change wheel GMC TERRAIN 2021 Owner's Guide

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 223
ACC can reduce the need for you to
frequently brake and accelerate, especially
when used on expressways, freeways, and
interstate highways. When used on other
roads, you may need to take over the
control of braking or acceleration more
often.
{Warning
ACC has limited braking ability and may
not have time to slow the vehicle down
enough to avoid a collision with another
vehicle you are following. This can occur
when vehicles suddenly slow or stop
ahead, or enter your lane. Also see
“Alerting the Driver”later in this section.
Complete attention is always required
while driving and you should be ready to
take action and apply the brakes. See
Defensive Driving 0187.
{Warning
ACC will not detect or brake for children,
pedestrians, animals, or other objects.
Do not use ACC when:
.On winding and hilly roads or when
the camera sensor is blocked by snow,
ice, or dirt. The system may not
detect a vehicle ahead. Keep the
windshield and headlamps clean.
.When visibility is poor due to rain,
snow, fog, dirt, insect residue, or dust;
when other foreign objects obscure
the camera’s view; or when the
vehicle in front or oncoming traffic
causes additional environmental
obstructions, such as road spray. ACC
performance is limited under these
conditions.
.On slippery roads where fast changes
in tire traction can cause excessive
wheel slip
.With extremely heavy cargo loaded in
the cargo area or rear seat
.When towing a trailer
J:Press to turn the system on or off. The
indicator turns white on the instrument
cluster when ACC is turned on.
RES+ : Press briefly to resume the previous
set speed or to increase vehicle speed if ACC
is already activated. To increase speed by
about 1 km/h (1 mph), press RES+ briefly. To
increase speed to the next 5 km/h (5 mph)
mark on the speedometer, hold RES+.
SET– :Press briefly to set the speed and
activate ACC or to decrease vehicle speed if
ACC is already activated. To decrease speed
by about 1 km/h (1 mph), press SET– briefly.
To decrease speed to the next 5 km/h
(5 mph) mark on the speedometer,
hold SET–.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
226 Driving and Operating
.Press and hold SET–until the desired
lower speed is reached, then release it.
.To decrease the vehicle speed in smaller
increments, press SET− briefly. For each
press, the vehicle goes about 1 km/h
(1 mph) slower.
.To decrease the vehicle speed in larger
increments, hold SET−. While holding
SET−, the vehicle speed decreases to the
next 5 km/h (5 mph) step, then continues
to decrease by 5 km/h (5 mph) at a time.
The set speed can also be decreased while
the vehicle is stopped.
.If stopped with the brake applied, press
or hold SET− until the desired set speed is
displayed.
Selecting the Follow Distance Gap
When a slower moving vehicle is detected
ahead within the selected following gap,
ACC will adjust the vehicle's speed and
attempt to maintain the follow distance gap
selected.
Press
[on the steering wheel to adjust
the following gap. Each press cycles the gap
button through three settings: Far, Medium,
or Near. When pressed, the current gap setting
displays briefly on the instrument cluster.
The gap setting will be maintained until it is
changed.
Since each gap setting corresponds to a
following time (Far, Medium, or Near), the
following distance will vary based on vehicle
speed. The faster the vehicle speed, the
further back your vehicle will follow a
vehicle detected ahead. Consider traffic and
weather conditions when selecting the
following gap. The range of selectable gaps
may not be appropriate for all drivers and
driving conditions.
Changing the gap setting automatically
changes the alert timing sensitivity (Far,
Medium, or Near) for the Forward Collision
Alert (FCA) feature. See
Forward Collision
Alert (FCA) System 0237.
Alerting the Driver
If ACC is engaged, driver action may be
required when ACC cannot apply sufficient
braking because of approaching a vehicle
too rapidly.
When this condition occurs, the collision
alert symbol will flash on the windshield.
Either eight beeps will sound from the front,
or both sides of the Safety Alert Seat (if
equipped) will pulse five times. See
“Collision/Detection Systems” underVehicle
Personalization 0108.
See Defensive Driving 0187.
Approaching and Following a Vehicle
The vehicle ahead indicator is in the
instrument cluster. It only displays when a
vehicle is detected in your vehicle’s path
moving in the same direction. If this symbol
is not displaying, ACC will not respond to or
brake for vehicles ahead.
