GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Introduction 3
Danger, Warning, and
Caution
Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{Danger
Danger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{Warning
Warning indicates a hazard that
could result in injury or death.
Caution
Caution indicates a hazard that
could result in property or vehicle
damage.
A circle with a slash through it is a
safety symbol which means“Do
not,” “Do not do this,” or“Do not let
this happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M: Shown when the owner ’s
manual has additional instructions
or information.
*: Shown when the service
manual has additional instructions
or information.
0: Shown when there is more
information on another page —
“see page.” Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. See the
features in this manual for
information.
u:
Air Conditioning System
G:Air Conditioning Refrigerant Oil
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
$:Brake System Warning Light
9:Dispose of Used Components
Properly
P: Do Not Apply High Pressure
Water
B: Engine Coolant Temperature
_: Flame/Fire Prohibited
H:Flammable
[:Forward Collision Alert
R: Fuse Block Cover Lock
Location
+: Fuses
j:ISOFIX/LATCH System Child
Restraints
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 9
Keys, Doors, and
Windows
Keys and Locks
Keys (Key Access) . . . . . . . . . . . . . . 9
Keys (Keyless Access) . . . . . . . . 12
Remote Keyless Entry (RKE)System . . . . . . . . . . . . . . . . . . . . . . . 13
Remote Keyless Entry (RKE) System Operation (Key
Access) . . . . . . . . . . . . . . . . . . . . . . 13
Remote Keyless Entry (RKE) System Operation (Keyless
Access) . . . . . . . . . . . . . . . . . . . . . . 16
Remote Vehicle Start . . . . . . . . . . 25
Door Locks . . . . . . . . . . . . . . . . . . . . 26
Power Door Locks . . . . . . . . . . . . . 27
Delayed Locking . . . . . . . . . . . . . . . 27
Automatic Door Locks . . . . . . . . . 27
Lockout Protection . . . . . . . . . . . . . 28
Safety Locks . . . . . . . . . . . . . . . . . . . 28
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . 29
Power Assist Steps . . . . . . . . . . . . 34
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . 36
Vehicle Alarm System . . . . . . . . . 36 Steering Column Lock . . . . . . . . . 37
Immobilizer . . . . . . . . . . . . . . . . . . . . 37
Immobilizer Operation . . . . . . . . . 37
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . 39
Manual Mirrors . . . . . . . . . . . . . . . . . 39
Trailer-Tow Mirrors . . . . . . . . . . . . . 40
Power Mirrors . . . . . . . . . . . . . . . . . . 41
Folding Mirrors . . . . . . . . . . . . . . . . . 42
Heated Mirrors . . . . . . . . . . . . . . . . . 43
Automatic Dimming Mirror . . . . . 43
Blind Spot Mirrors . . . . . . . . . . . . . . 43
Reverse Tilt Mirrors . . . . . . . . . . . . 44
Interior Mirrors
Interior Rearview Mirrors . . . . . . . 44
Manual Rearview Mirror . . . . . . . . 44
Automatic Dimming Rearview
Mirror . . . . . . . . . . . . . . . . . . . . . . . . . 44
Rear Camera Mirror . . . . . . . . . . . . 45
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . 47
Manual Windows . . . . . . . . . . . . . . 47
Power Windows . . . . . . . . . . . . . . . 47
Rear Windows . . . . . . . . . . . . . . . . . 49
Sun Visors . . . . . . . . . . . . . . . . . . . . . 50
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 50
Keys and Locks
Keys (Key Access)
{Warning
Leaving children in a vehicle with
the ignition key is dangerous and
children or others could be
seriously injured or killed. They
could operate the power windows
or other controls or make the
vehicle move. The windows will
function with the keys in the
ignition, and children or others
could be caught in the path of a
closing window. Do not leave
children in a vehicle with the
ignition key.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
12 Keys, Doors, and Windows
learned and all previously
known keys will no longer work
with the vehicle.
6. To learn a second key, turn the ignition off, insert the second
key to be learned, and turn the
ignition on.
After two keys are learned, the
remaining keys can be learned by
following the procedure in
“Programming with Two
Recognized Keys.”
The key has a bar-coded key tag
that the dealer or qualified locksmith
can use to make new keys. Store
this information in a safe place, not
in the vehicle.
See your dealer if a replacement
key or additional key is needed.
If it becomes difficult to turn a key,
inspect the key blade for debris.
Periodically clean with a brush
or pick.
If locked out of the vehicle, see
Roadside Assistance Program
0 466. With an active OnStar or connected
service plan, an OnStar Advisor
may remotely unlock the vehicle.
