2021 GMC YUKON towing

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 253
Adaptive Cruise Control
(Advanced)
If equipped with Adaptive Cruise Control
(ACC), it allows for selecting the cruise
control set speed and following gap. Read
this entire section before using this system.
ACC uses a camera and radar sensor(s) to
detect other vehicles. SeeRadio Frequency
Statement 0407.
The following gap is the following time (or
distance) between your vehicle and a vehicle
detected directly ahead in your path,
moving in the same direction. If no vehicle
is detected in your path, ACC works like
regular cruise control.
If a vehicle is detected in your path, ACC can
apply acceleration or limited, moderate
braking to maintain the selected following
gap. To disengage ACC, apply the brake.
If ACC is controlling the vehicle speed when
the Traction Control System (TCS) or
StabiliTrak/Electronic Stability Control (ESC)
system activates, ACC may automatically
disengage. See Traction Control/Electronic
Stability Control 0242. When road
conditions allow ACC to be safely used, ACC
can be turned back on. Disabling the TCS or StabiliTrak/ESC system
will disengage and prevent engagement
of ACC.
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 0214.
{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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
260 Driving and Operating
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.
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.
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
System operation may be limited under
snow, heavy rain, or road spray conditions.
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.
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. See Roof Rack System 093. 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, and the sensors on the
front of the vehicle can become blocked by
snow, ice, dirt, mud, or debris. This area
needs to be cleaned for ACC to operate
properly.
If ACC will not operate, regular cruise control
may be available. See
“Switching Between
ACC and Regular Cruise Control” previously
in this section. Always consider driving
conditions before using either cruise control
system.
For cleaning instructions, see “Washing the
Vehicle” underExterior Care 0374.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
266 Driving and Operating
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 located in the customizing
menu is used to turn on or off the Park
Assist.
Front and Rear Park Assist can be set to Off,
On, or On with Towbar through vehicle
personalization. See “Park Assist”under
Vehicle Personalization 0126. If Park Assist
is turned off through vehicle personalization,
the Park Assist button will be disabled. To
turn the Park Assist on again, select On in
vehicle personalization. The On with Towbar
setting allows for Park Assist to work
properly with an attached trailer hitch. Turn
off Park Assist when towing a trailer.
To turn the RPA symbols, guidance lines,
or Rear Cross Traffic Alert on or off, see Rear
Camera and Collision/Detection Systems
under Vehicle Personalization 0126. On some models, select the guidance lines
button on the infotainment display to turn
them on or off.
Rear Pedestrian Alert
Under certain conditions, this feature can
provide alerts for a pedestrian within the
system’s range directly behind the vehicle.
This feature only works in R (Reverse) below
12 km/h (8 mph), and detects pedestrians up
to 8 m (26 ft) away during daytime driving.
During nighttime driving, feature
performance is very limited.
Rear Pedestrian Alert Indicator
When a pedestrian is detected within the
system’s range directly behind the vehicle,
this symbol flashes amber on the
infotainment display, along with two beeps
from the rear, or if equipped, two pulses
from both sides of the driver seat. When a
pedestrian is detected close to the vehicle,
the symbol flashes red on the infotainment display, along with seven beeps from the
rear, or if equipped, seven pulses from both
sides of the driver seat.
{Warning
Rear Pedestrian Alert does not
automatically brake the vehicle. It also
does not provide an alert unless it
detects a pedestrian, and it may not
detect all pedestrians if:
.The pedestrian is not directly behind
the vehicle, fully visible to the Rear
Vision Camera (RVC), or standing
upright.
.The pedestrian is part of a group.
.The pedestrian is a child.
.Visibility is poor, including nighttime
conditions, fog, rain, or snow.
.The RVC is blocked by dirt, snow,
or ice.
.The RVC, taillamps, or back-up lamps
are not cleaned or in proper working
condition.
.The vehicle is not in R (Reverse).
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
270 Driving and Operating
AEB may slow the vehicle to a complete
stop to try to avoid a potential crash. The
vehicle will only hold at a stop briefly.
