2021 GMC SIERRA Side mirror operation

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
14 Keys, Doors, and Windows
If the driver door is open whenQis
pressed, all doors will lock and then the
driver door will immediately unlock,
if enabled. See Vehicle Personalization 0131.
If the passenger door is open when
Qis
pressed, all doors lock.
Pressing
Qarms the alarm system. See
Vehicle Alarm System 031.
If equipped with remote mirror folding,
pressing and holding
Qfor one second will
fold the mirrors, if enabled. See Vehicle
Personalization 0131.
K:Press once to unlock only the driver
door. If
Kis pressed again within
three seconds, all remaining doors and the
tailgate 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 0131.
Pressing
Kon the RKE transmitter disarms
the alarm system. See Vehicle Alarm System
0 31. If equipped with remote mirror folding,
pressing and holding
Kfor one second will
unfold the mirrors, if enabled. See Vehicle
Personalization 0131.
Press and hold
Kuntil the windows fully
open, if remote window operation is
enabled. See Vehicle Personalization 0131.
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
7is 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 0131.
If equipped with memory seats, RKE
transmitters 1 and 2 are linked to seating
positions of memory 1 or 2. See Memory
Seats 049.
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 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 33
The security light, in the instrument cluster,
comes on if there is a problem with arming
or disarming the theft-deterrent system.
The system has one or more RKE
transmitters matched to an immobilizer
control unit in your vehicle. Only a correctly
matched RKE transmitter will start the
vehicle. If the transmitter is ever damaged,
you may not be able to start your vehicle.
When trying to start the vehicle, the
security light may come on briefly when the
ignition is turned on. If the engine does not
start and the security light stays on, there is
a problem with the system. Turn the
ignition off and try again.
If the vehicle will not change ignition modes
(ACC/ACCESSORY, on, off), and the RKE
transmitter appears to be undamaged, try
another transmitter. Or, you may try placing
the transmitter in the transmitter pocket
located in the center console. SeeRemote
Keyless Entry (RKE) System Operation (Key
Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013.
If the ignition mode will not change with
the other transmitter or with the
transmitter in the transmitter pocket, your
vehicle needs service. If the ignition does change modes, the first transmitter may be
faulty. See your dealer who can service the
theft-deterrent system and have a new RKE
transmitter programmed to the vehicle.
It is possible for the immobilizer system to
learn new or replacement RKE transmitters.
Up to eight transmitters can be
programmed for the vehicle. To program
additional transmitters, see "Programming
Transmitters to the Vehicle" under
Remote
Keyless Entry (RKE) System Operation (Key
Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013
Do not leave the transmitter or device that
disarms or deactivates the vehicle theft
system in the vehicle.
When equipped with a key, if the engine
still does not start, and the key appears to
be undamaged, try another ignition key.
It may be necessary to check the fuse. See
Fuses and Circuit Breakers 0353. If the
engine still does not start with the other
key, the vehicle needs 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)07or
Keys (Keyless Access) 09. 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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 35
To return the mirror to its original position,
reverse the motion.
Power Extend :If equipped, press the power
extend button to fully extend the mirror.
Press again to retract.
Resetting the Power Extend Mirrors
Reset the power extend mirrors if:
.The mirrors are accidentally obstructed
while extending/retracting.
.The mirrors are accidentally manually
extended/retracted.
.The mirrors vibrate at normal driving
speeds. If a popping noise from the mirror is heard,
this sound is normal as the manual detents
are aligning after a manual extend/retract
operation has occurred.
Auxiliary Cargo Mirror Lamps
If equipped, cargo mirror lamps face
rearward to provide more light on the sides
of the vehicle, if needed. See
Exterior Cargo
Lamps 0144.
Advanced Trailering Vision System Side
Cameras
If equipped, the Advanced Trailering Vision
System side cameras are on the bottom of
the outside mirrors. See “Surround Vision
(360 Degrees)” underAssistance Systems for
Parking or Backing 0266.
