brakes 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 225
The ACC indicator displays on the
instrument cluster. When ACC is turned on,
the indicator will be lit white. When ACC is
active, the indicator will turn green.
Be mindful of speed limits, surrounding
traffic speeds, and weather conditions when
selecting the set speed.
Resuming a Set Speed
If the ACC is set at a desired speed and then
the brakes are applied, ACC is disengaged
without erasing the set speed from memory.
To begin using ACC again, press RES+ up
briefly.
.If the vehicle is moving more than 5 km/h
(3 mph), it returns to the previous set
speed.
.If the vehicle is stopped with the brake
pedal applied, press RES+ and release the
brake pedal. ACC will hold the vehicle
until RES+ or the accelerator pedal is
pressed.
A green ACC indicator and the set speed
display on the instrument cluster. The
vehicle ahead indicator may be flashing if a
vehicle ahead was present and moved. See
“Approaching and Following a Vehicle” later
in this section. Once ACC has resumed, the vehicle speed
will increase to the set speed under the
following conditions:
.There is no vehicle ahead.
.The vehicle ahead is beyond the selected
following gap.
.The vehicle speed is not being limited
because of a sharp turn.
Increasing Speed While ACC Is at a Set Speed
If ACC is already activated, do one of the
following:
.Use the accelerator pedal to get to the
higher speed. Briefly press and release
SET– and release the accelerator pedal.
The vehicle will now cruise at the higher
speed.
When the accelerator pedal is pressed,
ACC will not brake because it is
overridden. While overridden, the ACC
indicator will turn blue on the instrument
cluster.
.Press and hold RES+ until the desired set
speed is displayed, then release it.
.To increase vehicle speed in smaller
increments, press RES+ briefly. For each
press, the vehicle goes about 1 km/h
(1 mph) faster.
.To increase vehicle speed in larger
increments, hold RES+. While holding RES
+, the vehicle speed increases to the next
5 km/h (5 mph) step, then continues to
increase by 5 km/h (5 mph) at a time.
The set speed can also be increased while
the vehicle is stopped.
.If stopped with the brake applied, press
RES+ until the desired set speed is
displayed.
.If ACC is holding the vehicle at a stop and
there is another vehicle directly ahead,
pressing RES+ will increase the set speed.
.Pressing RES+ when there is no longer a
vehicle ahead or the vehicle ahead is
pulling away and the brake is not applied
will cause ACC to resume.
When it is determined that there is no
vehicle ahead or the vehicle ahead is beyond
the selected following gap, then the vehicle
speed will increase to the set speed.
Reducing Speed While ACC Is at a Set Speed
If ACC is already activated, do one of the
following:
.Use the brake to get to the desired lower
speed. Release the brake and press SET–.
The vehicle will now cruise at the lower
speed.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Driving and Operating 227
following gap. The vehicle speed increases or
decreases to follow a detected vehicle in
front of your vehicle when that vehicle is
traveling slower than your vehicle set speed.
It may apply limited braking, if necessary.
When braking is active, the brake lamps will
come on. The automatic braking may feel or
sound different than if the brakes were
applied manually. This is normal.
Passing a Vehicle While Using ACC
If the set speed is high enough, and the left
turn signal is used to pass a vehicle ahead
in the selected following gap, ACC may
assist by gradually accelerating the vehicle
prior to the lane change.
{Warning
When using ACC to pass a vehicle or
perform a lane change, the following
distance to the vehicle being passed may
be reduced. ACC may not apply sufficient
acceleration or braking when passing a
vehicle or performing a lane change.
Always be ready to manually accelerate
or brake to complete the pass or lane
change.Stationary or Very Slow-Moving Objects
{Warning
ACC may not detect and react to stopped
or slow-moving vehicles ahead of you. For
example, the system may not brake for a
vehicle it has never detected moving. This
can occur in stop-and-go traffic or when a
vehicle suddenly appears due to a vehicle
ahead changing lanes. Your vehicle may
not stop and could cause a crash. Use
caution when using ACC. Your complete
attention is always required while driving
and you should be ready to take action
and apply the brakes.