See
OnStar Overview 0476.
Keys (Keyless Access)
{Warning
Leaving children in a vehicle with
an ignition key or Remote
Keyless Entry (RKE) transmitter is
dangerous and children or others
could be seriously injured or
killed. They could operate the
power window or other controls or
make the vehicle move. The
windows will function with the key
in the ignition or with the RKE
transmitter in the vehicle, and
children or others could be caught
in the path of a closing window.
Do not leave children in a vehicle
with the ignition key or an RKE
transmitter.
If the vehicle has the Keyless
Access system, the transmitter has
a button on the side of the
transmitter used to remove the key.
This key is used for the driver door
and glove box.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
26 Keys, Doors, and Windows
The engine will continue to run
for 15 minutes. After
30 seconds, repeat
Steps 1 and 2 for a 15-minute
time extension.
Turn the ignition on to operate the
vehicle.
Extending Engine Run Time
The engine run time can be
extended by 15 minutes, for a total
of 30 minutes, if during the first
15 minutes Steps 1 and 2 are
repeated while the engine is still
running. An extension can be
requested 30 seconds after starting.
A maximum of two remote starts,
or a single start with an extension,
is allowed between ignition cycles.
The vehicle's ignition must be
turned on and then back off to use
remote start again.
Canceling a Remote Start
To cancel a remote start, do one of
the following:
. Press and hold
/until the
parking lamps turn off. .
Turn on the hazard warning
flashers.
. Turn the ignition on and then off.
Door Locks
{Warning
Unlocked doors can be
dangerous.
. Passengers, especially
children, can easily open
the doors and fall out of a
moving vehicle. The doors
can be unlocked and
opened while the vehicle is
moving. The chance of
being thrown out of the
vehicle in a crash is
increased if the doors are
not locked. So, all
passengers should wear
seat belts properly and the
doors should be locked
whenever the vehicle is
driven.
(Continued)
Warning (Continued)
.Young children who get into
unlocked vehicles may be
unable to get out. A child
can be overcome by
extreme heat and can suffer
permanent injuries or even
death from heat stroke.
Always lock the vehicle
whenever leaving it.
. Outsiders can easily enter
through an unlocked door
when you slow down or stop
the vehicle. Locking the
doors can help prevent this
from happening.
There are several ways to lock and
unlock the vehicle.
From outside:
. Use the Remote Keyless Entry
(RKE) transmitter.
. Use Keyless Access,
if equipped.
. Use the key in the driver door or
the passenger door, if equipped.
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
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
54 Seats and Restraints
The head restraint can be folded
forward to allow for better visibility
when the rear seat is unoccupied.
To fold the head restraint, press the
button on the side of the head
restraint.
When an occupant is in the seat,
always return the head restraint to
the upright position until it locks into
place. Push and pull on the head
restraint to make sure that it is
locked.
If you are installing a child restraint
in the rear seat, seeLower Anchors
and Tethers for Children (LATCH
System) 091. Center Headrest
The vehicle’s rear seat may be
equipped with a headrest in the
center seating position that cannot
be adjusted.
If you are installing a child restraint
in the rear seat, see
Lower Anchors
and Tethers for Children (LATCH
System) 091.
Front Seats
Seat Adjustment
{Warning
You can lose control of the
vehicle if you try to adjust a driver
seat while the vehicle is moving.
Adjust the driver seat only when
the vehicle is not moving.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Seats and Restraints 67
Always use the correct buckle for
your seating position.
Never route the lap or shoulder belt
over an armrest.
{Warning
The seat belt can be pinched if it
is routed under plastic trim on the
seat, such as trim around the rear
seatback folding handle or side
airbag. In a crash, pinched seat
belts might not be able to provide
adequate protection. Never allow
seat belts to be routed under
plastic trim pieces.
Lap-Shoulder Belt
All seating positions in the vehicle
have a lap-shoulder belt.
The following instructions explain
how to wear a lap-shoulder belt
properly.1. Adjust the seat, if the seat is adjustable, so you can sit up
straight. To see how, see
“Seats” in the Index.
2. Pick up the latch plate and pull
the belt across you. Do not let
it get twisted.
The lap-shoulder belt may lock
if you pull the belt across you
very quickly. If this happens, let
the belt go back slightly to
unlock it. Then pull the belt
across you more slowly.
If the shoulder portion of a
passenger belt is pulled out all
the way, the child restraint
locking feature may be
engaged. See Child Restraint
Systems 088. If this occurs, let
the belt go back all the way
and start again. If the locking