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GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
48 Keys, Doors, and Windows
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 60 . 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. 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 36 .
This feature is turned on or off
through vehicle personalization. See
Vehicle Personalization 0 167 .
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.
Page 50 of 511

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Keys, Doors, and Windows 49See “ Rear Window Defogger ” under
Dual Automatic Climate Control
System 0 246 .
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 1. 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
Page 51 of 511

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
50 Keys, Doors, and Windows 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 0 167 .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 0 488 .
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 The mirror will automatically reduce
the glare of the headlamps from
behind. The dimming feature comes
on each time the vehicle is started.
Page 52 of 511

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Keys, Doors, and Windows 51
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
{ WarningChildren could be seriously
injured or killed if caught in the
path of a closing window. Never
leave 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 33 . Crew/Double Cab Premium Trim
Shown, Other Models Similar
The windows work when the vehicle
is in ON/RUN, ACC/ACCESSORY,
or Retained Accessory Power
(RAP). See Retained Accessory
Power (RAP) 0 277 .
Press or pull the switch to open or
close the window.
The windows will be temporarily
disabled if the window switches are
used repeatedly within a short time.
Page 53 of 511

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
52 Keys, Doors, and Windows 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
Express-down/up allows the
windows to be opened or closed
without holding the window switch. Press the window switch fully down
or pull it up, and quickly release it to
engage. Briefly press or pull the
same switch to stop window
movement.
Express Window Obstacle
Detection The express-up 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 as normal after the object or
condition is removed.
Obstacle Detection Override
{ Warning
If obstacle detection override is
activated, the window will not
reverse automatically. You or
others could be injured and the
window could be damaged.
Before you use obstacle detection
override, make sure that all
people and obstructions are clear
of the window path. The window can be closed by
holding the window switch in the up
position if conditions prevent it from
express closing.
Programming the Power
Windows Programming may be necessary if
the vehicle's battery has been
disconnected or discharged. If the
window is unable to express-up,
program the window:
1. Close all doors.
2. Place the ignition in ACC/
ACCESSORY or ON/RUN.
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. Press the power window switch
until the window is fully open
and briefly hold.
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GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Keys, Doors, and Windows 53
Rear Windows Power Sliding Rear Window
If equipped, the power sliding rear
window works when the ignition has
been turned to ACC/ACCESSORY
or ON/RUN, or when Retained
Accessory Power (RAP) is active.
See Retained Accessory Power
(RAP) 0 277 .
.
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. Detach the sun visor from the
center mount to pivot to the side
window and, if equipped, extend
along the rod. Roof Sunroof
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) 0 277 .
Slide Switch
Express-Open/Express-Close : To
express-open the sunroof, fully
press and release
I . Press the
switch again to stop the movement.
Page 55 of 511

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
54 Keys, Doors, and Windows To express-close the sunroof, fully
press and release
K . Press the
switch again to stop the movement.
Open/Close (Manual Mode) : To
open the sunroof, press and hold
I . Release the switch to stop the
movement. Press and hold
K to
close the sunroof. Release the
switch to stop the movement.
Tilt Switch
Vent : From the closed position,
press
J to vent the sunroof. Press
K 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 again.
If frost or other conditions prevent
closing, override the feature by
closing the sunroof in manual
mode. To stop movement, release
the switch.
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.
Page 56 of 511

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Seats and Restraints 55
Seats and
Restraints Head Restraints Head Restraints . . . . . . . . . . . . . . . 56
Front Seats Seat Adjustment . . . . . . . . . . . . . . . 57
Center Seat . . . . . . . . . . . . . . . . . . . . 57
Power Seat Adjustment . . . . . . . . 58
Lumbar Adjustment . . . . . . . . . . . . 58
Reclining Seatbacks . . . . . . . . . . . 59
Memory Seats . . . . . . . . . . . . . . . . . 60
Heated and Ventilated Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . 62
Rear Seats Rear Seats (Double Cab Full
Bench) . . . . . . . . . . . . . . . . . . . . . . . 63
Rear Seats (Split Bench) . . . . . . 64
Safety Belts Safety Belts . . . . . . . . . . . . . . . . . . . . 65
How to Wear Safety Belts
Properly . . . . . . . . . . . . . . . . . . . . . . 66
Lap-Shoulder Belt . . . . . . . . . . . . . 67
Safety Belt Use During
Pregnancy . . . . . . . . . . . . . . . . . . . . 70
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . 71 Safety Belt Extender . . . . . . . . . . . 71
Safety System Check . . . . . . . . . . 71
Safety Belt Care . . . . . . . . . . . . . . . 72
Replacing Safety Belt System
Parts after a Crash . . . . . . . . . . . 72
Airbag System Airbag System . . . . . . . . . . . . . . . . . 73
Where Are the Airbags? . . . . . . . 74
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . 75
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . 77
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . . . 77
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . 78
Airbag On-Off Switch . . . . . . . . . . 79
Passenger Sensing System . . . 81
Servicing the Airbag-Equipped
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 85
Adding Equipment to the
Airbag-Equipped Vehicle . . . . . 86
Airbag System Check . . . . . . . . . . 87
Replacing Airbag System Parts
after a Crash . . . . . . . . . . . . . . . . . 87
Child Restraints
Older Children . . . . . . . . . . . . . . . . . 87
Infants and Young Children . . . . 89
Child Restraint Systems . . . . . . . 91 Where to Put the Restraint . . . . . 93
Lower Anchors and Tethers for
Children (LATCH System) . . . . 95
Replacing LATCH System
Parts After a Crash . . . . . . . . . 106
Securing Child Restraints (With
the Safety Belt in the
Rear Seat) . . . . . . . . . . . . . . . . . . 106
Securing Child Restraints (With
the Safety Belt in the Center
Front Seat) . . . . . . . . . . . . . . . . . . 110
Securing Child Restraints (With
the Safety Belt in the Front
Passenger Seat) . . . . . . . . . . . . 110