Irregular Objects Affecting ACC
ACC may have difficulty detecting the
following objects:
.Vehicles in front of your vehicle that have
a rear aspect that is low, small,
or irregular
.An empty truck or trailer that has no
cargo in the cargo bed
.Vehicles with cargo extending from the
back end
.Non-standard shaped vehicles, such as
vehicle transport, vehicles with a side car
fitted, or horse carriages
.Vehicles that are low to the road surface
.Objects that are close to the front of your
vehicle
.Vehicles on which extremely heavy cargo
is loaded in the cargo area or rear seat
ACC Automatically Disengages
ACC may automatically disengage and the
driver will need to manually apply the
brakes to slow the vehicle if:
.The front camera is blocked or visibility is
reduced.
.The Traction Control System (TCS) or
StabiliTrak/ESC system has activated or
been disabled.
.There is a fault in the system.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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228 Driving and Operating
.A DIC message displays to indicate that
ACC is temporarily unavailable.
The ACC indicator will turn white when ACC
is no longer active.
In some cases, when ACC is temporarily
unavailable, regular cruise control may be
used. See “Switching Between ACC and
Regular Cruise Control” in this section.
Always consider driving conditions before
using either cruise control system.
Notification to Resume ACC
ACC will maintain a follow gap behind a
detected vehicle and slow your vehicle to a
stop behind that vehicle.
If the stopped vehicle ahead has driven
away and ACC has not resumed, the vehicle
ahead indicator will flash as a reminder to
check traffic ahead before proceeding. In
addition, the left and right sides of the
Safety Alert Seat will pulse three times,
or three beeps will sound. See ”Alert Type”
and “Adaptive Cruise Go Notifier” in
“Collision/Detection Systems” underVehicle
Personalization 0108.
When the vehicle ahead drives away, ACC
resumes automatically if the stop was brief.
If necessary, press RES+ or the accelerator
pedal to resume ACC. If stopped for more than two minutes or if the driver door is
opened and the driver seat belt is
unbuckled, the ACC automatically applies the
Electric Parking Brake (EPB) to hold the
vehicle. The EPB status light will turn on.
See
Electric Parking Brake 0212. To release
the EPB, press the accelerator pedal.
A DIC warning message may display
indicating to shift to P (Park) before exiting
the vehicle. See Vehicle Messages 0108.
{Warning
If ACC has stopped the vehicle, and if ACC
is disengaged, turned off, or canceled, the
vehicle will no longer be held at a stop.
The vehicle can move. When ACC is
holding the vehicle at a stop, always be
prepared to manually apply the brakes.
{Warning
Leaving the vehicle without placing it in
P (Park) can be dangerous. Do not leave
the vehicle while it is being held at a
stop by ACC. Always place the vehicle in
P (Park) and turn off the ignition before
leaving the vehicle. ACC Override
If using the accelerator pedal while ACC is
active, the ACC indicator turns blue on the
instrument cluster, to indicate that
automatic braking will not occur. ACC will
resume operation when the accelerator
pedal is not being pressed.
{Warning
The ACC will not automatically apply the
brakes if your foot is resting on the
accelerator pedal. You could crash into a
vehicle ahead of you.
Curves in the Road
{Warning
On curves, ACC may not detect a vehicle
ahead in your lane. You could be startled
if the vehicle accelerates up to the set
speed, especially when following a vehicle
exiting or entering exit ramps. You could
lose control of the vehicle or crash. Do
not use ACC while driving on an entrance
or exit ramp. Always be ready to use the
brakes if necessary.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Driving and Operating 229
{Warning
On curves, ACC may respond to a vehicle
in another lane, or may not have time to
react to a vehicle in your lane. You could
crash into a vehicle ahead of you, or lose
control of your vehicle. Give extra
attention in curves and be ready to use
the brakes if necessary. Select an
appropriate speed while driving in curves.
ACC may operate differently in a sharp
curve. It may reduce the vehicle speed if the
curve is too sharp.
ACC automatically slows the vehicle down
while navigating the curve and may increase
speed out of the curve, but will not exceed
the set speed.