ACC automatically slows the vehicle down
and adjusts vehicle speed to follow a
detected vehicle ahead at the selected

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 237
After completely passing a large enough
space, an audible beep occurs and a red stop
symbol is displayed.
If the vehicle is in R (Reverse), but does not
steer into the expected space, this may be
because the system is maneuvering the
vehicle into a previously detected space. The
APA system does not need service.
APA will instruct the vehicle to stop once a
large enough space is found. Follow the
displayed instructions. When instructed todrive in reverse, shift to R (Reverse) to
engage automatic steering. The steering
wheel will briefly vibrate as a reminder to
remove hands from the steering wheel.
Check surroundings and continue braking or
accelerating as needed, and be prepared to
stop to avoid vehicles, pedestrians,
or objects.
If the vehicle exceeds 10 km/h (6 mph), APA
is automatically disengaged and automatic
steering will turn off. A progress arrow
displays the status of the parking maneuver.
Depending on the space size, additional
maneuvers may be required, and there will
be additional instructions. When changing
gears, allow the automatic steering to
complete before continuing the parking
maneuver. Upon successful completion of a
maneuver, APA will beep and display a
PARKING COMPLETE message. Place the
vehicle in P (Park).
APA may automatically disengage if:
.The steering wheel is used by the driver.
.The maximum allowed speed is exceeded.
.There is a failure with the APA system.
.Electronic stability control or antilock
brakes are activated.
.A high priority vehicle message is
displayed in the Driver Information
Center (DIC).
To cancel APA, press
Oagain.
When the System Does Not Seem to Work
Properly
The APA system may require a short period
of driving along curves to calibrate.
Assistance Systems for Driving
If equipped, when driving the vehicle in a
forward gear, Forward Collision Alert (FCA),
Lane Keep Assist (LKA), Side Blind Zone Alert
(SBZA), Lane Change Alert (LCA), Automatic
Emergency Braking (AEB), and/or the Front
Pedestrian Braking (FPB) System can help to
avoid a crash or reduce crash damage.
Forward Collision Alert (FCA)
System
If equipped, the FCA system may help to
avoid or reduce the harm caused by
front-end crashes. When approaching a
vehicle ahead too quickly, FCA provides a
red flashing alert on the windshield and
rapidly beeps or pulses the driver seat. FCA
also lights an amber visual alert if following
another vehicle much too closely.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Driving and Operating 239
Tailgating Alert
The vehicle ahead indicator will display
amber when you are following a vehicle
ahead much too closely.
Selecting the Alert Timing
The Collision Alert control is on the steering
wheel. Press
[to set the FCA timing to
Far, Medium, or Near, or on some vehicles,
Off. The first button press shows the current
setting on the DIC. Additional button presses
will change this setting. The chosen setting
will remain until it is changed and will affect
the timing of both the Collision Alert and
the Tailgating Alert features. The timing of
both alerts will vary based on vehicle speed.
The faster the vehicle speed, the farther
away the alert will occur. Consider traffic
and weather conditions when selecting the
alert timing. The range of selectable alert
timings may not be appropriate for all
drivers and driving conditions.
Following Distance Indicator
The following distance to a moving vehicle
ahead in your path is indicated in following
time in seconds on the Driver Information
Center (DIC). See Driver Information Center
(DIC) (Base and Midlevel) 0100 or
Driver Information Center (DIC) (Uplevel)
0 105. The minimum following time is
0.5 seconds away. If there is no vehicle
detected ahead, or the vehicle ahead is out
of sensor range, dashes will be displayed.
Unnecessary Alerts
FCA may provide unnecessary alerts for
turning vehicles, vehicles in other lanes,
objects that are not vehicles, or shadows.
These alerts are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to operate
properly, this may correct the issue:
.Clean the outside of the windshield in
front of the rearview mirror.
.Clean the entire front of the vehicle.
.Clean the headlamps.
Automatic Emergency
Braking (AEB)
If the vehicle has Forward Collision Alert
(FCA), it also has AEB, which includes
Intelligent Brake Assist (IBA). When the
system detects a vehicle ahead in your path
that is traveling in the same direction that
you may be about to crash into, it can
provide a boost to braking or automatically
brake the vehicle. This can help avoid or
lessen the severity of crashes when driving
in a forward gear. Depending on the
situation, the vehicle may automatically
brake moderately or hard. This automatic
emergency braking can only occur if a
vehicle is detected. This is shown by the FCA
vehicle ahead indicator being lit. See
Forward Collision Alert (FCA) System 0237.
