change time GMC YUKON 2021 Service Manual

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
256 Driving and Operating
The set speed can also be increased while
the vehicle is stopped.
.If stopped with the brake pedal 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
with cause the 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.
.Press and hold SET– until the desired
lower speed is reached, then release it.
.To decrease the vehicle speed in smaller
increments, press SET− down briefly. For
each press, the vehicle goes about 1 km/h
or (1 mph) slower.
.To decrease the vehicle speed in larger
increments, hold SET−. While holding SET
−, the vehicle speed decreases to the next
5 km/h (5 mph) step, then continues to
decrease by 5 km/h (5 mph) at a time.
The set speed can also be decreased while
the vehicle is stopped.
.If stopped with the brake applied, press
or hold SET− until the desired set speed is
displayed.
Selecting the Follow Distance Gap
When a slower moving vehicle is detected
ahead within the selected following gap,
ACC will adjust the vehicle's speed and
attempt to maintain the follow distance gap
selected.
Press
[on the steering wheel to adjust
the following gap. Each press cycles the gap
button through three settings: Far, Medium,
or Near.
When pressed, the current gap setting
displays briefly on the instrument cluster
and HUD (if equipped). The gap setting will
be maintained until it is changed. Since each gap setting corresponds to a
following time (Far, Medium, or Near), the
following distance will vary based on vehicle
speed. The faster the vehicle speed, the
further back your vehicle will follow a
vehicle detected ahead. Consider traffic and
weather conditions when selecting the
following gap. The range of selectable gaps
may not be appropriate for all drivers and
driving conditions.
Changing the gap setting automatically
changes the alert timing sensitivity (Far,
Medium, or Near) for the Forward Collision
Alert (FCA) feature. See
Forward Collision
Alert (FCA) System 0267.
Alerting the Driver
With Head-Up Display

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 257
Without Head-Up Display
If ACC is engaged, driver action may be
required when ACC cannot apply sufficient
braking because of approaching a vehicle
too rapidly.
When this condition occurs, the collision
alert symbol will flash on the windshield.
Either eight beeps will sound from the front,
or both sides of the Safety Alert Seat (if
equipped) will pulse five times. See
“Collision/Detection Systems” underVehicle
Personalization 0126
See Defensive Driving 0214.
Approaching and Following a Vehicle
The vehicle ahead indicator is in the
instrument cluster and HUD, if equipped.
It only displays when a vehicle is detected
in your vehicle’s path moving in the same
direction. If this symbol is not displaying,
ACC will not respond to or brake for vehicles
ahead.
ACC automatically slows the vehicle down
and adjusts vehicle speed to follow a
detected vehicle ahead at the selected
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 259
{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.
{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 (Continued)
Warning (Continued)
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 briefly 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

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
264 Driving and Operating
Front/Rear Standard View :Displays an
image of the area in front or behind the
vehicle. Touch Front/Rear Standard View on
the infotainment display when a camera
view is active. Touching the button multiple
times will toggle between front and rear
camera views.
If equipped, the front view camera also
displays when the Park Assist system
detects an object within 30 cm (12 in).
Front/Rear Junction View : Displays a front
or rear cross traffic view that shows objects
directly to the left and right of the front or
back of the vehicle. Touch Junction View on
the infotainment display when a camera
view is active. Touching the button multiple
times will toggle between front and rear
camera views.
Front/Rear Overhead View : Displays a Front
or Rear Overhead View of the vehicle.
Touching the button will toggle between the
two views.
Front/Rear Bowl View : Displays a view of
the vehicle from either the front or the back
of the vehicle. Touch Bowl 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 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. Shifting
into P (Park) while in this view will
automatically engage the Electric Parking
Brake (EPB).
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. Hitch Guidance
If equipped, the feature displays a single,
centered guideline on the camera display to
assist with aligning a vehicles hitch ball with
a trailer coupler. Select the trailer guidance
line button, then align the trailer guidance
line over the trailer coupler. Continuously
steer the vehicle to keep the guidance line
centered on the coupler when backing. RVC
Park Assist overlays will not display when
the trailer guidance line is active. Hitch
Guidance is only available in Standard View.
To check the trailer when in a forward gear
above 12 km/h (8 mph), touch CAMERA on
the infotainment display to view the rear
camera. Touch X to exit the view or it will
be removed automatically after
eight seconds.
{Warning
Use Hitch Guidance only to help back the
vehicle to a trailer hitch or, when
traveling above 12 km/h (8 mph), to
briefly check the status of your trailer. Do
not use for any other purpose, such as
making lane change decisions. Before
making a lane change, always check the
(Continued)