When following a vehicle and entering a
curve, ACC may not detect the vehicle ahead
and accelerate to the set speed. When this
happens, the vehicle ahead indicator will not
appear.
ACC may detect a vehicle that is not in your
lane and apply the brakes.
ACC may occasionally provide an alert and/
or braking that is considered unnecessary.
It could respond to vehicles in different
lanes or stationary objects when entering or
exiting a curve. This is normal operation.
The vehicle does not need service. Other Vehicle Lane Changes
ACC will not detect a vehicle ahead until it
is completely in the lane. The brakes may
need to be manually applied.
Objects Not Directly in Front of Your Vehicle
The detection of objects in front of the
vehicle may not be possible if:
.The vehicle or object ahead is not within
your lane.
.The vehicle ahead is shifted, not centered,
or is shifted to one side of the lane.
Driving in Narrow Lanes
Vehicles in adjacent traffic lanes or roadside
objects may be incorrectly detected when
located along the roadway.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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230 Driving and Operating
Do Not Use ACC on Hills and When Towing a
Trailer
Do not use ACC when driving on steep hills
or when towing a trailer. ACC will not detect
a vehicle in the lane while driving on steep
hills. If the brakes are applied, ACC
disengages.
Disengaging ACC
There are three ways to disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.PressJ.
Erasing Speed Memory
The ACC set speed is erased from memory if
Jis pressed or if the ignition is turned off. Weather Conditions Affecting ACC
If the interior temperature is extremely
high, the instrument cluster may indicate
that ACC is temporarily unavailable. This can
be caused by extreme hot weather
conditions with direct sunlight on the front
camera. ACC will return to normal operation
once the cabin temperature is lower.
Conditions that are associated with low
visibility, such as fog, rain, snow, or road
spray, may limit ACC performance. Water
droplets from rain or snow that remain on
the windshield may also limit ACC’s ability
to detect objects.
{Warning
Camera visibility may be limited and the
ACC system may not work properly if the
windshield is not clear. Do not use ACC if
moisture is present on the inside of the
windshield or the windshield washer is
used in cold weather. Turn on the front
defroster and make sure the windshield is
clear before using ACC. Before driving,
check that the windshield wipers are in
good condition and replace them if worn. Lighting Conditions Affecting ACC
The ACC front camera can be affected by
poor lighting conditions, and ACC may have
limited performance when:
.There are changes in brightness, such as
entering and exiting tunnels, bridges, and
overpasses.
.Low sun angles cause the camera to not
detect objects, or it is more difficult to
detect objects in the same traffic lane.
.Lighting is poor in the evening or early
morning
.There are multiple changes in brightness
or shadows along the vehicle roadway.
.In a tunnel without the headlamps on,
or in a tunnel when there is a vehicle in
front that does not have its taillamps on.
.Subjected to strong light from opposing
lane traffic in the front of the vehicle,
such as high-beam headlamps from
oncoming traffic.
Accessory Installations and Vehicle
Modifications
Do not install or place any object around
the front camera windshield area that would
obstruct the front camera view.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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Driving and Operating 231
Do not install objects on top of the vehicle
that overhang and obstruct the front
camera, such as a canoe, kayak, or other
items that can be transported on a roof rack
system. SeeRoof Rack System 076.
Do not modify the hood, headlamps, or fog
lamps, as this may limit the camera’s ability
to detect an object.
Cleaning the Sensing System
The camera sensor on the windshield behind
the rearview mirror can become blocked by
snow, ice, dirt, mud, or debris. This area
needs to be cleaned for ACC to operate
properly.
The vehicle headlamps may need to be
cleaned due to dirt, snow, or ice. Objects
that are not illuminated correctly may be
difficult to detect.
If ACC will not operate, regular cruise control
may be available. See “Switching Between
ACC and Regular Cruise Control” in this
section. Always consider driving conditions
before using either cruise control system.
For cleaning instructions, see “Washing the
Vehicle” underExterior Care 0322.Driver Assistance Systems
This vehicle may have features that work
together to help avoid crashes or reduce
crash damage while driving, backing, and
parking. Read this entire section before
using these systems.
