warning GMC YUKON 2020 Owner's Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
214 Driving and Operating
To rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission, seeIf
the Vehicle Is Stuck 0195.
N : In this position, the engine does
not connect with the wheels. To
restart the engine when the vehicle
is already moving, use
N (Neutral) only.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.
Caution
Shifting out of P (Park) or
N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.
Caution
A transmission hot message may
display if the automatic
transmission fluid is too hot.
Driving under this condition can
damage the vehicle. Stop and idle
the engine to cool the automatic
transmission fluid. This message
clears when the transmission fluid
has cooled sufficiently.
D : This position is for normal
driving. If more power is needed for
passing, press the accelerator
pedal down. Use D (Drive) and Tow/Haul Mode
when towing a trailer, carrying a
heavy load, driving on steep hills,
or driving off-road. Shift the
transmission to a lower gear
selection if the transmission shifts
too often.
Downshifting the transmission in
slippery road conditions could result
in skidding. See
“Skidding”under
Loss of Control 0187.
The vehicle has a shift stabilization
feature that adjusts the transmission
shifting to the current driving
conditions in order to reduce rapid
upshifts and downshifts. This shift
stabilization feature is designed to
determine, before making an
upshift, if the engine is able to
maintain vehicle speed by analyzing
things such as vehicle speed,
throttle position, and vehicle load.
If the shift stabilization feature
determines that a current vehicle
speed cannot be maintained, the
transmission does not upshift and
instead holds the current gear.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 219
To disable or enable Tow/Haul
Grade Braking within the current
ignition cycle, press and hold the
Tow/Haul button for five seconds.
When the button is released, the
requested mode change is made.
A DIC message is displayed.
SeeTowing Equipment 0270.
For other forms of grade braking,
see Automatic Transmission 0213
and
Cruise Control 0230.Drive Systems
Four-Wheel Drive
If equipped, four-wheel drive
engages the front axle for extra
traction.
Caution
Do not drive on clean, dry
pavement in 4
mand 4n(if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle’s powertrain.
Driving on clean, dry pavement in 4
mor 4nmay:
. Cause a vibration to be felt in
the steering system.
. Cause tires to wear faster.
. Make the transfer case harder to
shift, and cause it to run noisier.
{Warning
Shifting the transfer case to
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or someone else
could be seriously injured. Be
sure to set the parking brake
before placing the transfer case in
N (Neutral). See Parking Brake
0 225.
Caution
Extended high-speed operation in
4
nmay damage or shorten the
life of the drivetrain.
Engagement noise and bump when
shifting between 4
nand 4mor from
N (Neutral), with the engine running,
is normal.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
224 Driving and Operating
Shifting Into 4mor AUTO
Turn the knob to the 4
mor AUTO
position. This can be done at any
speed. The indicator light will flash
while shifting. It will remain on when
the shift is completed.
Shifting Into 2
m
Turn the knob to the 2mposition.
This can be done at any speed. The
indicator light will flash while
shifting. It will remain on when the
shift is completed.
Brakes
Antilock Brake
System (ABS)
The Antilock Brake System (ABS)
helps prevent a braking skid and
maintain steering while
braking hard.
ABS performs a system check when
the vehicle is first driven.
A momentary motor or clicking noise
may be heard while this test is going
on, and the brake pedal may move
slightly. This is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
0 138. ABS does not change the time
needed to get a foot on the brake
pedal and does not always
decrease stopping distance. If you
get too close to the vehicle ahead,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room ahead to stop,
even with ABS.
Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly.
Hearing or feeling ABS operate is
normal.
Braking in Emergencies
ABS allows steering and braking at
the same time. In many
emergencies, steering can help
even more than braking.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 225
Parking Brake
Set the parking brake by holding the
regular brake pedal down, then
pushing down the parking brake
pedal.
If the ignition is on, the brake
system warning light will come on.
SeeBrake System Warning Light
0 138.
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.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the parking brake pedal.
If the parking brake is not released
when you begin to drive, a DIC
message will appear and a chime
will sound warning you that the
parking brake is still on.
Brake Assist
Brake Assist detects rapid brake
pedal applications due to
emergency braking situations and
provides additional braking to
activate the Antilock Brake System (ABS) if the brake pedal is not
pushed hard enough to activate
ABS normally. Minor noise, brake
pedal pulsation, and/or pedal
movement during this time may
occur. Continue to apply the brake
pedal as the driving situation
dictates. Brake Assist disengages
when the brake pedal is released.
Hill Start Assist (HSA)
{Warning
Do not rely on the HSA feature.
HSA does not replace the need to
pay attention and drive safely.
You may not hear or feel alerts or
warnings provided by this system.
Failure to use proper care when
driving may result in injury, death,
or vehicle damage. See
Defensive Driving
0185.
When the vehicle is stopped on a
grade, Hill Start Assist (HSA)
temporarily prevents the vehicle
from rolling in an unintended
direction during the transition from

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
230 Driving and Operating
Cruise Control
{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 excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.
With cruise control a speed of about
40 km/h (25 mph) or more can be
maintained without keeping your
foot on the accelerator. Cruise
control does not work at speeds
below about 40 km/h (25 mph).
If the brakes are applied, the cruise
control disengages.
For an explanation of how cruise
control interacts with the Range
Selection Mode, Tow/Haul Mode, and Grade Braking systems. See
“Grade Braking”
underTow/Haul
Mode 0218.
