trailer GMC TERRAIN 2021 User Guide

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 213
cannot be applied or released. To prevent
draining the battery, avoid unnecessary
repeated cycles of the EPB.
The system has a red parking brake status
light and an amber service parking brake
warning light. SeeElectric Parking Brake
Light 095 and
Service Electric Parking Brake Light 095.
There are also parking brake-related Driver
Information Center (DIC) messages.
Before leaving the vehicle, check the red
parking brake status light to ensure that the
parking brake is applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch momentarily.
The red parking brake status light will flash
and then stay on once the EPB is fully
applied. If the red parking brake status light
flashes continuously, then the EPB is only
partially applied or there is a problem with
the EPB. A DIC message will display. Release
the EPB and try to apply it again. If the
light does not come on, or keeps flashing, have the vehicle serviced. Do not drive the
vehicle if the red parking brake status light
is flashing. See your dealer.
If the amber service parking brake warning
light is on, press the EPB switch. Continue to
hold the switch until the red parking brake
status light remains on. If the amber service
parking brake warning light is on, see your
dealer.
If the EPB is applied while the vehicle is
moving, the vehicle will decelerate as long
as the switch is pressed. If the switch is
pressed until the vehicle comes to a stop,
the EPB will remain applied.
The vehicle may automatically apply the EPB
in some situations when the vehicle is not
moving. This is normal, and is done to
periodically check the correct operation of
the EPB system, or at the request of other
safety functions that utilize the EPB.
If the EPB fails to apply, block the rear
wheels to prevent vehicle movement.
EPB Release
To release the EPB:
1. Turn the ignition on or to ACC/ ACCESSORY.
2. Apply and hold the brake pedal. 3. Press the EPB switch momentarily.
The EPB is released when the red parking
brake status light is off.
If the amber service parking brake warning
light is on, release the EPB by pressing and
holding the EPB switch. Continue to hold the
switch until the red parking brake status
light is off. If either light stays on after
release is attempted, see your dealer.
Caution
Driving with the parking brake on can
overheat the brake system and cause
premature wear or damage to brake
system parts. Make sure that the parking
brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and parking on a
hill, see Driving Characteristics and Towing
Tips 0249.
Automatic EPB Release
The EPB will automatically release if the
vehicle is running, placed into gear, and an
attempt is made to drive away. Avoid rapid
acceleration when the EPB is applied, to
preserve parking brake lining life.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 219
If the vehicle is in Tour (FWD) or AWD, it
will stay in that mode through future
ignition cycles. If the vehicle is in any other
mode, it will revert back to Tour (FWD)
when the vehicle is restarted.
4AWD Mode :AWD Mode provides drive
torque to all four wheels. Select AWD to
improve traction and control on slippery
road surfaces, such as gravel, sand, wet
pavement, snow, and ice. When selecting
AWD Mode, the AWD light will flash briefly
while the system is engaging and then stay
on to indicate AWD is active. AWD is active
in Tow/Haul and Off-Road Modes. AWD
Mode is only available on vehicles equipped
with AWD.
When using a compact spare tire on an
AWD vehicle, the system automatically
detects the compact spare and reduces AWD
performance to protect the system. To
restore full AWD operation and prevent
excessive wear on the system, replace the
compact spare tire with a full-size tire as
soon as possible. See Compact Spare Tire
0 315.
6Snow Mode : Snow Mode improves
vehicle acceleration on snow and ice-covered
roads. Snow Mode is not available on
vehicles equipped with AWD.
7Off-Road Mode : Use Off-Road Mode for
public off-road recreational driving. See
Off-Road Driving 0190. Off-Road Mode is
only available on vehicles equipped
with AWD.
_Tow/Haul Mode : Tow/Haul Mode can
assist when towing or hauling a heavy load.
It changes transmission shift patterns, turns
on AWD, if equipped, and increases trailer
sway control assistance. See Driving
Characteristics and Towing Tips 0249. Tow/
Haul Mode is only available on vehicles with
the towing package. Automatic Engine Grade Braking
Automatic Engine Grade Braking assists
when driving downhill. It maintains vehicle
speed by automatically implementing a shift
pattern that uses the engine and the
transmission to slow the vehicle. The system
will automatically command downshifts to
reduce vehicle speed. The normal shift
pattern will return once the vehicle is on a
low grade or when the accelerator pedal is
pressed.
While in the Electronic Range Select (ERS)
Mode, grade braking is deactivated, allowing
a range to be selected and limiting the
highest gear available. Grade braking is
available for normal driving and in Tow/Haul
Mode. See
Manual Mode 0211.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
Mexico-14420055) - 2021 - CRC - 11/13/20
220 Driving and Operating
Mode Name In Cluster Menu:TourAWD Snow Off-Road Tow/Haul
Mode Availability AWD & FWD AWD FWD AWD Towing Package
(AWD & FWD)
Retained Across Ignition Cycles YesYesNoNo No
Pedal Map Normal Normal Off-Road Off-Road Normal
Auto Transmission Schedule Normal Normal Normal Normal Tow/Haul
AWD (If Equipped) Normal FWD Normal AWD NA Off-Road AWD Normal AWD
Steering Normal Normal Normal Normal Tow/Haul
Trailer Sway Control Normal Normal Normal Normal Tow/Haul
StabiliTrak Setting Normal Normal Normal Off-Road Normal
Traction Control Setting Normal Normal Normal Off-Road Normal
Cruise Control
The cruise control lets the vehicle maintain a
speed of about 40 km/h (25 mph) or more
without keeping your foot on the
accelerator. Cruise control does not work at
speeds below 40 km/h (25 mph).
{Warning
Cruise control can be dangerous where
you cannot drive safely at a steady
speed. Do not use cruise control on
winding roads or in heavy traffic.
Cruise control can be dangerous on
slippery roads. On such roads, fast
changes in tire traction can cause
(Continued)
Warning (Continued)
excessive wheel slip, and you could lose
control. Do not use cruise control on
slippery roads.
With the Traction Control System (TCS) or
StabiliTrak/Electronic Stability Control (ESC),
the system may begin to limit wheel spin
while you are using cruise control. If this
happens, the cruise control will

