2021 GMC YUKON sensor

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./
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258 Driving and Operating
Irregular Objects Affecting ACC
ACC may have difficulty detecting the
following objects:
.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.
.Objects that are close to the front of your
vehicle.
ACC Automatically Disengages
ACC may automatically disengage and the
driver will need to manually apply the
brakes to slow the vehicle if:
.The sensors are blocked.
.The Traction Control System (TCS) or
StabiliTrak/ESC system has activated or
been disabled.
.There is a fault in the system.
.The radar falsely reports blockage when
driving in a desert or remote area with
no other vehicles or roadside objects.
A DIC message may display 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” previously 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 0126.
When the vehicle ahead drives away, 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 0240. A DIC warning message may display
indicating to shift to P (Park) before exiting
the vehicle. See
Vehicle Messages 0125.
{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 indicating ACC braking
will not occur. ACC will resume operation
when the accelerator pedal is not being
pressed.

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
Driving and Operating 261
{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. SeeDefensive Driving 0214.
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.
.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. (Continued)
Warning (Continued)
.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 0126.
If equipped with the Safety Alert Seat, the
driver seat cushion may provide a vibrating
pulse alert instead of beeping. To change
this, see “Collision/Detection Systems” under
Vehicle Personalization 0126.
Cleaning
Depending on vehicle options, keep these
areas of the vehicle clean to ensure the best
driver assistance feature performance. Driver Information Center (DIC) messages may
display when the systems are unavailable or
blocked.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 265
Warning (Continued)
mirrors and glance over your shoulder.
Improper use could result in serious
injury to you or others.
Park Assist
The vehicle may be equipped with the Rear
Park Assist (RPA) and Front Park Assist (FPA).
The Park Assist system may provide
assistance to driver while backing up and
parking. Park Assist uses ultrasonic sensors
in the bumper to measure the distance
between the vehicle and objects. The system
calculates the distance between vehicle and
object via measuring the time it takes for
the ultrasonic waves to bounce back from
the object. Park Assist works only at speeds
up to about 11 Km/h (7 mph). An illuminated
indicater light in the parking system is
ready to operate. The sensors on the
bumpers may detect objects up to 1.8m
(6 ft) behind and 1.25m (4 ft) in front of the
vehicle within a one 25 cm (10) 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 wash in freezing
temperatures.
{Warning
The Park Assist System is no substitute
for careful and attentive driving. 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 11 km/h
(7 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.
How the system works
The instrument cluster may have a Park
Assist display with bars that show distance
to object, driving direction, 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 very close to the vehicle
rear (<0.6m (2 ft)), five beeps will sound
from the rear followed by a continuous
beep from the rear, or both sides of the
Safety Alert Seat will pulse five times. When
an object is very close to the vehicle front
(<0.3m (1 ft)), a continuous beep will sound
from the front, 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
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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
268 Driving and Operating
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,
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
With Head-Up Display
Without Head-Up Display
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.
Tailgating Alert
The vehicle-ahead indicator will display
amber when you are following a vehicle
ahead much too closely.
Selecting the Alert Timing
The Collision Alert control is on the steering
wheel. Press
[/3to set the FCA
timing to Far, Medium, Near, or on some
vehicles, Off. The first button press shows
the current setting on the DIC. Additional
button presses will change this setting. The
chosen setting will remain until it is
changed and will affect the timing of both
the Collision Alert and the Tailgating Alert
features. The timing of both alerts will vary
based on vehicle speed. The faster the
vehicle speed, the farther away the alert will
occur. Consider traffic and weather
conditions when selecting the alert timing.
The range of selectable alert timing may not
be appropriate for all drivers and driving
conditions.
If your vehicle is equipped with Adaptive
Cruise Control (ACC), changing the FCA
timing setting automatically changes the
ACC following gap setting (Far, Medium,
or Near).

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 269
Following Distance Indicator
The following distance to a moving vehicle
ahead in your path is indicated in following
time in seconds on the Driver Information
Center (DIC). SeeDriver Information Center
(DIC) 0120. The minimum following time is
0.5 seconds away. If there is no vehicle
detected ahead, or the vehicle ahead is out
of sensor range, dashes will be displayed.
Unnecessary Alerts
FCA may provide unnecessary alerts for
turning vehicles, vehicles in other lanes,
objects that are not vehicles, or shadows.
These alerts are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to operate
properly, this may correct the issue:
.Clean the outside of the windshield in
front of the rearview mirror.
.Clean the entire front of the vehicle.
.Clean the headlamps.
For cleaning instructions, see “Washing the
Vehicle” underExterior Care 0374.
System operation may also be limited under
snow, heavy rain, or road spray conditions.
Automatic Emergency
Braking (AEB)
If the vehicle has Forward Collision Alert
(FCA), it also has AEB, which includes
Intelligent Brake Assist (IBA). When the
system detects a vehicle ahead in your path
that is traveling in the same direction that
you may be about to crash into, it can
provide a boost to braking or automatically
brake the vehicle. This can help avoid or
lessen the severity of crashes when driving
in a forward gear. Depending on the
situation, the vehicle may automatically
brake moderately or hard. This automatic
emergency braking can only occur if a
vehicle is detected. This is shown by the FCA
vehicle ahead indicator being lit. See
Forward Collision Alert (FCA) System 0267.
The system works when driving in a forward
gear between 8 km/h (5 mph) and 80 km/h
(50 mph), or on vehicles with Adaptive
Cruise Control (ACC), above 4 km/h (2 mph).
It can detect vehicles up to approximately
60 m (197 ft).
{Warning
AEB is an emergency crash preparation
feature and is not designed to avoid
crashes. Do not rely on AEB to brake the
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 271
{Warning
FPB does not provide an alert or
automatically brake the vehicle, unless it
detects a pedestrian. FPB may not detect
pedestrians, including children:
.When the pedestrian is not directly
ahead, fully visible, or standing
upright, or when part of a group.
.Due to poor visibility, including
nighttime conditions, fog, rain,
or snow.
.If the FPB sensor is blocked by dirt,
snow, or ice.
.If the headlamps or windshield are not
cleaned or in proper condition.
Be ready to take action and apply the
brakes. For more information, see
Defensive Driving 0214. Keep the
windshield, headlamps, and FPB sensor
clean and in good repair.
FPB can be set to Off, Alert, or Alert and
Brake through vehicle personalization. See
“Collision/Detection Systems” underVehicle
Personalization 0126.
Detecting the Pedestrian Ahead
FPB alerts and automatic braking will not
occur unless the FPB system detects a
pedestrian. When a nearby pedestrian is
detected in front of the vehicle, the
pedestrian ahead indicator will display
amber.
Front Pedestrian Alert
With Head-Up Display
Without Head-Up Display
When the vehicle approaches a pedestrian
ahead too rapidly, the red FPB alert display
will flash on the windshield. Eight rapid
high-pitched beeps will sound from the
front, or both sides of the Safety Alert Seat
will pulse five times. When this Pedestrian
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 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