Power Mirrors
To adjust each mirror:
1. Press
jor|to select the driver or
passenger side mirror. The indicator light
will illuminate.
2. Press the arrows on the control pad to move the mirror in the desired direction.
3. Adjust each outside mirror so that a little of the vehicle and the area behind it can
be seen.
4. Press
jor|again to deselect the
mirror.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
36 Keys, Doors, and Windows
Turn Signal Indicator
If equipped, the mirror has turn signal
indicator lights, which flash in the direction
of the turn or lane change.
Task Lighting
If equipped, task lighting projects light from
the outside mirrors to the sides of the
vehicle. SeeTask Lighting 0144.
Puddle Lamps
If equipped, puddle lamps project light from
the bottom of the mirror to the area of
ground below the driver and passenger
doors. See Entry Lighting 0146 and
Exit Lighting 0146.
Memory Mirrors
The vehicle may have memory mirrors. See
Memory Seats 049.
Lane Change Alert (LCA)
The vehicle may have LCA. See Lane Change
Alert (LCA) 0280.Folding Mirrors
Manual Folding Mirrors
If equipped, push the mirror toward the
vehicle to fold. Push the mirror outward to
return to its original position.
Manually fold the mirrors inward to prevent
damage when going through an automatic
car wash.
Power Folding Mirrors
If equipped, pressgto power fold the
mirrors. Press again to unfold. Resetting the Power Folding Mirrors
Reset the power folding mirrors if:
.The mirrors are accidentally obstructed
while folding.
.The mirrors are accidentally manually
folded/unfolded.
.The mirrors will not stay in the unfolded
position.
.The mirrors vibrate at normal driving
speeds.
Fold and unfold the mirrors one time using
the mirror controls to reset them to their
normal position. A noise may be heard
during the resetting of the power folding
mirrors. This sound is normal after a manual
folding operation.
Remote Mirror Folding
If equipped, press and holdQon the RKE
transmitter for approximately one second to
remotely fold the exterior mirrors. Press and
hold
Kon the RKE transmitter for
approximately one second to unfold. See
Remote Keyless Entry (RKE) System
Operation (Key Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 51
Save preferred memory feature positions to
both 1 and 2 if you are the only driver.
Manually Recalling Memory Positions
Press and hold 1, 2, or
Bto recall the
previously saved memory positions if you
are driver 1 or 2 identified in the DIC
welcome message.
To stop Manual Memory recall movement,
release 1, 2, or
Bor press any of the
following controls:
.Power seat
.Memory SET
.Power mirror, with the driver or
passenger side mirror selected
Manual Memory recall movement for 1, 2,
or
Bbuttons may be initiated and may
complete to the saved memory position if
the vehicle is in or out of P (Park).
Seat Entry Memory
The vehicle identifies the number of the
current driver’s RKE transmitter (1–8). See
Remote Keyless Entry (RKE) System
Operation (Key Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013. If the RKE
transmitter is 1 or 2, and Seat Entry Memory
is enabled in vehicle personalization, the positions saved to the same memory button
number 1 or 2 are automatically recalled
when the vehicle is turned on, or turned
from off to ACC/ACCESSORY. RKE
transmitters 3–8 will not provide automatic
memory recalls.
To turn Seat Entry Memory on or off, see
“Vehicle Personalization Settings”
previously
in this section and Vehicle Personalization
0 131.
The shift lever must be in P (Park) to start
Seat Entry Memory. Seat Entry Memory
recall will complete if the vehicle is shifted
out of P (Park) prior to reaching the saved
memory position.
To stop Seat Entry Memory recall
movement, turn the vehicle off or press any
of the following controls:
.Power seat
.Memory SET, 1, 2, orB
.Power mirror, with the driver or
passenger side mirror selected
If the saved memory seat position does not
automatically recall or recalls to the wrong
positions, the driver’s RKE transmitter
number (1 or 2) may not match the memory
button number that positions were saved to. Try storing the position to the other
memory button or try the other RKE
transmitter.
