
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
38 Keys, Doors, and Windows
To replace the battery:
1. Separate and remove the backcover of the transmitter with a
flat, thin object, such as a coin.
2. Press and slide the batterydown toward the pocket of the
transmitter in the direction of
the key ring. Do not use a
metal object.
3. Remove the battery.
4. Insert the new battery, positive side facing up. Replace with a
CR2032 or equivalent battery.
5. Push together the transmitter back cover top side first, and
then the bottom toward the
key ring.
Remote Vehicle Start
If equipped with the remote start
feature, the climate control system
will come on when the vehicle is
started remotely, depending on the
outside temperature.
The rear defog and heated and
ventilated seats, if equipped, may
also come on.
See Heated and Ventilated Front
Seats 062 and Vehicle
Personalization 0167.
Laws in some communities may
restrict the use of remote starters.
Check local regulations for any
requirements on remote starting of
vehicles.
Do not use remote start if the
vehicle is low on fuel.
The vehicle cannot be remote
started if:
. The key is in the ignition.
. The hood is not closed.
. There is an emission control
system malfunction and the
malfunction indicator lamp is on.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Keys, Doors, and Windows 47
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. 2. 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 060.

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 TrimShown, 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
Qon the RKE
transmitter for approximately
one second to automatically fold the
exterior mirrors. Press and hold
K
on the RKE transmitter for
approximately one second to unfold.
See Remote Keyless Entry (RKE)
System Operation 036.
This feature is turned on or off
through vehicle personalization. See
Vehicle Personalization 0167.
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.

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 0167.
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 0488.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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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 FrontSeats . . . . . . . . . . . . . . . . . . . . . . . . . 62
Rear Seats
Rear Seats (Double Cab FullBench) . . . . . . . . . . . . . . . . . . . . . . . 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
56 Seats and Restraints
Head Restraints
Front Seats
The vehicle’s front seats have
adjustable head restraints in the
outboard seating positions.
{Warning
With head restraints that are not
installed and adjusted properly,
there is a greater chance that
occupants will suffer a neck/
spinal injury in a crash. Do not
drive until the head restraints for
all occupants are installed and
adjusted properly.
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.The height of the head restraint can
be adjusted. Pull the head restraint
up to raise it. Try to move the head
restraint to make sure that it is
locked in place.
To lower the head restraint, press
the button, located on the top of the
seatback, and push the restraint
down. Try to move 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Seats and Restraints 57
Rear Seats
The rear seat has adjustable
headrests in the outboard seating
positions.
The height of the headrest can be
adjusted. Pull the headrest up to
raise it. To lower the headrest, push
the headrest down.
If you are installing a child restraint
in the rear seat, see“Securing a
Child Restraint Designed for the
LATCH System” underLower
Anchors and Tethers for Children
(LATCH System) 095.
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.
To adjust a manual seat:
1. Pull the handle at the front of the seat.
2. Slide the seat to the desired position and release the
handle.
3. Try to move the seat back and forth to be sure it is locked in
place.
To adjust the seatback, see
Reclining Seatbacks 059.
To adjust the lumbar support,
if equipped, see Lumbar Adjustment
0 58.
Center Seat
If equipped, the center front
seatback doubles as an armrest and
cupholder/storage area for the driver
and passenger when the center
front seat is not used. Do not use it
as a seating position when the
seatback is folded down.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
58 Seats and Restraints
Power Seat Adjustment
To adjust a power seat, if equipped:
.Move the seat forward or
rearward by sliding the control
forward or rearward.
. If equipped, raise or lower the
front part of the seat cushion by
moving the front of the control
up or down.
. If equipped, raise or lower the
seat by moving the rear of the
control up or down.
To adjust the seatback, see
Reclining Seatbacks 059. To adjust the lumbar support, see
Lumbar Adjustment
058.
Some vehicles are equipped with a
feature that activates a vibrating
pulse alert in the driver seat to help
the driver avoid crashes. See Driver
Assistance Systems 0305.
Lumbar Adjustment
Manual Lumbar
If equipped, move the lever up or
down repeatedly to increase or
decrease lumbar support.
Power Lumbar
To adjust the power lumbar support,
if equipped:
.
Press and hold the control
forward to increase or rearward
to decrease upper and lower
lumbar support at the same time.
. If equipped, press and hold the
control up to increase upper
lumbar support and decrease
lower lumbar support.
Press and hold the control down
to increase lower lumbar support
and decrease upper lumbar
support.