warning GMC SIERRA DENALI 2020 User Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 29
To open a rear door when the safety
lock is on:1. Unlock the door by activating the inside handle, by pressing
the power door unlock switch,
or by using the Remote
Keyless Entry (RKE)
transmitter.
2. Open the door from the outside.
When the safety lock is enabled,
adults and older children will not be
able to open the rear door from the
inside. Cancel the safety locks to
enable the doors to open from the
inside.
To cancel the safety lock: 1. Unlock the door and open it from the outside.
2. Move the lever up to unlock. Do the same for the other door.Doors
Tailgate
Manual Tailgate
{Warning
It is extremely dangerous to ride
on the tailgate, even when the
vehicle is operated at low speeds.
People riding on the tailgate can
easily lose their balance and fall
in response to vehicle
maneuvers. Falling from a moving
vehicle may result in serious
injuries or death. Do not allow
people to ride on the tailgate. Be
sure everyone in your vehicle is in
a seat and using a seat belt
properly.
Use the key to unlock the tailgate.
Open the tailgate by lifting up on its
handle while pulling the
tailgate down.
To shut the tailgate, firmly push it
upward until it latches. After closing the tailgate, pull it back
to be sure it is latched securely.
Some tailgates have an electric
latch. If the battery is disconnected
or has low voltage, the tailgate will
not open. The tailgate will resume
operation when the battery is
reconnected or recharged.Power Release Tailgate
{Warning
Make sure there is no one in the
way of the power tailgate as it is
opening and closing, and keep
hands away from the tailgate
hinges when in use. You or others
could be injured if caught in the
path of the power tailgate or
tailgate hinges.
Caution
To avoid damage to the tailgate,
make sure the area behind the
tailgate is clear before opening it.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
30 Keys, Doors, and Windows
In the case of a dead battery, the
tailgate can be opened manually.
Contact your dealer or Roadside
Assistance.
If equipped, to lock or unlock the
tailgate, use the RKE transmitter or
the key. SeeRemote Keyless Entry
(RKE) System Operation (Key
Access) 013 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 16.
The vehicle must be in P (Park).
To open the tailgate:
. Press
xtwice quickly on the
RKE transmitter until the tailgate
moves.
. Press5on the center stack.
.
Press the touch pad on the
tailgate handle after unlocking all
doors. Use the top of the tailgate
to pull against if assistance is
required. If equipped with
Keyless Access, a locked
tailgate can be opened if the
RKE transmitter is within
1 m (3 ft).
To close the tailgate, firmly push it
upward until it latches. Pull it back
to be sure it is latched securely.
MultiPro Tailgate
{Warning
Make sure there is no one in the
way of the power tailgate as it is
opening and closing, and keep
hands away from the tailgate
hinges when in use. You or others
could be injured if caught in the
path of the power tailgate or
tailgate hinges.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
32 Keys, Doors, and Windows
To open the inner tailgate, press the
upper touch pad on the tailgate
handle after unlocking all doors. Pull
the top of the tailgate to open.
Caution
Do not open the inner tailgate
with the primary tailgate open if
there is a hitch ball or trailer
attached. This may damage the
tailgate.
To close the inner tailgate with the
primary tailgate closed, firmly push
or pull it upward until it latches. Pull
it back to be sure it is latched
securely.
To close the inner tailgate with the
primary tailgate open:
. Hold the primary tailgate and
firmly close the inner tailgate.
. Raise the inner tailgate so it
meets the primary tailgate and
close together at the same time.
When using the tailgate step as a
load stop, the load must be secured
as the load could shift. See Cargo
Tie-Downs 0115.
Tailgate Step
{Warning
To avoid personal injury, keep
hands away from the hinges
when operating the tailgate step.
With the primary and inner tailgates
open, the tailgate step can be
lowered to access the pickup bed.
Using the Step
Caution
When using the tailgate as a step,
the load rating is 170 kg (375 lb),
which includes a person and
cargo. Overloading the tailgate
step can cause damage to the
tailgate system.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
34 Keys, Doors, and Windows
Preferred MethodAlternate Method
When applying any load to the
tailgate, distribute the weight evenly
across the width of the tailgate. This
applies to all tailgate types.
. Use a load-distributing
member (1).
. Secure the ramp to the
bumper (2).
Power Assist Steps
{Warning
To avoid personal injury or
property damage, before entering
or exiting the vehicle, be sure the
power assist step is fully
extended. Do not step on the
power assist step while it is
moving. Never place hands or
other body parts between the
extended power assist step and
the vehicle.
If equipped, the power assist steps,
when enabled, will extend when the
door is opened. They will retract
three seconds after the door is
closed or immediately if the vehicle
starts moving.
Keep hands, children, pets, objects,
and clothing clear of the power
assist steps when in motion.
The steps will reverse direction if
there is an obstruction. If possible,
carefully remove the obstruction,
then open and close the door on the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 39
service. If the vehicle does start, the
first key may be faulty. See your
dealer. It is possible for the
immobilizer system to learn new or
replacement keys. Up to eight keys
can be programmed for the vehicle.
To program additional keys, see
Keys (Key Access)09or
Keys (Keyless Access) 012. Do not
leave the key or device that disarms
or deactivates the vehicle theft
system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system.Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
Standard Mirrors
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat. Trailer-Tow Mirrors
The upper portion of both the driver
and passenger mirrors is flat.
The lower portion of both the driver
and passenger mirrors is convex.
A convex mirror
’s surface is curved
so more can be seen from the driver
seat. The lower portion is adjusted
manually.
