GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
34 Keys, Doors, and Windows
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 remote keys
matched to an immobilizer control unit in
your vehicle. Only a correctly matched
remote key will start the vehicle. If the
remote key 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
(accessory mode, on, off), and the remote
key appears to be undamaged, try another
remote key. Or, you may try placing the
remote key in the remote key pocket
located in the center console. SeeRemote
Key Operation 015.
If the ignition mode will not change with
the other remote key or with the remote
key in the remote key pocket, your vehicle
needs service. If the ignition does change
modes, the first remote key may be faulty. See your dealer who can service the
theft-deterrent system and have a new
remote key programmed to the vehicle.
It is possible for the immobilizer system to
learn new or replacement remote keys. Up
to eight remote keys can be programmed
for the vehicle. To program additional
remote keys, see "Programming Remote
Keys to the Vehicle" under
Remote Key
Operation 015.
Do not leave the remote key or device that
disarms or deactivates the vehicle theft
system in the vehicle.
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
If equipped, the passenger side mirror is
convex shaped. A convex mirror 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
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 2500 HD/3500 HD Owner Manual (GMNA-
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Trailer-Tow Mirrors
Extending Mirrors
Trailer tow mirrors can extend out for better
visibility when towing a trailer.
If equipped, grasp the mirror housing firmly
and pull back in one motion, arching slightly
toward the rear of the vehicle.
To return the mirror to its original position,
reverse the motion.
Auxiliary Cargo Mirror Lamps
If equipped, cargo mirror lamps face
rearward to provide more light on the sides
of the vehicle, if needed. SeeExterior Cargo
Lamps 0149.
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
System 0254.
Power Mirrors
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
36 Keys, Doors, and Windows
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.
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. See Task Lighting 0148. 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 0151 and
Exit Lighting 0151.
Memory Mirrors
The vehicle may have memory mirrors. See
Memory Seats 051.
Lane Change Alert (LCA)
The vehicle may have LCA. See Lane Change
Alert (LCA) 0268.
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.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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Keys, Doors, and Windows 37
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, double press and holdQon the
remote key for approximately one second to
remotely fold the exterior mirrors. Double
press and hold
Kon the remote key for
approximately one second to unfold. See
Remote Key Operation 015.
This feature can be turned on or off. To
view available settings from the
infotainment screen, touch Settings >
Vehicle > Comfort and Convenience.
Heated Mirrors
If equipped with heated mirrors:
1REAR : Press to heat the outside
mirrors.
See “Rear Window Defogger” underDual
Automatic Climate Control System 0193.
Automatic Dimming Mirror
If equipped, the driver and passenger
outside mirrors automatically adjust for the
glare of headlamps from behind. This
feature comes on when the vehicle is
started.
Blind Spot Mirrors
If equipped, there is a small convex mirror
built into the upper and outer corner of the
driver outside mirror. It can show objects
that may be in the vehicle's blind zone.
Driving with the Blind Spot Mirror
Actual Mirror View
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
38 Keys, Doors, and Windows
1. When the approaching vehicle is a longdistance away, the image in the main
mirror is small and near the inboard
edge of the mirror.
2. As the vehicle gets closer, the image in the main mirror gets larger and moves
outboard.
3. As the vehicle enters the blind zone, the image transitions from the main mirror
to the blind spot mirror.
4. When the vehicle is in the blind zone, the image only appears in the blind spot
mirror.
Using the Outside Mirror with the Blind
Spot Mirror
1. Set the main mirror so that the side ofthe vehicle can just be seen and the
blind spot mirror has an
unobstructed view.
2. When checking for traffic or before changing a lane, look at the main driver/
passenger side mirror to observe traffic
in the adjacent lane, behind your vehicle.
Check the blind spot mirror for a vehicle
in the blind zone. Then, glance over your
shoulder to double check before moving
slowly into the adjacent lane.
Reverse Tilt Mirrors
If equipped with reverse tilt mirrors and
memory seats, the passenger and/or driver
mirror tilts to a preselected position when
the vehicle is in R (Reverse). This allows the
curb to be seen when parallel parking.
The mirror(s) may move from their tilted
position when:
.The vehicle is shifted out of R (Reverse),
or remains in R (Reverse) for about
30 seconds.
.The vehicle is turned off.
.The vehicle is driven in R (Reverse) above
a set speed.
To view available settings from the
infotainment screen, touch Settings >
Vehicle > Comfort and Convenience.
Interior Mirrors
Interior Rearview Mirrors
Adjust the rearview mirror for a clear view
of the area behind your vehicle.
Do not spray glass cleaner directly on the
mirror. Use a soft towel dampened with
water.
Manual Rearview Mirror
If equipped, push the tab forward for
daytime use and pull it rearward for
nighttime use to avoid glare from the
headlamps from behind.
Automatic Dimming Rearview
Mirror
If equipped, the mirror will automatically
reduce the glare of the headlamps from
behind. The dimming feature comes on each
time the vehicle is started.
Rear Camera Mirror
If equipped, this automatic dimming mirror
provides a wide angle camera view of the
area behind the vehicle.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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Keys, Doors, and Windows 39
Pull the tab to turn on the display. Push the
tab to turn it off. When off the mirror is
automatic dimming. Adjust the mirror for a
clear view of the area behind the vehicle
while the display is off.PressVto scroll through the adjustment
options.
Press
tanduto adjust the settings using
the indicators on the mirror. The indicators
will remain visible for five seconds after the
last button activation, and the settings will
remain saved. The adjustment options are:
.Brightness
.Zoom
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
40 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.
.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.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Keys, Doors, and Windows 41
Truck Bed Camera Rearview
Mirror
If equipped, this automatic dimming mirror
provides a video image, when activated, to
allow the driver to momentarily check the
pickup bed area contents or to align and
attach a gooseneck or fifth-wheel trailer.
.Push the button at the bottom of the
mirror once to activate the display.
.Push the button a second time to zoom
the camera’s view.
.Push the button a third time to
deactivate the display.
When the vehicle is in R (Reverse) and
button has been pressed, the display will
remain on until the driver deactivates it.
When not in R (Reverse), the video image
will time out after eight seconds.
When in Zoomed Mode, the display features
guidelines to help the driver align the
vehicle when attaching a trailer. Both the
horizontal and vertical guideline’s position
can be adjusted by the driver.
To adjust the position of the horizontal
guideline, press and hold the button for
eight seconds until it starts blinking. Each
subsequent button press scrolls the position
of this line through its range of possible
settings. Once the horizontal guideline is in the
desired location, press and hold the button
for another three seconds and repeat the
above step for the vertical guideline
programing. To readjust the horizontal
location of the guidelines after adjusting the
vertical location, press and hold the button
for three seconds.
After eight seconds since the last button
press, the position of the guidelines is
locked into memory.
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.