2021 GMC YUKON tow

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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
280 Driving and Operating
Trailer Towing
General Towing Information
Only use towing equipment that has been
designed for the vehicle. Contact your dealer
or trailering dealer for assistance with
preparing the vehicle to tow a trailer. Read
the entire section before towing a trailer.
To tow a disabled vehicle, seeTowing the
Vehicle 0370. To tow the vehicle behind
another vehicle such as a motor home, see
Recreational Vehicle Towing 0371.
Driving Characteristics and
Towing Tips
{Warning
You can lose control when towing a
trailer if the correct equipment is not
used or the vehicle is not driven properly.
For example, if the trailer is too heavy or
the trailer brakes are inadequate for the
load, the vehicle may not stop as
expected. You and others could be
seriously injured. The vehicle may also be
damaged, and the repairs would not be
covered by the vehicle warranty. Pull a
(Continued)
Warning (Continued)
trailer only if all the steps in this section
have been followed. Ask your dealer for
advice and information about towing a
trailer with the vehicle.
Driving with a Trailer
Trailering is different than just driving the
vehicle by itself. Trailering means changes in
handling, acceleration, braking, durability,
and fuel economy. Successful, safe trailering
takes correct equipment, and it has to be
used properly.
The following information has many
time-tested, important trailering tips and
safety rules. Many of these are important
for your safety and that of your passengers.
Read this section carefully before pulling a
trailer.
When towing a trailer:
.Become familiar with and follow all state
and local laws that apply to trailer
towing. These requirements vary from
state to state.
.State laws may require the use of
extended side view mirrors. Even if not
required, you should install extended side
view mirrors if your visibility is limited or
restricted while towing.
.Do not tow a trailer during the first
800 km (500 mi) of vehicle use to prevent
damage to the engine, axle, or other
parts.
.It is recommended to perform the first oil
change before heavy towing.
.During the first 800 km (500 mi) of trailer
towing, do not drive over 80 km/h
(50 mph) and do not make starts at full
throttle.
.Vehicles can tow in D (Drive). Tow/Haul
Mode is recommended for heavier trailers.
SeeTow/Haul Mode 0235. If the
transmission downshifts too often, a
lower gear may be selected using Manual
Mode. See Manual Mode 0235.
If equipped, the following driver assistance
features should be turned off when towing
a trailer:
.Adaptive Cruise Control (ACC)
.Super Cruise Control
.Lane Keep Assist (LKA)
.Park Assist

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 281
.Automatic Parking Assist (APA)
.Reverse Automatic Braking (RAB)
If equipped, the following driver assistance
features should be turned to alert or off
when towing a trailer:
.Automatic Emergency Braking (AEB)
.Intelligent Brake Assist (IBA)
.Front Pedestrian Braking (FPB)
If equipped with Lane Change Alert (LCA),
the LCA 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.
If equipped with Rear Cross Traffic Alert
(RCTA), 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.
{Warning
When towing a trailer, exhaust gases
may collect at the rear of the vehicle and
enter if the liftgate, trunk/hatch,
or rear-most window is open. (Continued)
Warning (Continued)
When towing a trailer:
.Do not drive with the liftgate, trunk/
hatch, or rear-most window open.
.Fully open the air outlets on or under
the instrument panel.
.Also adjust the climate control system
to a setting that brings in only outside
air. See“Climate Control Systems” in
the Index.
For more information about carbon
monoxide, see Engine Exhaust 0231.
Towing a trailer requires experience. The
combination of the vehicle and trailer is
longer and not as responsive as the vehicle
itself. Get used to the handling and braking
of the combination by driving on a level
road surface before driving on public roads.
The trailer structure, the tires, and the
brakes must be all be rated to carry the
intended cargo. Inadequate trailer
equipment can cause the combination to
operate in an unexpected or unsafe manner.
Before driving, inspect all trailer hitch parts
and attachments, safety chains, electrical connectors, lamps, tires, and mirrors. See
Towing Equipment
0287. If the trailer has
electric brakes, start the combination
moving and then manually apply the trailer
brake controller to check the trailer brakes
work. During the trip, occasionally check
that the cargo and trailer are secure and
that the lamps and any trailer brakes are
working.
Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther