
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
46 Keys, Doors, and Windows The inclination sensor can set off
the alarm if it senses movement of
the vehicle, such as a change in
vehicle orientation.
The intrusion sensor monitors the
vehicle interior, and can activate the
alarm if it senses unauthorized entry
into the vehicle ’ s interior. Do not
allow passengers or pets to remain
in the vehicle when the intrusion
sensor is activated.
Before arming the theft-deterrent
system and activating the intrusion
sensor:
.
Make sure all doors and
windows are completely closed.
.
Secure any loose items such as
sunshades.
.
Make sure there are no
obstructions blocking the
sensors in the front overhead
console.
.
Close DVD screens, if equipped,
before leaving the vehicle. Inclination and Intrusion
Sensors Disable Switch
It is recommended that the intrusion
and inclination sensors be
deactivated if pets are left in the
vehicle or if the vehicle is being
transported.
With the vehicle turned off, press
o in the front overhead console.
The indicator light will come on
momentarily, indicating that these
sensors have been disabled for the
next alarm system arming cycle. Immobilizer See Radio Frequency Statement
0 475 .
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.
The security light, in the instrument
cluster, comes on if there is a
problem with arming or disarming
the theft-deterrent system.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 47When trying to start the vehicle, the
security light comes 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 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 0 381 .
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
0 34 . To program additional
transmitters, see your dealer.
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
{ WarningA 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.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
48 Keys, Doors, and Windows Using hood-mounted air deflectors
and add-on convex mirror
attachments could decrease mirror
performance.
Trailer-Tow Mirrors
If equipped, adjust trailer-tow
mirrors for a clear view of the area
behind you. Manually pull out the
mirror head to extend it for better
visibility when towing a trailer.
The lower portion of the mirror is
convex. A convex mirror's surface is
curved to see more from the driver seat. The convex mirror can be
adjusted manually to the driver
preferred position for better vision.
The mirror may have a turn signal
arrow that flashes in the direction of
the turn or lane change.
Power Mirrors Using hood-mounted air deflectors
and add-on convex mirror
attachments could decrease mirror
performance.
Base Power Mirrors
The power mirror controls are on the
driver door. 1. Press (1) or (2) to select the
driver or passenger side mirror.
2. Press one of the four 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. Move the selector switch to the
center position when not
adjusting either outside mirror.
Crew/Double Cab Premium
Shown, Other Models Similar
1. Press (1) or (2) to select the
driver or passenger side mirror.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 492. Press one of the four arrows on
the control pad while the
indicator light on button (1)
or (2) is illuminated, 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 either (1) or (2) again to
deselect the mirror.
If you do not deselect the mirror, the
feature will turn off after about
one minute.
The mirrors may include a memory
function that works with the memory
seats. See Memory Seats 0 62 .Folding Mirrors
Crew/Double Cab Premium Trim
Shown, Other Models Similar
Power Folding If equipped with power folding
mirrors:
1. Press (2) to fold the mirrors out
to the driving position.
2. Press (2) again to fold the
mirrors in to the folded position.
The mirrors may also include a
memory function that works with the
memory seats. See Memory Seats
0 62 . Resetting the Power Folding
Mirrors
Reset the power folding mirrors if:
.
The mirrors are accidentally
obstructed while folding.
.
They are accidentally manually
folded/unfolded.
.
The mirrors will not stay in the
unfolded position.
.
The mirrors vibrate at normal
driving speeds.
Manually fold both mirrors if they
are out of sync. Fold and unfold the
mirrors three times using the mirror
controls to reset them to their
normal position. A popping noise
may be heard. This sound is normal
after a manual folding operation.
Manual Folding
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
50 Keys, Doors, and Windows Auto Mirror Folding If equipped, with the ignition off,
press and hold
Q on the RKE
transmitter for approximately
one second to automatically fold the
exterior mirrors. Press and hold
Kon the RKE transmitter for
approximately one second to unfold.
See Remote Keyless Entry (RKE)
System Operation 0 37 .
This feature is turned on or off
through vehicle personalization. See
Vehicle Personalization 0 165 .
Turn Signal Indicator If equipped, indicator lights on the
mirror flash in the direction of the
turn or lane change.
Heated Mirrors If equipped with heated mirrors:
K : Press to heat the outside
mirrors. If the vehicle has trailer-tow
mirrors, only the upper glass of the
mirror is heated. The lower convex
part of the trailer-tow mirrors is not
heated. See “ Rear Window Defogger ” under
Dual Automatic Climate Control
System 0 228 .
Automatic Dimming
Mirror If equipped, the driver outside mirror
automatically adjusts for the glare of
the 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 Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 511. When the approaching vehicle
is a long distance 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 of the 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 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) return to the original
position when:
.
The vehicle is shifted out of
R (Reverse), or remains in
R (Reverse) for about
30 seconds.
.
The ignition is turned off.
.
The vehicle is driven in
R (Reverse) above a set speed.
To turn this feature on or off, see
Vehicle Personalization 0 165 .Interior Mirrors Interior Rearview Mirrors Adjust the rearview mirror for a clear
view of the area behind your
vehicle.
If equipped with OnStar, the vehicle
may have three control buttons at
the bottom of the mirror. See your
dealer for more information about
OnStar and how to subscribe to it.
See OnStar Overview 0 479 .
Do not spray glass cleaner directly
on the mirror. Use a soft towel
dampened with water.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
52 Keys, Doors, and Windows
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 The mirror will automatically reduce
the glare of the headlamps from
behind. The dimming feature comes
on each time the vehicle is started.
Windows
{ WarningNever 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
prevent operation of the windows.
See Keys 0 34 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 53
Crew/Double Cab Premium Trim
Shown, Other Models Similar
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) 0 260 .
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
Crew/Double Cab Premium
Shown, Other Models Similar
This feature stops the rear door
passenger window switches from
working except from the driver
position.
Press
Z to engage the rear
window lockout feature. The
indicator light is on when engaged.
Press
Z again to disengage. Window 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.
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.