The system works when driving in a forward
gear between 8 km/h (5 mph) and 80 km/h
(50 mph). It can detect vehicles up to
approximately 60 m (197 ft).
{Warning
AEB is an emergency crash preparation
feature and is not designed to avoid
crashes. Do not rely on AEB to brake the (Continued)

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Driving and Operating 245
Warning (Continued)
Always keep your attention on the road
and maintain proper vehicle position
within the lane, or vehicle damage,
injury, or death could occur. Always keep
the windshield, headlamps, and camera
sensors clean and in good repair. Do not
use LKA in bad weather conditions or on
roads with unclear lane markings, such as
construction zones.
{Warning
Using LKA while towing a trailer or on
slippery roads could cause loss of control
of the vehicle and a crash. Turn the
system off.
How the System Works
LKA uses a camera sensor installed on the
windshield ahead of the rearview mirror to
detect lane markings. It may provide brief
steering assist if it detects an unintended
lane departure. It may further provide an
audible alert or the driver seat may pulse
indicating that a lane marking has been
crossed.To turn LKA on and off, press
Aon the
center console. If equipped, the indicator
light on the button comes on when LKA is
on and turns off when LKA is disabled.
When on,
Ais white, if equipped,
indicating that the system is not ready to
assist.
Ais green if LKA is ready to
assist. LKA may assist by gently turning the
steering wheel if the vehicle approaches a
detected lane marking.
Ais amber when
assisting. It may also provide a Lane
Departure Warning (LDW) alert by flashing
Aamber if the vehicle crosses a
detected lane marking. Additionally, there
may be three beeps, or the driver seat may
pulse three times, on the right or left,
depending on the lane departure direction.
Take Steering
The LKA system does not continuously steer
the vehicle. If LKA does not detect active
driver steering, an alert and chime may be
provided. Steer the vehicle to dismiss. LKA
may become temporarily unavailable after
repeated take steering alerts.
When the System Does Not Seem to
Work Properly
The system performance may be
affected by:
.Close vehicles ahead.
.Sudden lighting changes, such as when
driving through tunnels.
.Banked roads.
.Roads with poor lane markings, such as
two-lane roads.
If the LKA system is not functioning
properly when lane markings are clearly
visible, cleaning the windshield may help.
A camera blocked message may display if
the camera is blocked. Some driver
assistance systems may have reduced
performance or not work at all. An LKA or
LDW unavailable message may display if the
systems are temporarily unavailable. This
message could be due to a blocked camera.
The LKA system does not need service. Clean
the outside of the windshield behind the
rearview mirror.
LKA assistance and/or LDW alerts may occur
due to tar marks, shadows, cracks in the
road, temporary or construction lane
markings, or other road imperfections. This

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Vehicle Care 265
4. If the display changes to 100%, thesystem is reset.
If the CHANGE ENGINE OIL SOON message
comes back on when the vehicle is started,
the engine oil life system has not reset.
Repeat the procedure.
Automatic Transmission Fluid
It is not necessary to check the transmission
fluid level. A transmission fluid leak is the
only reason for fluid loss. If a leak occurs,
take the vehicle to your dealer and have it
repaired as soon as possible.
Change the fluid at the intervals listed in
Maintenance Schedule 0331, and be sure to
use the transmission fluid listed in
Recommended Fluids and Lubricants 0339.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty. Always
use the correct automatic transmission
fluid. See Recommended Fluids and
Lubricants 0339. There is a special procedure for checking and
changing the transmission fluid. Because this
procedure is difficult, this should be done by
your dealer.
Engine Air Filter Life System
If equipped, this feature provides the engine
air filter’s remaining life and best timing for
a change. The timing to change an engine
air filter depends on driving and
environmental conditions.
When to Change the Engine Air Filter
When the Driver Information Center (DIC)
displays a message to replace the engine air
filter at the next oil change, follow this
timing.
When the DIC displays a message to replace
the engine air filter soon, replace the engine
air filter at the earliest convenience.
The system must be reset after the engine
air filter is changed.
If the DIC displays a message to check the
engine air filter system, see your dealer.
How to Reset the Engine Air Filter Life
System
To reset:
1. Place the vehicle in P (Park).
2. Display the Air Filter Life on the DIC. See Driver Information Center (DIC) (Base and
Midlevel) 0100 or
Driver Information Center (DIC) (Uplevel)
0 105.
