lock GMC SIERRA 2021 Owner's Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 29
.To close the tailgate step, lift it firmly.
Make sure that both side latches are
engaged.
Do not place a load on top of the step when
using it as a load stop.Using the Assist Handle
The assist handle helps with entering the
pickup box. To use:
1. Lift up on the handle until it locks in the open position.
2. To return the assist handle, pull the release lever toward the ball end of the
handle and push the handle back to the
closed position.
Applying Loads to Tailgates
Caution
Do not put ramp loads on the inner
tailgate alone. Damage to the inner
tailgate may occur.
Preferred Method
Alternate Method

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
30 Keys, Doors, and Windows
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 same side to complete the motion.
If the obstruction is not cleared, the assist
steps remain extended.
Slight movement of the steps while
extended is normal.
Kick Switch
1. Place the vehicle in P (Park) and unlock
the doors. 2. Kick the switch to extend the power
assist step to the tire. A Driver
Information Center (DIC) message
displays.
3. Kick the switch again to return to normal operation.
Center Stack Switch
The power assist steps can be extended to
the tire by pressing
j. When extending
the steps with
j, the kick switch is
disabled. The vehicle must be in P (Park) or
N (Neutral).

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 31
To extend the steps:
.Pressjto extend both steps. A DIC
message displays.
.Pressjagain to extend to the tire.
A DIC message displays.
.Pressjagain to return to normal
operation.
Enable/Disable
To enable or disable the power assist steps,
press and hold
jfor four seconds. A DIC
message displays.
Cleaning
Clean the power assist steps regularly. For
an automatic car wash, extend the steps
while in N (Neutral) using the center stack
switch. The steps will stow when shifting
into D (Drive).
Vehicle Security
This vehicle has theft-deterrent features;
however, they do not make the vehicle
impossible to steal.
Vehicle Alarm System
The indicator light, on the instrument panel
near the windshield, indicates the status of
the system.
Off : Alarm system is disarmed.
On Solid : Vehicle is secured during the
delay to arm the system.
Fast Flash : Vehicle is unsecured. A door or
the hood is open.
Slow Flash : Alarm system is armed.
Arming the Alarm System
1. Turn off the vehicle. 2. Lock the vehicle in one of two ways:
.Use the RKE transmitter.
.With a door open, pressQon the
interior of the door.
3. After 30 seconds, the alarm system will arm and the indicator light will begin to
slowly flash. Pressing
Qon the RKE
transmitter a second time will bypass
the 30-second delay and immediately
arm the alarm system.
The vehicle alarm system will not arm if the
doors are locked with the key.
If the driver door is opened without first
unlocking with the RKE transmitter, the horn
will chirp and the lights will flash to indicate
pre-alarm. If the vehicle is not started,
or the door is not unlocked by pressing
K
on the RKE transmitter during the 10-second
pre-alarm, the alarm will be activated.
The alarm will also be activated if a
passenger door or the hood is opened
without first disarming the system. When
the alarm is activated, the turn signals flash
and the horn sounds for about 30 seconds.
The alarm system will then re-arm to
monitor for the next unauthorized event.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
32 Keys, Doors, and Windows
Disarming the Alarm System
To disarm the alarm system or turn off the
alarm if it has been activated:
.PressKon the RKE transmitter.
.Start the vehicle.
To avoid setting off the alarm by mistake:
.Lock the vehicle after all occupants have
exited.
.Always unlock a door with the RKE
transmitter.
Unlocking the driver door with the key
will not disarm the system or turn off the
alarm.
How to Detect a Tamper Condition
IfKis pressed on the RKE transmitter and
the horn chirps three times, an alarm
occurred previously while the alarm system
was armed.
If the alarm has been activated, a message
will appear on the DIC.
Steering Column Lock
If equipped, the steering column lock is a
theft-deterrent device. This feature locks the
steering column when the vehicle is turned
off and the driver door is opened, or when the driver door is opened and then the
vehicle is turned off. The steering column
unlocks when the vehicle is turned on.
The Driver Information Center (DIC) may
display one of these messages:
.A message to service the steering column
lock indicates that an issue has been
detected with the column lock feature
and the vehicle should be serviced.
.A message that the steering column is
locked indicates that the engine is
running, but the steering column is still
locked. It is normal for the column to be
locked during a remote start, but the
column should unlock after the brake
pedal is pressed and the vehicle is started.
No message will display during a remote
start.
.A message that the steering wheel must
be turned and the vehicle must be started
again indicates that the column lock
mechanism is bound, the column locking
device was unable to unlock the steering
column, and the vehicle did not start.
If this happens, immediately turn the
steering wheel from side to side to
unbind the column lock. If this does not
unlock the steering column, turn the
vehicle off and open the driver door to
reset the system. Then turn the vehicle
on and immediately turn the steering
wheel side to side for about 15 seconds.
In some cases, it may take significant
force to unbind the column.
To keep the steering column from binding,
straighten the front wheels before turning
off the vehicle.
Immobilizer
See Radio Frequency Statement 0436.
Immobilizer Operation
This vehicle has a passive theft-deterrent
system.
The system does not have to be manually
armed or disarmed.
The vehicle is automatically immobilized
when the vehicle is turned off.
The system is automatically disarmed when
the ignition is turned from off to on.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
40 Keys, Doors, and Windows
{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.
.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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 41
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 prevent operation of
the windows. SeeKeys (Key Access)07
or
Keys (Keyless Access) 09.
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) 0236.
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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
42 Keys, Doors, and Windows
Press2to 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. 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
0 131.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 43
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. SeeRetained
Accessory Power (RAP) 0236.
.Press the switch to open the window.
.Pull the switch to close the window.
The power sliding rear window cannot be
operated manually.
Sun Visors
Pull the sun visor down to block glare.
If equipped, detach the sun visor from the
center mount to pivot to the side window
or to extend along the rod.
If equipped, there is a lighted mirror on the
sun visor. Lift the cover to open.
Roof
Sunroof
1. SLIDE Switch
2. TILT Switch
If equipped, the sunroof operates when the
ignition is on or in ACC/ACCESSORY, or when
Retained Accessory Power (RAP) is active.
See Retained Accessory Power (RAP) 0236.
Slide Switch
Express-Open/Express-Close : To
express-open the sunroof, fully press and
release
I(1). Press and releaseI(1) again
to stop the movement. To express-close the

