tailgate GMC SIERRA 2020 Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
6 Introduction
1. Tow/Haul Mode (On SomeModels). See Driver Mode
Control 0238
Automatic Transfer Case
Control (If Equipped).
See Four-Wheel Drive 0227
Driver Mode Control 0238 (If
Equipped).
2. Air Vents 0182.
3. Head-Up Display (HUD) 0152
(If Equipped).
4. Turn Signal Lever. See Turn
and Lane-Change Signals
0 170.
Windshield Wiper/Washer
0 120.
5. Instrument Cluster 0127.
6. Shift Lever. See Automatic
Transmission 0221.
Range Selection Mode. See
Manual Mode 0224.
7. Light Sensor. See Automatic
Headlamp System 0168.
8. Infotainment 0176.
9. Climate Control Systems 0177
(If Equipped). Dual Automatic Climate Control
System
0179 (If Equipped).
10. Heated and Ventilated Front
Seats 061 (If Equipped).
11.
XPark Assist Switch (If
Equipped). See Assistance
Systems for Parking or Backing
0 257.
gTraction Control/Electronic
Stability Control 0235.
|Hazard Warning Flashers
0 169.
ALane Keep Assist (LKA)
(1500 Series) 0278 (If
Equipped).
@Lane Departure Warning
(LDW) (2500/3500 Series)
0 276 (If Equipped).
5Hill Descent Control Switch
(If Equipped). See Hill Descent
Control (HDC) 0237.
jPower Assist Steps 036 (If
Equipped).
5Power Release Tailgate
(If Equipped). See Tailgate
0 28.
DC/AC Switch. See Power
Outlets 0122.
hAuto Stop Disable Switch
(If Equipped). See Stop/Start
System 0213.
LExpress Window Down
Button (If Equipped). See
Power Windows 049.
Tow/Haul Mode 0226 (On
Some Models).
12. Power Outlet (Alternating Current) (If Equipped). See
Power Outlets 0122.
13. Power Outlets 0122.
14. USB Port. See the infotainment manual.
15. Wireless Charging 0124 (If
Equipped).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
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) . . . . . . . . . . . . . . . . . . . . . . 15
Remote Vehicle Start . . . . . . . . . . 24
Door Locks . . . . . . . . . . . . . . . . . . . . 25
Power Door Locks . . . . . . . . . . . . . 26
Delayed Locking . . . . . . . . . . . . . . . 26
Automatic Door Locks . . . . . . . . . 26
Lockout Protection . . . . . . . . . . . . . 27
Safety Locks . . . . . . . . . . . . . . . . . . . 27
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . 28
Power Assist Steps . . . . . . . . . . . . 36
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . 37
Vehicle Alarm System . . . . . . . . . 37 Steering Column Lock . . . . . . . . . 38
Immobilizer . . . . . . . . . . . . . . . . . . . . 39
Immobilizer Operation . . . . . . . . . 39
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . 40
Manual Mirrors . . . . . . . . . . . . . . . . . 41
Trailer-Tow Mirrors . . . . . . . . . . . . . 41
Power Mirrors . . . . . . . . . . . . . . . . . . 43
Folding Mirrors . . . . . . . . . . . . . . . . . 43
Heated Mirrors . . . . . . . . . . . . . . . . . 44
Automatic Dimming Mirror . . . . . 44
Blind Spot Mirrors . . . . . . . . . . . . . . 44
Reverse Tilt Mirrors . . . . . . . . . . . . 45
Interior Mirrors
Interior Rearview Mirrors . . . . . . . 46
Manual Rearview Mirror . . . . . . . . 46
Automatic Dimming Rearview
Mirror . . . . . . . . . . . . . . . . . . . . . . . . . 46
Rear Camera Mirror . . . . . . . . . . . . 46
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . 48
Manual Windows . . . . . . . . . . . . . . 49
Power Windows . . . . . . . . . . . . . . . 49
Rear Windows . . . . . . . . . . . . . . . . . 51
Sun Visors . . . . . . . . . . . . . . . . . . . . . 51
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 51
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 - 4/4/19
14 Keys, Doors, and Windows
least four seconds. The engine may
be started from outside the vehicle
using the RKE transmitter. See
Remote Vehicle Start024.
Q:Press to lock all doors.
If enabled, the turn signal lamps
may flash and/or the horn may
sound on the second press to
indicate locking has occurred.
If enabled, the horn chirps when
Q
is pressed again within
three seconds. See Vehicle
Personalization 0157.
Pressing
Qarms the alarm system.
See Vehicle Alarm System 037.
If equipped with remote mirror
folding, pressing and holding
Qfor
one second will fold the mirrors,
if enabled. See Vehicle
Personalization 0157.
K:Press once to unlock only the
driver door. If
Kis pressed again
within three seconds, all remaining
doors unlock. The interior lamps may come on and stay on for
20 seconds or until the ignition is
turned on.