Manual Mirrors
If equipped, adjust manual mirrors
by moving the mirror up and down
or left to right to see a little of the
side of the vehicle and to have a
clear view behind the vehicle.
Using hood-mounted air deflectors
and add-on convex mirror
attachments could decrease mirror
performance.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
46 Keys, Doors, and Windows
.Tilt
{Warning
The Rear Camera Mirror (RCM)
has a limited view. Portions of the
road, vehicles, and other objects
may not be seen. Do not drive or
park the vehicle using only this
camera. Objects may appear
closer than they are. Check the
outside mirrors or glance over
your shoulder when making lane
changes or merging. Failure to
use proper care may result in
injury, death, or vehicle damage. Troubleshooting
See your dealer for service if a blue
screen and
3are displayed in
the mirror, and the display shuts off.
Also, push the tab as indicated to
return to the automatic
dimming mode.
The Rear Camera Mirror may not
work properly or display a clear
image if:
. There is glare from the sun or
headlamps. This may obstruct
objects from view. If needed,
push the tab to turn off the
display.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 47
.Dirt, snow, or other debris blocks
the camera lens. Clean the lens
with a soft damp cloth.
. The camera’s mounting on the
vehicle has been damaged, and/
or the position or the mounting
angle of the camera has
changed.Windows
{Warning
Never leave a child, a helpless
adult, or a pet alone in a vehicle,
especially with the windows
closed in warm or hot weather.
They can be overcome by the
extreme heat and suffer
permanent injuries or even death
from heat stroke.
The vehicle aerodynamics are
designed to improve fuel economy
performance. This may result in a
pulsing sound when either rear
window is down and the front
windows are up. To reduce the
sound, open either a front window
or the sunroof, if equipped.
Manual Windows
If equipped, turn the hand crank on
each door to manually raise or lower
the manual windows.
Power Windows
{Warning
Children could be seriously
injured or killed if caught in the
path of a closing window. Never
leave the Remote Keyless Entry
(RKE) transmitter or keys in a
vehicle with children. When there
are children in the rear seat, use
the window lockout button to
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
48 Keys, Doors, and Windows
Warning (Continued)
prevent operation of the windows.
SeeKeys (Key Access) 09or
Keys (Keyless Access) 012.
The power windows work when the
ignition is on, in ACC/ACCESSORY,
or when Retained Accessory Power
(RAP) is active. See Retained
Accessory Power (RAP) 0216.
Using the window switch, press to
open or pull to close the window. The windows may be temporarily
disabled if they are used repeatedly
within a short time.
Window Lockout
With Power Folding Mirrors,
Without Similar
This feature stops the rear door
passenger window switches from
working except from the driver
position.
Press
2to engage the rear
window lockout feature. The
indicator light is on when engaged.
Press
2again to disengage.
Windows Express Movement
All windows can be opened without
holding the window switch. Press
the switch down fully and quickly
release to express open the
window.
If equipped, pull the window switch
up fully and quickly release to
express close the window.
Briefly press or pull the window
switch in the same direction to stop
that window’s express movement.
Express Window Down
L: If equipped, this button will be
on the center stack.
Press and hold
Lto open all
windows. Release
Lto stop all
movement.
Use the power window switches to
close each window.
Window Automatic Reversal
System
The express-close feature will
reverse window movement if it
comes in contact with an object.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 49
Extreme cold or ice could cause the
window to auto-reverse. The
window will operate normally after
the object or condition is removed.
Automatic Reversal System
Override
{Warning
If automatic reversal system
override is active, the window will
not reverse automatically. You or
others could be injured and the
window could be damaged.
Before using automatic reversal
system override, make sure that
all people and obstructions are
clear of the window path.
When the engine is on, override the
automatic reversal system by pulling
and holding the window switch if
conditions prevent it from closing.
Programming the Power
Windows
Programming may be necessary if
the vehicle battery has been
disconnected or discharged. If the
window is unable to express-up,
program each express-close
window: 1. Close all doors.
2. Turn the ignition on or to ACC/ ACCESSORY.
3. Partially open the window to be programmed. Then close it and
continue to pull the switch
briefly after the window has
fully closed.
4. Open the window and continue to press the switch briefly after
the window has fully opened.
Remote Window Operation
If equipped, this feature allows the
windows to be opened remotely.
If enabled in vehicle personalization,
press and hold
Kon the RKE
transmitter. See Vehicle
Personalization 0156.
Rear Windows
Power Sliding Rear Window
If equipped, the power sliding rear
window works when the ignition has
been turned on or to ACC/
ACCESSORY, or Retained
Accessory Power (RAP) must be
active. See Retained Accessory
Power (RAP) 0216.
. Press the switch to open the
window.
. Pull the switch to close the
window.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Seats and Restraints 53
Head Restraints
{Warning
With head restraints that are not
installed and adjusted properly,
there is a greater chance that
occupants will suffer a neck/
spinal injury in a crash. Do not
drive until the head restraints for
all occupants are installed and
adjusted properly.
Front Seats
The vehicle's front seats have
adjustable head restraints in the
outboard seating positions.
Adjust the head restraint so that the
top of the restraint is at the same
height as the top of the occupant's
head. This position reduces the
chance of a neck injury in a crash.To raise or lower the head restraint,
press the button on the side of the
head restraint and pull up or push
the head restraint down and release
the button.
Pull and push on the head restraint
after the button is released to make
sure that it is locked in place.
The front seat outboard head
restraints are not removable.
Rear Head Restraints
The vehicle’s rear seat has head
restraints in the outboard seating
positions that cannot be adjusted.