Seat Exit Memory
Seat Exit Memory is not linked to an RKE
transmitter. The position saved to
Bis
used for all drivers. To turn Seat Exit
Memory on or off, see "Vehicle
Personalization Settings" previously in this
section and Vehicle Personalization 0131.
If turned on, the position saved to
Bis
automatically recalled when one of the
following occurs:
.The vehicle is turned off and the driver
door is opened within a short time.
.The vehicle is turned off with the driver
door open.
To stop Seat Exit Memory movement, press
any of the following memory controls:
.Power seat
.Memory SET, 1, 2, orB
.Power mirror, with the driver or
passenger side mirror selected

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Instruments and Controls 133
Touch the controls on the infotainment
display to adjust the volume.
Reverse Tilt Mirror
When on, the driver, passenger, or both
driver and passenger outside mirrors will tilt
downward when the vehicle is shifted into
R (Reverse) to improve visibility of the
ground near the rear wheels. They may
move from their tilted position when the
vehicle is shifted out of R (Reverse) or
turned off. SeeReverse Tilt Mirrors 038.
Touch Off, On - Driver and Passenger, On -
Driver, or On - Passenger.
Remote Mirror Folding
When on, the outside mirrors will remotely
fold or unfold when the Remote Keyless
Entry (RKE) transmitter
QorKbutton is
pressed and held. See Folding Mirrors036.
Touch Off or On.
Lighting
Touch and the following may display:
.Vehicle Locator Lights
.Exit Lighting
.Automatic High Beam Assist Vehicle Locator Lights
This setting flashes the vehicle’s headlamps
when
Kis pressed on the Remote Keyless
Entry (RKE) transmitter.
Touch Off or On.
Exit Lighting
This setting specifies how long the
headlamps stay on after the vehicle is
turned off and exited.
Touch Off, 30 Seconds, 60 Seconds,
or 120 Seconds.
Automatic High Beam Assist
This setting specifies how the high beams
adjust based on the vehicle environment.
Touch IntelliBeam or Adaptive Headlight
System.
Power Door Locks
Touch and the following may display:
.Open Door Anti Lock Out
.Auto Door Unlock
.Delayed Door Lock Open Door Anti Lock Out
This setting prevents the driver door from
locking when the door is open. If this
setting is on, the Delayed Door Lock menu
will not be available.
Touch Off or On.
Auto Door Unlock
This setting allows selection of which doors
will automatically unlock when the vehicle is
shifted into P (Park).
Touch Off, All Doors, or Driver Door.
Delayed Door Lock
When on, this feature will delay the locking
of the doors. To override the delay, press
the power door lock switch on the door.
Touch Off or On.
Remote Lock, Unlock, and Start
Touch and the following may display:
.Remote Unlock Light Feedback
.Remote Lock Feedback
.Remote Door Unlock
.Remote Start Auto Cool Seats
.Remote Start Auto Heat Seats
.Remote Window Operation

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
208 Climate Controls
Changing the mode cancels the automatic
operation and the system goes into manual
mode. Press AUTO to return to automatic
operation.
To change the current mode, select one or
more of the following:
z:Air is directed to the windshield,
outboard a/c outlets, and side window
outlets.
Y: Air is directed to the a/c outlets.
[:Air is directed to the floor outlets,
with some air directed to the windshield,
outboard a/c outlets, and side window
outlets.
0MAX : Air is directed to the windshield
and the fan runs at a higher speed if not
already above a medium fan speed. This
mode overrides the previous mode selected
and clears fog or frost from the windshield
more quickly. When the control is pressed
again, the system returns to the previous
mode setting and fan speed.
For best results, clear all snow and ice from
the windshield before defrosting.
@: Press to turn on recirculation. An
indicator light comes on. Air is recirculated
to quickly cool the inside of the vehicle.