3. Press
pon the steering wheel to move
to the Reset/Disable display area. Select
Reset then press
V.
4. Press
Vto confirm the reset.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the engine
compartment on the passenger side of the
vehicle. See Engine Compartment Overview
0 261.
When to Inspect the Engine Air Cleaner/
Filter
If the vehicle is not equipped with the
engine air filter life system, see
Maintenance Schedule 0331.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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272 Vehicle Care
pads are needed. The sound can come and
go or can be heard all the time when the
vehicle is moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound means
that soon the brakes will not work well.
That could lead to a crash. When the
brake wear warning sound is heard, have
the vehicle serviced.
Caution
Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates can
cause a brake squeal when the brakes are
first applied or lightly applied. This does not
mean something is wrong with the brakes.
Properly torqued wheel nuts are necessary
to help prevent brake pulsation. When tires
are rotated, inspect brake pads for wear and
evenly tighten wheel nuts in the proper
sequence to torque specifications. See
Capacities and Specifications 0343.
Brake pads should be replaced as
complete sets.
Brake Pedal Travel
See your dealer if the brake pedal does not
return to normal height, or if there is a
rapid increase in pedal travel. This could be
a sign that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts with
new, approved replacement parts. If this is
not done, the brakes may not work
properly. The braking performance expected
can change in many other ways if the
wrong replacement brake parts are installed
or if parts are improperly installed.
Brake Fluid
The brake master cylinder reservoir is filled
with GM approved DOT 3 brake fluid as
indicated on the reservoir cap. See Engine
Compartment Overview 0261 for the
location of the reservoir. Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum marks
on the brake fluid reservoir.
There are only two reasons why the brake
fluid level in the reservoir may go down:
.Normal brake lining wear. When new
linings are installed, the fluid level goes
back up.
.A fluid leak in the brake hydraulic system.
Have the brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid reservoir cap
and the area around the cap before
removing it.
Do not top off the brake fluid. Adding fluid
does not correct a leak. If fluid is added
when the linings are worn, there will be too
much fluid when new brake linings are
installed. Add or remove fluid, as necessary,
only when work is done on the brake
hydraulic system.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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288 Vehicle Care
Consider installing winter tires on the
vehicle if frequent driving on snow or
ice-covered roads is expected. All-season tires
provide adequate performance for most
winter driving conditions, but they may not
offer the same level of traction or
performance as winter tires on snow or
ice-covered roads. SeeWinter Tires0288.
Winter Tires
This vehicle was not originally equipped
with winter tires. Winter tires are designed
for increased traction on snow and
ice-covered roads. Consider installing winter
tires on the vehicle if frequent driving on ice
or snow covered roads is expected. See your
dealer for details regarding winter tire
availability and proper tire selection. Also,
see Buying New Tires 0300.
With winter tires, there may be decreased
dry road traction, increased road noise, and
shorter tread life. After changing to winter
tires, be alert for changes in vehicle
handling and braking.
If using winter tires:
.Use tires of the same brand and tread
type on all four wheel positions.
.Use only radial ply tires of the same size,
load range, and speed rating as the
original equipment tires.
Winter tires with the same speed rating as
the original equipment tires may not be
available for H, V, W, Y, and ZR speed rated
tires. If winter tires with a lower speed
rating are chosen, never exceed the tire's
maximum speed capability.
Summer Tires
This vehicle may come with high
performance summer tires. These tires have
a special tread and compound that are
optimized for maximum dry and wet road
performance. This special tread and
compound will have decreased performance
in cold climates, and on ice and snow. It is
recommended that winter tires be installed
on the vehicle if frequent driving at
temperatures below approximately 5 °C
(40 °F) or on ice or snow covered roads is
expected. See Winter Tires0288.
Caution
High performance summer tires have
rubber compounds that lose flexibility
and may develop surface cracks in the
(Continued)
Caution (Continued)
tread area at temperatures below −7 °C
(20 °F). Always store high performance
summer tires indoors and at
temperatures above −7 °C (20 °F) when
not in use. If the tires have been
subjected to −7 °C (20 °F) or less, let them
warm up in a heated space to at least
5 °C (40 °F) for 24 hours or more before
being installed or driving a vehicle on
which they are installed. Do not apply
heat or blow heated air directly on the
tires. Always inspect tires before use. See
Tire Inspection 0298.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The examples
show a typical passenger vehicle tire
and a compact spare tire sidewall.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Vehicle Care 299
Check that all wheel nuts are properly
tightened. See“Wheel Nut Torque”
under Capacities and Specifications
0 343, and “Removing the Flat Tire and
Installing the Spare Tire” underTire
Changing 0310.