{Warning
Do not rely on the Driver Assistance
Systems. These systems do not replace
the need for paying attention and driving
safely. You may not hear or feel alerts or
warnings provided by these systems.
Failure to use proper care when driving
may result in injury, death, or vehicle
damage. See Defensive Driving 0187.
Under many conditions, these systems
will not:
.Detect children, pedestrians, bicyclists,
or animals.
.Detect vehicles or objects outside the
area monitored by the system.
.Work at all driving speeds.
.Warn you or provide you with enough
time to avoid a crash. (Continued)
Warning (Continued)
.Work under poor visibility or bad
weather conditions.
.Work if the detection sensor is not
cleaned or is covered by ice, snow,
mud, or dirt.
.Work if the detection sensor is
covered up, such as with a sticker,
magnet, or metal plate.
.Work if the area surrounding the
detection sensor is damaged or not
properly repaired.
Complete attention is always required
while driving, and you should be ready to
take action and apply the brakes and/or
steer the vehicle to avoid crashes.
Audible or Safety Alert Seat
Some driver assistance features alert the
driver of obstacles by beeping. To change
the volume of the warning chime, see
“Comfort and Convenience” underVehicle
Personalization 0108.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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236 Driving and Operating
right. This system detects objects coming
from up to 20 m (65 ft) from the left or
right side of the vehicle. When an object is
detected, either three beeps sound from the
left or right or three Safety Alert Seat pulses
occur on the left or right side, depending on
the direction of the detected vehicle.
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.
Turning the Features On or Off
TheXbutton on the center console is
used to turn on or off the Front and Rear
Park Assist and the Rear Cross Traffic Alert
(RCTA). The indicator light in the button
comes on when the features are on and
turns off when the features have been
disabled.
Turn off Park Assist and RCTA when towing
a trailer.
RCTA can be turned off through “Collision/
Detection Systems” underVehicle
Personalization 0108.
Automatic Parking Assist (APA)
If equipped, APA searches for and steers the
vehicle into parallel and perpendicular
parking spots. When using APA, you must
still shift gears, and control the brakes and
accelerator. A display and audible beeps help
to guide parking maneuvers.
{Warning
APA does not apply the brakes. APA may
not detect objects in the parking space,
objects that are soft or narrow, objects
high off the ground such as flatbed
trucks, or objects below ground level such
as large potholes. Always verify that the
parking space is appropriate for parking a
vehicle. APA does not respond to changes
in the parking space, such as movement
of an adjacent vehicle, or a person or
object entering the parking space. APA
does not detect or avoid traffic that is
behind or alongside of the vehicle.
Always be prepared to stop the vehicle
during the parking maneuver. Press
Oon the center console to enable
the system to search for a parking space
that is large enough and within 1.5 m (5 ft)
of the vehicle. The vehicle speed must be
below 30 km/h (18 mph). The system cannot:
.Detect whether it is a legal parking space.
.Park exactly lined up with the vehicle
next to it if the spot is approached at an
angle or if the parking space is angled.
.Park exactly centered in a spot that is
marked too large.
.Always detect short curbs.
When enabled, APA searches for parallel
parking spaces to the right of the vehicle. To
search for a parking space to the left, turn
on the left turn signal or, if available,
change the side selection in the
infotainment display. To switch the parking
mode between parallel and perpendicular,
press and hold
Oduring the search process
or, if available, change the parking mode in
the infotainment display.

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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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238 Driving and Operating
FCA detects vehicles within a distance of
approximately 60 m (197 ft) and operates at
speeds above 8 km/h (5 mph).
{Warning
FCA is a warning system and does not
apply the brakes. When approaching a
slower-moving or stopped vehicle ahead
too rapidly, or when following a vehicle
too closely, FCA may not provide a
warning with enough time to help avoid
a crash. It also may not provide any
warning at all. FCA does not warn of
pedestrians, animals, signs, guardrails,
bridges, construction barrels, or other
objects. Be ready to take action and
apply the brakes. SeeDefensive Driving
0 187.
