
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
54 Keys, Doors, and Windows
Power Assist Steps
{Warning
To avoid personal injury or
property damage, before entering
or exiting the vehicle, be sure the
power assist step is fully
extended. Do not step on the
power assist step while it is
moving. Never place hands or
other body parts between the
extended power assist step and
the vehicle.
If equipped, the power assist steps,
when enabled, will extend when the
door is opened. They will retract
three seconds after the door is
closed or immediately if the vehicle
starts moving.
Keep hands, children, pets, objects,
and clothing clear of the power
assist steps when in motion.
The steps will reverse direction if
there is an obstruction. If possible,
carefully remove the obstruction,
then open and close the door on the same side to complete the motion.
If the obstruction is not cleared, the
assist steps remain extended.
Slight movement of the steps while
extended is normal.
Kick Switch
1. Place the vehicle in P (Park)
and unlock the doors.
2. Kick the switch to extend the power assist step to the tire.
A Driver Information Center
(DIC) message displays.
3. Kick the switch again to return to normal operation.
Center Stack Switch
The power assist steps can be
extended to the tire by pressing
j.
When extending the steps with
j,
the kick switch is disabled. The
vehicle must be in P (Park) or
N (Neutral).
To extend the steps:
. Press
jto extend both steps.
A DIC message displays.
. Press
jagain to extend to the
tire. A DIC message displays.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
Keys, Doors, and Windows 57
the transmitter in the transmitter
pocket in the center console. See
Keys031.
If the ignition modes will not change
with the other transmitter or 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 a new or
replacement transmitter. Up to eight
transmitters can be programmed for
the vehicle. To program additional
transmitters, see your dealer.
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
0355.
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 031. 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.
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-1500-11698638) - 2019 - CRC - 5/13/19
58 Keys, Doors, and Windows
Using hood-mounted air deflectors
and add-on convex mirror
attachments could decrease mirror
performance.
Power Mirrors
1. Select}or|for the driver or
passenger side mirror. The
switch will illuminate.
2. Press the arrows on the control pad to move the mirror up,
down, right, or left. 3. Adjust each outside mirror so
that a little of the vehicle and
the area behind it can be seen.
The mirrors may be equipped with a
memory function that works with the
memory seats. See Memory Seats
0 74.
There may be cargo lamps on the
bottom of the mirrors. See Exterior
Cargo Lamps 0185.
Folding Mirrors
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.
Power Folding
If equipped with power folding
mirrors:
1. Press
gto fold the mirrors in
to the folded position.
2. Press
gagain to fold the
mirrors out to the driving
position.
Resetting the Power Folding
Mirrors
Reset the power folding mirrors if:
. The mirrors are accidentally
obstructed while folding.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
Keys, Doors, and Windows 59
.The mirrors 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.
Remote Folding Mirrors
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 (Keyless Access) 034 or
Remote Keyless Entry (RKE)
System Operation (Key Access)
0 42. This feature can be turned on or off.
See
Vehicle Personalization 0170.
Task Lighting
If equipped, task lighting projects
light from the outside mirrors to the
sides of the vehicle. See Task
Lighting 0185.
Advanced Trailering Vision
System Side Cameras
If equipped, the Advanced Trailering
Vision System side cameras are on
the bottom of the outside mirrors. To
locate for cleaning, see “Surround
Vision (360 Degrees)” under
Assistance Systems for Parking or
Backing 0259.
Lane Change Alert (LCA)
The vehicle may have LCA. See
Lane Change Alert (LCA) 0272.
Side Blind Zone Alert
The vehicle may have Side Blind
Zone Alert. See Side Blind Zone
Alert (SBZA) 0271.
Heated Mirrors
If equipped with heated mirrors:
1REAR : Press to heat the
outside mirrors.
See “Rear Window Defogger” under
Dual Automatic Climate Control
System 0193.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
60 Keys, Doors, and Windows
Driving with the Blind Spot
Mirror
Actual Mirror View1. 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 theside 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 0170.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
88 Seats and Restraints
Warning (Continued)
airbags. Airbags are designed to
work with seat belts, not replace
them. Also, airbags are not
designed to inflate in every crash.
In some crashes seat belts are
the only restraint. SeeWhen
Should an Airbag Inflate? 090.
Wearing your seat belt during a
crash helps reduce your chance
of hitting things inside the vehicle
or being ejected from it. Airbags
are “supplemental restraints” to
the seat belts. Everyone in the
vehicle should wear a seat belt
properly, whether or not there is
an airbag for that person.