It can also be used to help reduce outside
air and odors that enter the vehicle.
Avoid using recirculation for long periods of
time in cold or damp conditions. Using
recirculation in cold or damp conditions can
result in window fogging.
A/C : Press to turn the air conditioning on
or off. An indicator light comes on to show
that the air conditioning is enabled. If the
fan is turned off, the air conditioner will not
run. The A/C light will stay on even if the
outside temperatures are below freezing.
Rear Window Defogger
1REAR : If equipped, press to turn the
rear window defogger on or off. An indicator
light on the button comes on to show that
the rear window defogger is on.
The rear window defogger only works when
the engine is running. The defogger turns
off if the ignition is turned off or to ACC/
ACCESSORY.
If equipped with heated outside mirrors,
press
fto turn them on or off. See Heated
Mirrors 037.
Caution
Using a razor blade or sharp object to
clear the inside rear window can damage
the rear window defogger. Repairs would
not be covered by the vehicle warranty.
Do not clear the inside rear window with
sharp objects.
Remote Start Climate Control Operation :
If equipped with remote start, the climate
control system may run when the vehicle is
started remotely. If equipped with heated or
ventilated seats or a heated steering wheel,
these features may come on during a
remote start. See Remote Vehicle Start 020,
Heated and Ventilated Front Seats 052, and
Heated Steering Wheel 0100.
Sensors

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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264 Driving and Operating
Weather Conditions Affecting ACC
If the interior temperature is extremely
high, the instrument cluster may indicate
that ACC is temporarily unavailable. This can
be caused by extreme hot weather
conditions with direct sunlight on the front
camera. ACC will return to normal operation
once the cabin temperature is lower.
Conditions that are associated with low
visibility, such as fog, rain, snow, or road
spray, may limit ACC performance. Water
droplets from rain or snow that remain on
the windshield may also limit ACC’s ability
to detect objects.
{Warning
Camera visibility may be limited and the
ACC system may not work properly if the
windshield is not clear. Do not use ACC if
moisture is present on the inside of the
windshield or the windshield washer is
used in cold weather. Turn on the front
defroster and make sure the windshield is
clear before using ACC. Before driving,
check that the windshield wipers are in
good condition and replace them if worn.Lighting Conditions Affecting ACC
The ACC front camera can be affected by
poor lighting conditions, and ACC may have
limited performance when:
.There are changes in brightness, such as
entering and exiting tunnels, bridges, and
overpasses.
.Low sun angles cause the camera to not
detect objects, or it is more difficult to
detect objects in the same traffic lane.
.Lighting is poor in the evening or early
morning
.There are multiple changes in brightness
or shadows along the vehicle roadway.
.In a tunnel without the headlamps on,
or in a tunnel when there is a vehicle in
front that does not have its taillamps on.
.Subjected to strong light from opposing
lane traffic in the front of the vehicle,
such as high-beam headlamps from
oncoming traffic.
Accessory Installations and Vehicle
Modifications
Do not install or place any object around
the front camera windshield area that would
obstruct the front camera view. Do not install objects on top of the vehicle
that overhang and obstruct the front
camera, such as a canoe, kayak, or other
items that can be transported on the
vehicle roof.
Do not modify the hood, headlamps, or fog
lamps, as this may limit the camera’s ability
to detect an object.
Cleaning the Sensing System
The camera sensor on the windshield behind
the rearview mirror can become blocked by
snow, ice, dirt, mud, or debris. This area
needs to be cleaned for ACC to operate
properly.
The vehicle headlamps may need to be
cleaned due to dirt, snow, or ice. Objects
that are not illuminated correctly may be
difficult to detect.
If ACC will not operate, regular cruise control
may be available. See
“Switching Between
ACC and Regular Cruise Control” previously
in this section. Always consider driving
conditions before using either cruise control
system.
For cleaning instructions, see “Washing the
Vehicle” underExterior Care 0398.