FCA can be disabled with the FCA steering
wheel control, or if equipped, through
vehicle personalization. See “Collision/
Detection Systems” underVehicle
Personalization 0108.
Detecting the Vehicle Ahead
FCA warnings will not occur unless the FCA
system detects a vehicle ahead. When a
vehicle is detected, the vehicle ahead
indicator will display green. Vehicles may
not be detected on curves, highway exit
ramps, or hills, due to poor visibility; or if a
vehicle ahead is partially blocked by
pedestrians or other objects. FCA will not
detect another vehicle ahead until it is
completely in the driving lane.
{Warning
FCA does not provide a warning to help
avoid a crash, unless it detects a vehicle.
FCA may not detect a vehicle ahead if
the FCA sensor is blocked by dirt, snow,
or ice, or if the windshield is damaged.
It may also not detect a vehicle on
winding or hilly roads, or in conditions
that can limit visibility such as fog, rain,
(Continued)
Warning (Continued)
or snow, or if the headlamps or
windshield are not cleaned or in proper
condition. Keep the windshield,
headlamps, and FCA sensors clean and in
good repair.
Collision Alert
When your vehicle approaches another
detected vehicle too rapidly, the red FCA
display will flash on the windshield. Also,
eight rapid high-pitched beeps will sound
from the front, or both sides of the Safety
Alert Seat will pulse five times. When this
Collision Alert occurs, the brake system may
prepare for driver braking to occur more
rapidly which can cause a brief, mild
deceleration. Continue to apply the brake
pedal as needed. Cruise control may be
disengaged when the Collision Alert occurs.

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240 Driving and Operating
Warning (Continued)
vehicle. AEB will not brake outside of its
operating speed range and only responds
to detected vehicles.
AEB may not:
.Detect a vehicle ahead on winding or
hilly roads.
.Detect all vehicles, especially vehicles
with a trailer, tractors, muddy
vehicles, etc.
.Detect a vehicle when weather limits
visibility, such as in fog, rain, or snow.
.Detect a vehicle ahead if it is partially
blocked by pedestrians or other
objects.
Complete attention is always required
while driving, and you should be ready to
take action and apply the brakes and/or
steer the vehicle to avoid crashes.
AEB may slow the vehicle to a complete
stop to try to avoid a potential crash. If this
happens, AEB may engage the Electric
Parking Brake (EPB) to hold the vehicle at a
stop. Release the EPB or firmly press the
accelerator pedal.
{Warning
AEB may automatically brake the vehicle
suddenly in situations where it is
unexpected and undesired. It could
respond to a turning vehicle ahead,
guardrails, signs, and other non-moving
objects. To override AEB, firmly press the
accelerator pedal, if it is safe to do so.
Intelligent Brake Assist (IBA)
IBA may activate when the brake pedal is
applied quickly by providing a boost to
braking based on the speed of approach and
distance to a vehicle ahead.
Minor brake pedal pulsations or pedal
movement during this time is normal and
the brake pedal should continue to be
applied as needed. IBA will automatically
disengage only when the brake pedal is
released.
{Warning
IBA may increase vehicle braking in
situations when it may not be necessary.
You could block the flow of traffic. If this
occurs, take your foot off the brake pedal
and then apply the brakes as needed. AEB and IBA can be disabled through vehicle
personalization. See
“Collision/Detection
Systems” underVehicle Personalization
0 108.
{Warning
Using AEB or IBA while towing a trailer
could cause you to lose control of the
vehicle and crash. Turn the system to
Alert or Off when towing a trailer.
A system unavailable message may
display if:
.The front of the vehicle or windshield is
not clean.
.Heavy rain or snow is interfering with
object detection.
.There is a problem with the StabiliTrak/
Electronic Stability Control (ESC) system.
The AEB system does not need service.
Front Pedestrian Braking (FPB)
System
If equipped, the Front Pedestrian Braking
(FPB) system may help avoid or reduce the
harm caused by front-end crashes with
nearby pedestrians when driving in a
forward gear. FPB displays an amber