If enabled, the turn signal lamps
flash twice to indicate unlocking has
occurred. If enabled, the exterior
lamps may turn on. See
Vehicle
Personalization 0157.
Pressing
Kon the RKE transmitter
disarms the alarm system. See
Vehicle Alarm System 037.
If equipped with remote mirror
folding, pressing and holding
Kfor
one second will unfold the mirrors,
if enabled. See Vehicle
Personalization 0157.
Press and hold
Kto remotely open
the windows, if enabled. See
Vehicle Personalization 0157.
x:Press twice quickly to release
the tailgate, if equipped.
7: Press and release to initiate the
vehicle locator. The turn signal
lamps flash and the horn sounds
three times. Press and hold
7for more than
three seconds to activate the panic
alarm. The turn signal lamps flash
and the horn sounds repeatedly for
30 seconds. The alarm turns off
when the ignition is turned on or
7
is pressed again. The ignition must
be off for the panic alarm to work.
Programming Transmitters to
the Vehicle
Only RKE transmitters programmed
to this vehicle will work. If a
transmitter is lost or stolen, a
replacement can be purchased and
programmed through your dealer.
Each vehicle can have up to
eight transmitters programmed to it.
See your dealer for transmitter
programming.
Battery Replacement
Replace the battery in the
transmitter soon if the REPLACE
BATTERY IN REMOTE KEY
displays in the Driver Information
Center (DIC).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
16 Keys, Doors, and Windows
Remove the key by pressing the
button on the side of the RKE
transmitter near the bottom and pull
the key out. Never pull the key out
without pressing the button.
See your dealer if a new transmitter
is needed./:Press and releaseQ, then
immediately press and hold
/until
the turn signal lamps flash or for at
least four seconds. The engine may
be started from outside the vehicle
using the RKE transmitter. See
Remote Vehicle Start 024.
Q:Press to lock all doors and the
tailgate, if equipped.
If enabled, the turn signal lamps
flash and/or the horn may sound on
the second press to indicate locking
has occurred. If enabled, the horn chirps when
Qis pressed again
within three seconds. See Vehicle
Personalization 0157.
If the driver door is open when
Qis
pressed, all doors will lock and then
the driver door will immediately
unlock, if enabled. See Vehicle
Personalization 0157.
If the passenger door is open when
Qis pressed, all doors lock.
Pressing
Qarms the alarm system.
See Vehicle Alarm System 037.
If equipped with remote mirror
folding, pressing and holding
Qfor
one second will fold the mirrors,
if enabled. See Vehicle
Personalization 0157.
K:Press once to unlock only the
driver door. If
Kis pressed again
within three seconds, all remaining
doors and the tailgate unlock. The

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Keys, Doors, and Windows 17
interior lamps may come on and
stay on for 20 seconds or until the
ignition is turned on.
If enabled, the turn signal lamps
flash twice to indicate unlocking has
occurred. If enabled, the exterior
lamps may turn on. SeeVehicle
Personalization 0157.
Pressing
Kon the RKE transmitter
disarms the alarm system. See
Vehicle Alarm System 037.
If equipped with remote mirror
folding, pressing and holding
Kfor
one second will unfold the mirrors,
if enabled. See Vehicle
Personalization 0157.
Press and hold
Kuntil the windows
fully open, if remote window
operation is enabled. See Vehicle
Personalization 0157.
x:Press twice quickly to release
the tailgate, if equipped.
7: Press and release to initiate
vehicle locator. The turn signal
lamps flash and the horn sounds
three times.
Press and hold
7for more than
three seconds to activate the panic
alarm. The turn signal lamps flash
and the horn sounds repeatedly for
30 seconds. The alarm turns off
when the ignition is turned on or
7
is pressed again. The ignition must
be off for the panic alarm to work.
Keyless Access Operation
The Keyless Access system allows
for doors and the tailgate to be
accessed without pressing the RKE
transmitter button. The RKE
transmitter must be within 1 m (3 ft)
of the tailgate or door being opened.
If the vehicle has this feature, there
will be a button on the outside door
handles.
Keyless Access can be
programmed to unlock all doors on
the first lock/unlock press from the driver door. Keyless Unlocking can
also be turned off. See
Vehicle
Personalization 0157.
If equipped with memory seats, RKE
transmitters 1 and 2 are linked to
seating positions of memory 1 or 2.
See Memory Seats 059.
Keyless Unlocking/Locking from
the Driver Door
When the doors are locked and the
RKE transmitter is within 1 m (3 ft)
of the door handle, pressing the
lock/unlock button on the driver door
handle will unlock the driver door.
If the lock/unlock button is pressed
again within five seconds, all
passenger doors and the tailgate
will unlock.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
18 Keys, Doors, and Windows
Driver Side Shown, PassengerSide Similar
Pressing the lock/unlock button will
cause all doors to lock if any of the
following occur:
. It has been more than
five seconds since the first lock/
unlock button press.