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
44 Keys, Doors, and Windows
sunroof, fully press and releaseK(1).
Press and release
K(1) again to stop the
movement.
Open/Close (Manual Mode) : To open the
sunroof, press and hold
I(1). ReleaseI(1)
to stop the movement. Press and
hold
K(1) to close the sunroof.
Release
K(1) to stop the movement.
Tilt Switch
Vent : From the closed position, press
J(2)
to vent the sunroof. Press
K(2) to close
the vent.
When the sunroof is opened, an air deflector
will automatically raise. The air deflector will
retract when the sunroof is closed.
The sunroof also has a sunshade, which can
be pulled forward to block sun rays. The
sunshade must be opened and closed
manually.
Automatic Reversal System
The sunroof has an automatic reversal
system that is only active when the sunroof
is operated in express-close mode.
If an object is in the path while
express-closing, the reversal system will
detect an object, stop, and open the sunroof
slightly.
If frost or other conditions prevent closing,
override the feature by closing the sunroof
in manual mode. To stop movement, release
K(1).
Dirt and debris may collect on the sunroof
seal or in the track. This could cause an
issue with sunroof operation or noise. It could also plug the water drainage
system. Periodically open the sunroof and
remove any obstacles or loose debris. Wipe
the sunroof seal and roof sealing area using
a clean cloth, mild soap, and water. Do not
remove grease from the sunroof tracks.
If water is seen dripping into the water
drainage system, this is normal.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
46 Seats and Restraints
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.
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, see
Lower Anchors and Tethers for
Children (LATCH System) 077.
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) 077.
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.