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
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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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/
Mexico-14420055) - 2021 - CRC - 11/13/20
Driving and Operating 235
active. Touching the button multiple times
will toggle between forward and rearward
views. Park Assist and RCTA are not available
when Bowl view is active.
Side Forward/Rearward View :Displays a
view that shows objects next to the front or
rear sides of the vehicle. Touch Side
Forward/Rearward View on the infotainment
display when a camera view is active.
Touching the button multiple times will
toggle between forward and rearward views.
Park Assist and RCTA overlays are not
available when Side Forward/Rearward view
is active.
Hitch View : If equipped, assists while
connecting to a trailer. Displays a zoomed-in
view of the hitch to help align the vehicle’s
hitch ball with the trailer coupler.
Guidance Lines : Displays available
guidelines. The horizontal markings
represent distance from the vehicle.
Top Down View : Displays an image of the
area surrounding the vehicle, along with
other views in the infotainment display. Top
down can be enabled or disabled by
pressing the Top Down View button multiple
times. Park Assist
With RPA, and if equipped with FPA, as the
vehicle moves at speeds of less than 8 km/h
(5 mph), the sensors on the bumpers may
detect objects up to 2.5 m (8 ft) behind the
vehicle and 1.2 m (4 ft) in front of the
vehicle within a zone 25 cm (10 in) high off
the ground and below bumper level. These
detection distances may be shorter during
warmer or humid weather. Blocked sensors
will not detect objects and can also cause
false detections. Keep the sensors clean of
mud, dirt, snow, ice, and slush; and clean
sensors after a car wash in freezing
temperatures.
{Warning
The Park Assist system does not detect
children, pedestrians, bicyclists, animals,
or objects located below the bumper or
that are too close or too far from the
vehicle. It is not available at speeds
greater than 8 km/h (5 mph). To prevent
injury, death, or vehicle damage, even
with Park Assist, always check the area
around the vehicle and check all mirrors
before moving forward or backing.
The instrument cluster may have a Park
Assist display with bars that show
“distance
to object” and object location information
for the Park Assist system. As the object
gets closer, more bars light up and the bars
change color from yellow to amber to red.
When an object is first detected in the rear,
both sides of the Safety Alert Seat will pulse
two times. When an object is very close
(<0.6 m (2 ft) in the vehicle rear, or <0.3 m
(1 ft) in the vehicle front), five beeps will
sound from the front or rear depending on
object location, or both sides of the Safety
Alert Seat will pulse five times. Beeps for
FPA are higher pitched than for RPA.
Rear Cross Traffic Alert (RCTA)
If equipped, when the vehicle is shifted into
R (Reverse), RCTA displays a red warning
triangle with a left or right pointing arrow
to warn of traffic coming from the left or

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.

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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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

GMC Terrain/Terrain Denali Owner Manual(GMNA-Localizing-U.S./Canada/
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242 Driving and Operating
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 Front Pedestrian Alert occurs.
Automatic Braking
If FPB detects it is about to crash into a
pedestrian directly ahead, and the brakes
have not been applied, FPB may
automatically brake moderately or brake
hard. This can help to avoid some very low
speed pedestrian crashes or reduce
pedestrian injury. FPB can automatically
brake to detected pedestrians between
8 km/h (5 mph) and 80 km/h (50 mph).
Automatic braking levels may be reduced
under certain conditions, such as higher
speeds.
If this happens, Automatic Braking may
engage the Electric Parking Brake (EPB) to
hold the vehicle at a stop. Release the EPB.
A firm press of the accelerator pedal will
also release Automatic Braking and the EPB.
{Warning
FPB may alert or automatically brake the
vehicle suddenly in situations where it is
unexpected and undesired. It could falsely
alert or brake for objects similar in shape
or size to pedestrians, including shadows.
This is normal operation and the vehicle
does not need service. To override
Automatic Braking, firmly press the
accelerator pedal, if it is safe to do so.
Automatic Braking can be disabled through
vehicle personalization. See “Front Pedestrian
Detection” in“Collision/Detection Systems”
under Vehicle Personalization 0108.
{Warning
Using the Front Pedestrian Braking
system 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.
Cleaning the System
If FPB does not seem to operate properly,
cleaning the outside of the windshield in
front of the rearview mirror may correct the
issue.
Side Blind Zone Alert (SBZA)
If equipped, the SBZA system is a
lane-changing aid that assists drivers with
avoiding crashes that occur with moving
vehicles in the side blind zone, or blind spot
areas. When the vehicle is in a forward gear,
the left or right side mirror display will light
up if a moving vehicle is detected in that
blind zone. If the turn signal is activated and
a vehicle is also detected on the same side,
the display will flash as an extra warning
not to change lanes. Since this system is
part of the Lane Change Alert (LCA) system,
read the entire LCA section before using this
feature.
Lane Change Alert (LCA)
If equipped, the LCA system is a
lane-changing aid that assists drivers with
avoiding lane change crashes that occur with
moving vehicles in the side blind zone (or
spot) areas or with vehicles rapidly
approaching these areas from behind. The