. Two lock/unlock button presses
were used to unlock all doors.
. Any vehicle door has been
opened and all doors are now
closed. Keyless Unlocking/Locking from
the Passenger Doors
When the doors are locked and the
RKE transmitter is within 1 m (3 ft)
of the door handle, pressing the
lock/unlock button on a passenger
door handle will unlock all doors.
Pressing the lock/unlock button will
cause all doors to lock if any of the
following occur:
.
The lock/unlock button was used
to unlock all doors.
. Any vehicle door has been
opened and all doors are now
closed.
Disable/Enable Keyless Unlocking
of Exterior Door Handles and
Tailgate
If equipped, keyless unlocking of the
exterior door handles and tailgate
can be disabled and enabled.
Disabling Keyless Unlocking:
With the vehicle off, press and hold
QandKon the RKE transmitter at
the same time for approximately
three seconds. The turn signal
lamps will flash four times quickly to indicate access is disabled. Using
any exterior handle to unlock the
doors or open the tailgate will cause
the turn signal lamps to flash four
times quickly, indicating access is
disabled. If disabled, disarm the
alarm system before starting the
vehicle.
Enabling Keyless Unlocking:
With the vehicle off, press and hold
QandKon the RKE transmitter at
the same time for approximately
three seconds. The turn signal
lamps will flash twice quickly to
indicate access is enabled.
Passive Locking
This feature will lock the vehicle
several seconds after all doors are
closed, if the vehicle is off and at
least one RKE transmitter has been
removed from the interior, or none
remain in the interior.
If other electronic devices interfere
with the RKE transmitter signal, the
vehicle may not detect the RKE
transmitter inside the vehicle.
If passive locking is enabled, the
doors may lock with the RKE

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
28 Keys, Doors, and Windows
1. Unlock the door and open itfrom 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 - 4/4/19
Keys, Doors, and Windows 29
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 15.
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.
Power 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 - 4/4/19
30 Keys, Doors, and Windows
Caution
To avoid damage to the tailgate,
make sure the area behind the
tailgate is clear before opening it.
If equipped with a power open/close
tailgate, the tailgate can be opened
or closed in several ways. To open
the tailgate, do one of the following:
. Press
xtwice quickly on the
RKE transmitter until the tailgate
moves. See Remote Keyless
Entry (RKE) System Operation
(Key Access) 013 or
Remote Keyless Entry (RKE)
System Operation (Keyless
Access) 015. If equipped with
Keyless Access, a locked
tailgate can be opened if the
RKE transmitter is within
1 m (3 ft).. Press5on the center stack.
.
Press the touch pad on the
tailgate handle after unlocking all
doors.
To close the tailgate, do one of the
following:
. Press
xon the RKE
transmitter once, then quickly
press and hold
xuntil the
tailgate completely closes. If
x
is released prior to it being fully
closed, the tailgate will reopen.
. Press and hold
5on the
center stack until the tailgate is
fully closed. If
5is released
prior to the tailgate being fully
closed, it will reopen. A chime
will sound when the tailgate is
fully closed.
. Press the touch pad on the
tailgate handle.
A chime sounds and the taillamps
flash during the closing operation.
If the warning chime is not
functioning, the tailgate will not

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Keys, Doors, and Windows 31
power close. Power opening is still
enabled. See your dealer for
service.
The power tailgate may be
temporarily disabled after repeated
power cycling over a short period of
time. If this occurs, the tailgate can
still be operated manually.
The vehicle must be in P (Park) to
operate the power tailgate. If the
vehicle is shifted out of P (Park)
while the power function is in
progress, the tailgate will continue
to completion. If the vehicle is
accelerated while the tailgate is still
closing, the tailgate may stop and
reverse direction. Make sure the
tailgate is closed and latched before
driving.Lift-to-Close Operation
To close the tailgate using the
lift-to-close feature, lift the tailgate
from the full-open position to at least
10 cm (4 in) and hold it momentarily.
Then, the tailgate will start closing
automatically. If the tailgate is lifted
more than halfway between open
and close, then it will not close
automatically.
Obstacle Detection
If the tailgate encounters an
obstacle during a power open cycle,
it will stop on the obstacle. After
removing the obstruction, the
tailgate can be allowed to open.If the tailgate encounters an
obstacle during the closing cycle, it
will stop and reverse to full open.
If the tailgate encounters multiple
obstacles, the power function will
deactivate. After removing the
obstructions, manually close the
tailgate to resume normal power
operation.
Manual Operation
The tailgate can be manually closed
from the full-open position when the
tailgate is lifted in a continuous
motion. If the tailgate motion is
stopped between the full-open and
half-closed positions, the lift-to-close
feature can engage and power
close the tailgate. If the touch pad is
pressed during power operation, the
tailgate will stop and allow manual
operation. The tailgate must be held
after stopping, or it will continue
to open.