This vehicle has StabiliTrak and
when the system begins to limit
wheel spin, the cruise control will
automatically disengage. See
Traction Control/Electronic Stability
Control 0226. If a collision alert
occurs when cruise control is
activated, cruise control is
disengaged. See Forward Collision
Alert (FCA) System 0245. When
road conditions allow the cruise
control to be safely used again, it
can be turned back on.
5: Press to turn the system on or
off. A white indicator comes on in
the instrument cluster when the
cruise is turned on.
SET− :Press briefly to set the
speed and activate cruise control.
If cruise control is already active,
use to decrease vehicle speed.
+RES : If there is a set speed in
memory, press to resume that
speed or press and hold to
accelerate. If cruise control is
already active, use to increase
vehicle speed.
*: Press to disengage cruise
control without erasing the set
speed from memory.
Setting Cruise Control
If
5is on when not in use, SET− or
+RES could get pressed and go into
cruise when not desired. Keep the
cruise
5button off when cruise is
not being used.
1. Press
5to turn the cruise
system on.
2. Get up to the desired speed.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
232 Driving and Operating
may be necessary to maintain
vehicle speed. When going
downhill, Cruise Grade Braking
helps maintain the driver selected
speed.
Cruise Grade Braking is enabled
when the vehicle is started and
cruise control is active. It is not
enabled in Range Selection Mode.
It assists in maintaining driver
selected speed when driving on
downhill grades by using the engine
and transmission to slow the
vehicle.
To disable and enable Cruise Grade
Braking for the current ignition key
cycle, press and hold the Tow/Haul
button for five seconds. A DIC
message displays.
For other forms of Grade Braking,
seeAutomatic Transmission 0213
and
Tow/Haul Mode 0218.
Ending Cruise Control
There are four ways to end cruise
control:
. Step lightly on the brake pedal. .
Press*.
. Shift the transmission to
N (Neutral).
. To turn off cruise control,
press
5.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5is pressed
or if the ignition is turned off.
Adaptive Cruise Control
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
sensors to detect other vehicles.
See Radio Frequency Statement
0 405. 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 speed up the vehicle or
apply limited, moderate braking to
maintain the selected following gap.
To disengage ACC, apply the brake.
If the Traction Control System (TCS)
or electronic stability control system
activates while ACC is engaged,
ACC may automatically disengage.
See
Traction Control/Electronic
Stability Control 0226. When road
conditions allow ACC to be safely
used, the ACC can be turned
back on.
ACC will not engage if the TCS or
electronic stability control system is
disabled.
{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.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 233
Warning (Continued)
Also see“Alerting the Driver” 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 0185.
{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 sensors are
blocked by snow, ice, or dirt.
The system may not detect
a vehicle ahead. Keep the
entire front of the vehicle
clean.
(Continued)
Warning (Continued)
.Visibility is low, such as in
fog, rain, or snow
conditions. ACC
performance is limited under
these conditions.
. On slippery roads where
fast changes in tire traction
can cause excessive
wheel slip.
5: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 hold to
accelerate. If ACC is already
engaged, use to increase vehicle
speed.
SET– :Press briefly to set the
speed and activate ACC. If cruise
control is already engaged, use to
decrease vehicle speed.
*: Press to disengage ACC
without erasing the selected set
speed.
3: Press to select a following gap
time (or distance) setting for ACC of
Far, Medium, or Near.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster 0126.
The increment value used depends
on the units displayed.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 237
selected follow gap. The vehicle
speed increases or decreases to
follow the vehicle in front of you, but
will not exceed the set speed. It may
apply limited braking, if necessary.
When braking is active, the brake
lights will come on. The automatic
braking may feel or sound different
than if the brakes were applied
manually. This is normal.
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(Continued)
Warning (Continued)
attention is always required while
driving and you should be ready
to take action and apply the
brakes.
ACC Automatically Disengages
ACC may automatically disengage
and you will need to manually apply
the brakes to slow the vehicle if:
. Your vehicle speed goes below
the minimum speed of 16 km/h
(10 mph).
. The sensors are blocked.
. The Traction Control System
(TCS) or electronic stability
control system has activated or
been disabled.
. There is a fault in the system.
. The radar falsely reports a
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.
A message will appear on the DIC
indicating that cruise is disengaging.
The ACC indicator will turn white
when ACC is no longer active.
Notification to Resume ACC
ACC will maintain a following gap
behind a detected vehicle and slow
your vehicle to a stop behind the
detected 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” under
Vehicle Personalization 0152.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
238 Driving and Operating
When the vehicle ahead drives
away, press +RES or the
accelerator pedal to resume cruise
control.
A DIC warning message may
display indicating to shift to P (Park)
before exiting the vehicle. See
Vehicle Messages0151.
{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
(Continued)
Warning (Continued)
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
and in the HUD (if equipped) to
indicate that automatic braking will
not occur. ACC will resume
operation when the accelerator
pedal is not being pressed.
{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
attention in curves and be ready
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 239
Warning (Continued)
to use the brakes if necessary.
Select an appropriate speed while
driving in curves.
ACC may operate differently in a
sharp curve. It may reduce the
vehicle speed if the curve is too
sharp.
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, signs, guardrails, and other
stationary objects when entering or
exiting a curve. This is normal
operation. The vehicle does not
need service. Other Vehicle Lane Changes
ACC will not detect a vehicle ahead
until it is completely in the lane. The
brakes may need to be manually
applied.
Do Not Use ACC on Hills and
When Towing a Trailer