located on the air vents to
change the direction of the airflow.
To open or close off the airflow:
.On the center air vents, move the slider
knobs up or down.
.On the outer and rear air vents, move the
slider knobs right or left.
Operation Tips
.Clear away any ice, snow, or leaves from
air inlets at the base of the windshield
that could block the flow of air into the
vehicle.
.Clear snow off the hood to improve
visibility and help decrease moisture
drawn into the vehicle, which may
improve long term system performance.
.Keep the path under the front seats clear
of objects to help circulate the air inside
of the vehicle more effectively.
.Use of non-GM approved hood deflectors
can adversely affect the performance of
the system. Check with your dealer
before adding equipment to the outside
of the vehicle.
.Do not attach any devices to the air vent
slats. This restricts airflow and may cause
damage to the air vents.
Maintenance
Passenger Compartment Air Filter
The filter removes dust, pollen, and other
airborne irritants from outside air that is
pulled into the vehicle.
The filter should be replaced as part of
routine scheduled maintenance. See
Maintenance Schedule 0331. To find out
what type of filter to use, see Maintenance
Replacement Parts 0340.
1. Open the glove box.

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.