{Warning
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
cause wheel nuts to become loose
over time. The wheel could come off
and cause a crash. When changing a
wheel, remove any rust or dirt from
places where the wheel attaches to
the vehicle. In an emergency, a cloth
or paper towel can be used; however,
use a scraper or wire brush later to
remove all rust or dirt.
Lightly coat the inner diameter of the
wheel hub opening with wheel bearing
grease after a wheel change or tire
rotation to prevent corrosion or rust
buildup.
{Warning
Do not apply grease to the wheel
mounting surface, wheel conical
seats, or the wheel nuts or bolts.
Grease applied to these areas could
cause a wheel to become loose or
come off, resulting in a crash.
When It Is Time for New Tires
Factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road
conditions affect the wear rate of the tires.
Treadwear indicators are one way to tell
when it is time for new tires. Treadwear
indicators appear when the tires have only 1.6 mm (1/16 in) or less of tread remaining.
See
Tire Inspection 0298 and
Tire Rotation 0298 for additional
information.
The rubber in tires ages over time. This also
applies to the spare tire, if the vehicle has
one, even if it is never used. Multiple factors
including temperatures, loading conditions,
and inflation pressure maintenance affect
how fast aging takes place. GM recommends
that tires, including the spare if equipped,
be replaced after six years, regardless of
tread wear. To identify the age of a tire, use
the tire manufacture date, which is the last
four digits of the DOT Tire Identification
Number (TIN) molded into one side of the
tire sidewall. The last four digits of the TIN
indicate the tire manufactured date. The
first two digits represent the week and the
last two digits, the year. For example, the
third week of the year 2020 would have a
4-digit DOT date of 0320. Week 01 is the
first full week (Sunday through Saturday) of
each year.
Vehicle Storage
Tires age when stored normally mounted on
a parked vehicle. Park a vehicle that will be
stored for at least a month in a cool, dry,
clean area away from direct sunlight to slow

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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304 Vehicle Care
A rear blowout, particularly on a curve, acts
much like a skid and may require the same
correction as used in a skid. Stop pressing
the accelerator pedal and steer to straighten
the vehicle. It may be very bumpy and
noisy. Gently brake to a stop, well off the
road, if possible.
{Warning
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been driven
on while severely underinflated or flat
may cause a blowout and a serious crash.
Never attempt to re-inflate a tire that has
been driven on while severely
underinflated or flat. Have your dealer or
an authorized tire service center repair or
replace the flat tire as soon as possible.
{Warning
Lifting a vehicle and getting under it to
do maintenance or repairs is dangerous
without the appropriate safety equipment
and training. If a jack is provided with
the vehicle, it is designed only for(Continued)
Warning (Continued)
changing a flat tire. If it is used for
anything else, you or others could be
badly injured or killed if the vehicle slips
off the jack. If a jack is provided with the
vehicle, only use it for changing a
flat tire.
If a tire goes flat, avoid further tire and
wheel damage by driving slowly to a level
place, well off the road, if possible. Turn on
the hazard warning flashers. See Hazard
Warning Flashers 0119.
{Warning
Changing a tire can be dangerous. The
vehicle can slip off the jack and roll over
or fall causing injury or death. Find a
level place to change the tire. To help
prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put an automatic transmission in P (Park) or a manual transmission in
1 (First) or R (Reverse).
3. Turn off the engine and do not restart while the vehicle is raised.
(Continued)
Warning (Continued)
4. Do not allow passengers to remainin the vehicle.
5. Place wheel blocks, if equipped, on both sides of the tire at the opposite
corner of the tire being changed.
This vehicle may come with a jack and spare
tire or a tire sealant and compressor kit. To
use the jacking equipment to change a spare
tire safely, follow the instructions below.
Then see Tire Changing 0310. To use the
tire sealant and compressor kit, see Tire
Sealant and Compressor Kit 0305.
When the vehicle has a flat tire (2), use the
following example as a guide to assist you
in the placement of wheel blocks (1),
if equipped.