A firm press of the accelerator pedal will
also release AEB.
{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
0 126.
{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 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 indicator,
~, when a nearby
pedestrian is detected ahead. When
approaching a detected pedestrian too
quickly, FPB provides a red flashing alert on
the windshield and rapidly beeps or pulses
the driver seat. FPB can provide a boost to
braking or automatically brake the vehicle.
This system includes Intelligent Brake Assist
(IBA), and the Automatic Emergency Braking
(AEB) system may also respond to
pedestrians. See Automatic Emergency
Braking (AEB) 0269.
The FPB system can detect and alert to
pedestrians in a forward gear at speeds
between 8 km/h (5 mph) and 80 km/h
(50 mph). During daytime driving, the
system detects pedestrians up to a distance
of approximately 40 m (131 ft). During
nighttime driving, system performance is
very limited.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
272 Driving and Operating
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 0126.
{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 Lane Change Alert (LCA)
system is a lane-changing aid that can assist
drivers with avoiding lane change crashes
with moving vehicles in the side blind zone,
or blind spot areas or with vehicles rapidly
approaching these areas from behind. When
a vehicle is detected in the blind zone, the
LCA warning display will light up in the
corresponding side mirror and will flash if
the turn signal is on. The Side Blind Zone
Alert (SBZA) system is included as part of
the LCA system.
{Warning
LCA does not alert the driver to vehicles
outside of the system detection zones,
pedestrians, bicyclists, or animals. It may
not provide alerts when changing lanes
under all driving conditions. Failure to use
proper care when changing lanes may
result in injury, death, or vehicle damage.
Before making a lane change, always
check mirrors, glance over your shoulder,
and use the turn signals.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 273
LCA Detection Zones
1. SBZA Detection Zone
2. LCA Detection Zone
When towing a trailer, LCA feature is
disabled. When not towing a trailer, the LCA
sensor covers a zone of approximately one
lane over from both sides of the vehicle,
or 3.5 m (11 ft). The height of the zone is
approximately between 0.5 m (1.5 ft) and
2 m (6 ft) off the ground. Drivers are also
warned of vehicles rapidly approaching this
area up to approximately 70 m (230 ft)
behind the vehicle.
Extended Side Blind Zone Area (ESBZA)
If equipped, the ESBZA system is a
lane-changing aid that assists drivers with
avoiding crashes that occur with moving
vehicles in the side blind zone, or blind spotareas. The extended side blind zone area
adds the blind zone area along the side of a
trailer that the host vehicle is pulling.
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
extended 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
system, read the entire Lane Change Alert
section before using this feature.
{Warning
ESBZA does not alert the driver to
vehicles outside of the system detection
zones, pedestrians, bicyclists, or animals.
It may not provide alerts when changing
lanes under all driving conditions. Failure
to use proper care when changing lanes
may result in injury, death, or vehicle
damage. Before making a lane change,
always check mirrors, glance over your
shoulder, and use the turn signals.
ESBZA Detection Zones
1. SBZA Detection Zone
2. ESBZA Detection Zone
3. LCA Detection Zone
The Side Blind Zone Alert (SBZA) warning
area starts at approximately the middle of
the vehicle and goes back 5 m (16 ft). The
Extended Side Blind Zone Alert (ESBZA)
warning area starts at approximately 3 m
(10 ft) to the trailing edge of the vehicle and
goes back up to 21 m (69 ft) behind the
vehicle. The maximum trailer length is
12 m (39 ft).
How the System Works
The LCA/ESBZA symbol lights up in the side
mirrors when the system detects a moving
vehicle in the next lane over that is in the
extended side blind zone. This indicates it
may be unsafe to change lanes. Before

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
274 Driving and Operating
making a lane change, check the SBZA
display, check mirrors, glance over your
shoulder, and use the turn signals.
Left Side MirrorDisplayRight Side Mirror Display
When the vehicle is started, both outside
mirror LCA/ESBZA displays will briefly come
on to indicate the system is operating.