{Warning
Because airbags inflate with great
force and faster than the blink of
an eye, anyone who is up
against, or very close to, any
(Continued)
Warning (Continued)
airbag when it inflates can be
seriously injured or killed. Do not
sit unnecessarily close to any
airbag, as you would be if sitting
on the edge of the seat or leaning
forward. Seat belts help keep you
in position before and during a
crash. Always wear a seat belt,
even with airbags. The driver
should sit as far back as possible
while still maintaining control of
the vehicle. The seat belts and
the front outboard passenger
airbags are most effective when
you are sitting well back and
upright in the seat with both feet
on the floor.
Occupants should not lean on or
sleep against the door or side
windows in seating positions with
seat-mounted side impact airbags
and/or roof-rail airbags.
{Warning
Children who are up against,
or very close to, any airbag when
it inflates can be seriously injured
or killed. Always secure children
properly in the vehicle. To read
how, seeOlder Children 0100 or
Infants and Young Children
0 101.
There is an airbag readiness light
on the instrument cluster, which
shows the airbag symbol.
The system checks the airbag
electrical system for malfunctions.
The light tells you if there is an
electrical problem. See Airbag
Readiness Light 0149.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
90 Seats and Restraints
Driver Side Crew Cab Shown,Passenger Side Double and Regular Cabs Similar
The roof-rail airbags for the driver,
front outboard passenger, and
second row outboard passengers
are in the ceiling above the side
windows.
{Warning
If something is between an
occupant and an airbag, the
airbag might not inflate properly
or it might force the object into (Continued)
Warning (Continued)
that person causing severe injury
or even death. The path of an
inflating airbag must be kept
clear. Do not put anything
between an occupant and an
airbag, and do not attach or put
anything on the steering wheel
hub or on or near any other
airbag covering.
Do not use seat accessories that
block the inflation path of a
seat-mounted side impact airbag.
Never secure anything to the roof
of a vehicle with roof-rail airbags
by routing a rope or tie‐down
through any door or window
opening. If you do, the path of an
inflating roof-rail airbag will be
blocked.
When Should an Airbag
Inflate?
This vehicle is equipped with
airbags. SeeAirbag System 087.
Airbags are designed to inflate if the
impact exceeds the specific airbag
system's deployment threshold.
Deployment thresholds are used to
predict how severe a crash is likely
to be in time for the airbags to
inflate and help restrain the
occupants. The vehicle has
electronic sensors that help the
airbag system determine the
severity of the impact. Deployment
thresholds can vary with specific
vehicle design.
Frontal airbags are designed to
inflate in moderate to severe frontal
or near frontal crashes to help
reduce the potential for severe
injuries, mainly to the driver's or
front outboard passenger's head
and chest.
Whether the frontal airbags will or
should inflate is not based primarily
on how fast the vehicle is traveling.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - CRC - 5/13/19
92 Seats and Restraints
full or partial ejection in rollover
events, although no system can
prevent all such ejections.
But airbags would not help in many
types of collisions, primarily
because the occupant's motion is
not toward those airbags. SeeWhen
Should an Airbag Inflate? 090.
Airbags should never be regarded
as anything more than a supplement
to seat belts.
What Will You See after
an Airbag Inflates?
After frontal and seat-mounted side
impact airbags inflate, they quickly
deflate, so quickly that some people
may not even realize the airbags
inflated. Roof-rail airbags may still
be at least partially inflated for some
time after they inflate. Some
components of the airbag module
may be hot for several minutes. For
location of the airbags, see Where
Are the Airbags? 089.
The parts of the airbag that come
into contact with you may be warm,
but not too hot to touch. There may be some smoke and dust coming
from the vents in the deflated
airbags. Airbag inflation does not
prevent the driver from seeing out of
the windshield or being able to steer
the vehicle, nor does it prevent
people from leaving the vehicle.
{Warning
When an airbag inflates, there
may be dust in the air. This dust
could cause breathing problems
for people with a history of
asthma or other breathing trouble.
To avoid this, everyone in the
vehicle should get out as soon as
it is safe to do so. If you have
breathing problems but cannot
get out of the vehicle after an
airbag inflates, then get fresh air
by opening a window or a door.
If you experience breathing
problems following an airbag
deployment, you should seek
medical attention.
The vehicle has a feature that may
automatically unlock the doors, turn
on the interior lamps and hazard
warning flashers, and shut off the
fuel system after the airbags inflate.
The feature may also activate,
without airbag inflation, after an
event that exceeds a predetermined
threshold. After turning the ignition
off and then on again, the fuel
system will return to normal
operation; the doors can be locked,
the interior lamps can be turned off,
and the hazard warning flashers can
be turned off using the controls for
those features. If any of these
systems are damaged in the crash
they may not operate as normal.
{Warning
A crash severe enough to inflate
the airbags may have also
damaged important functions in
the vehicle, such as the fuel
system, brake and steering
systems, etc. Even if the vehicle
appears to be drivable after a
(Continued)