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./
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Driving and Operating 267
Warning (Continued)
To help avoid death or injury, always
check for pedestrians around the vehicle
before backing up. Be ready to take
action and apply the brakes. See
Defensive Driving0214. Keep the RVC,
taillamps, and back-up lamps clean and in
good repair.
Rear Pedestrian Alert can be set to Off or
Alert. See “Rear Pedestrian Detection” in
“Collision/Detection Systems” underVehicle
Personalization 0126. If equipped, alerts can
be set to beeps or seat pulses. See “Alert
Type” in“Collision/Detection Systems” under
Vehicle Personalization 0126.
Assistance Systems for Driving
If equipped, when driving the vehicle in a
forward gear, Forward Collision Alert (FCA),
Front Pedestrian Braking (FPB), Lane Keep
Assist (LKA), Side Blind Zone Alert (SBZA),
Lane Change Alert (LCA), and/or Automatic
Emergency Braking (AEB) 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.
FCA detects vehicles within a distance of
approximately 60 m (197 ft) and operates at
speeds above 8 km/h (5 mph). If the vehicle
has Adaptive Cruise Control (ACC), it can
detect vehicles to distances of approximately
110 m (360 ft) and operates at all speeds.
See Adaptive Cruise Control (Advanced)
0 253.
{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
(Continued)
Warning (Continued)
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
0 214.
FCA can be disabled with either the FCA
steering wheel control or, if equipped,
through vehicle personalization. See
“Collision/Detection Systems” underVehicle
Personalization 0126.
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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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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./
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276 Driving and Operating
audible alert or the driver seat may pulse
indicating that a lane marking has been
crossed.
To turn LKA on and off, press
Ato the
left of the steering wheel. If equipped, the
indicator light on the button comes on
when LKA is on and turns off when LKA is
disabled.
When on,
Ais white, if equipped,
indicating that the system is not ready to
assist.
Ais green if LKA is ready to
assist. LKA may assist by gently turning the
steering wheel if the vehicle approaches a
detected lane marking.
Ais amber when
assisting. It may also provide a Lane
Departure Warning (LDW) alert by flashing
Aamber if the vehicle crosses a
detected lane marking. Additionally, there
may be three beeps, or the driver seat may
pulse three times, on the right or left,
depending on the lane departure direction.
Take Steering
The LKA system does not continuously steer
the vehicle. If LKA does not detect active
driver steering, an alert and chime may be
provided. Steer the vehicle to dismiss. LKA
may become temporarily unavailable after
repeated take steering alerts.
When the System Does Not Seem to
Work Properly
The system performance may be
affected by:
.Close vehicles ahead.
.Sudden lighting changes, such as when
driving through tunnels.
.Banked roads.
.Roads with poor lane markings, such as
two-lane roads.
If the LKA system is not functioning
properly when lane markings are clearly
visible, cleaning the windshield may help.
A camera blocked message may display if
the camera is blocked. Some driver
assistance systems may have reduced
performance or not work at all. An LKA or
LDW unavailable message may display if the
systems are temporarily unavailable. This
message could be due to a blocked camera.
The LKA system does not need service. Clean
the outside of the windshield behind the
rearview mirror.
LKA assistance and/or LDW alerts may occur
due to tar marks, shadows, cracks in the
road, temporary or construction lane
markings, or other road imperfections. This is normal system operation; the vehicle does
not need service. Turn LKA off if these
conditions continue.
Fuel
Top Tier Fuel
GM recommends the use of TOP TIER
Detergent Gasoline to keep the engine clean,
reduce engine deposits, and maintain
optimal vehicle performance. Look for the
TOP TIER Logo or see www.toptiergas.com
for a list of TOP TIER Detergent Gasoline
marketers and applicable countries.