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 in the
same direction as a detected vehicle, this
display will flash as an extra warning not to
change lanes.
LCA/ESBZA displays may not come on when
passing a vehicle quickly, or when passing a
stopped vehicle. LCA/ESBZA may alert to
objects attached to the vehicle, such as a
bicycle, or object extending out to either side of the vehicle or trailer. This is normal
system operation; the vehicle does not need
service.
LCA/ESBZA can be disabled through vehicle
personalization. See
“Collision/Detection
Systems” underVehicle Personalization
0 126. If SBZA is disabled by the driver, the
ESBZA mirror displays will not light up.When the System Does Not Seem to
Work Properly
LCA/ESBZA displays may not come on when
passing a vehicle quickly, or when passing a
stopped vehicle. The LCA/ESBZA detection
zones that extend back from the side of the
vehicle do not move further back when a
trailer is towed. Use caution while changing
lanes when towing a trailer. LCA/ESBZA may
alert to objects attached to the vehicle, such
as a trailer, bicycle, or object extending out
to either side of the vehicle or trailer. This is
normal system operation; the vehicle does
not need service.
LCA/ESBZA may not always alert the driver
to vehicles in the side blind zone, especially
in wet conditions. The system does not need
to be serviced. The system may light up due to guardrails, signs, trees, shrubs, and other
non-moving objects. This is normal system
operation; the vehicle does not need service.
LCA/ESBZA may not operate when the LCA/
ESBZA sensors in the left or right corners of
the rear bumper are covered with mud, dirt,
snow, ice, or slush, or in heavy rainstorms.
For cleaning instructions, see "Washing the
Vehicle" under
Exterior Care0374. If the DIC
displays the system unavailable message
after cleaning both sides of the vehicle
toward the rear corners of the vehicle, see
your dealer.
If the DIC displays the system unavailable
message after cleaning both sides of the
vehicle toward the rear corners of the
vehicle, see your dealer
If the LCA/ESBZA displays do not light up
when vehicles are in the blind zone and the
system is clean, the system may need
service. Take the vehicle to your dealer.
When ESBZA is disabled for any reason
other than the driver turning it off, the
Extended Side Blind Zone Alert On option
will not be available on the
personalization menu.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 275
Driving with a Trailer
Although this system is intended to help
drivers avoid lane change crashes, it does
not replace driver vision and therefore
should be considered a lane change aid.
Even with the ESBZA system, the driver
must check carefully for objects outside of
the reporting zone (e.g., a fast approaching
vehicle) or vehicle along the side of the
trailer before changing lanes.
Use caution while changing lanes when
towing a trailer.
Lane Keep Assist (LKA)
If equipped, LKA may help avoid crashes due
to unintentional lane departures. This
system uses a camera to detect lane
markings between 60 km/h (37 mph) and
180 km/h (112 mph). It may assist by gently
turning the steering wheel if the vehicle
approaches a detected lane marking. It may
also provide a Lane Departure Warning
(LDW) alert if the vehicle crosses a detected
lane marking. LKA can be overridden by
turning the steering wheel. This system is
not intended to keep the vehicle centered in
the lane. LKA will not assist and alert if theturn signal is active in the direction of lane
departure, or if it detects that you are
accelerating, braking, or actively steering.
{Warning
The LKA system does not continuously
steer the vehicle. It may not keep the
vehicle in the lane or give a Lane
Departure Warning (LDW) alert, even if a
lane marking is detected.
The LKA and LDW systems may not:
.Provide an alert or enough steering
assist to avoid a lane departure or
crash.
.Detect lane markings under poor
weather or visibility conditions. This
can occur if the windshield or
headlamps are blocked by dirt, snow,
or ice; if they are not in proper
condition; or if the sun shines directly
into the camera.
.Detect road edges.
.Detect lanes on winding or hilly roads.
If LKA only detects lane markings on one
side of the road, it will only assist or
provide an LDW alert when approaching (Continued)
Warning (Continued)
the lane on the side where it has
detected a lane marking. Even with LKA
and LDW, you must steer the vehicle.
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