
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
42 Keys, Doors, and Windows
Lockout Protection If the ignition is on or in ACC/
ACCESSORY and the power door
lock switch is pressed with the
driver door open, all the doors will
lock and only the driver door will
unlock.
If the vehicle is off and locking is
selected while a door is open, when
all doors are closed the vehicle will
check for RKE transmitters inside.
If an RKE transmitter is detected,
and the number of RKE transmitters
has not reduced, the driver door will
unlock and the horn will chirp three
times.
This can be manually overridden by
pressing and holding
Q on the
power door lock switch. Unlocked Door Anti-Lockout
If Unlocked Door Anti-Lockout is
turned on and the vehicle is off, the
driver door is open, and locking is
requested, all the doors will lock and
the driver door will remain open.
Press the button again to lock the
driver door. The Unlocked Door
Anti-Lockout feature can be turned
on or off. See Vehicle
Personalization 0 165 .
Safety Locks The rear door safety locks prevent
passengers from opening the rear
doors from inside the vehicle. Crew/Double Cab Premium Trim
Shown, Others Similar
Press
{ to activate the safety locks
on the rear doors. The indicator light
comes on when activated. Press
{again to deactivate. The vehicle
must be on, in ACC/ACCESSORY,
or in Retained Accessory Power
(RAP). See Retained Accessory
Power (RAP) 0 260 .
If the indicator light flashes, the
feature may not be working properly.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 43
Doors Tailgate
{ WarningIt is extremely dangerous to ride
on the tailgate, even when the
vehicle is operated at low speeds.
People riding on the tailgate can
easily lose their balance and fall
in response to vehicle
maneuvers. Falling from a moving
vehicle may result in serious
injuries or death. Do not allow
people to ride on the tailgate. Be
sure everyone in your vehicle is in
a seat and using a seat belt
properly.
If equipped, to lock or unlock the
tailgate, use the RKE transmitter or
the key. See Remote Keyless Entry
(RKE) System Operation 0 37 .
Open the tailgate by lifting up on its
handle while pulling the
tailgate down. To shut the tailgate, firmly push it
upward until it latches.
After closing the tailgate, pull it back
to be sure it latches securely.
Power Assist Steps 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. 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 DIC message displays.
3. Kick the switch again to return
to normal operation.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 45Fast Flash : Vehicle is unsecured.
A door, the tailgate, or the hood
is open.
Slow Flash : Alarm system is
armed.
Arming the Alarm System 1. Turn off the vehicle.
2. Lock the vehicle in one of
two ways:
.
Use the RKE transmitter.
.
With a door open, press
Qon the interior of the door.
3. After 30 seconds, the alarm
system will arm and the
indicator light will begin to
slowly flash. Pressing
Q on the
RKE transmitter a second time
will bypass the 30-second
delay and immediately arm the
alarm system.
The vehicle alarm system will not
arm if the doors are locked with
the key. If the driver door is opened without
first unlocking with the RKE
transmitter, the horn will chirp and
the lights will flash to indicate
pre-alarm. If the vehicle is not
started, or the door is not unlocked
by pressing
K on the RKE
transmitter during the 10-second
pre-alarm, the alarm will be
activated.
The alarm will also be activated if a
passenger door, the tailgate, or the
hood is opened without first
disarming the system. When the
alarm is activated, the turn signals
flash and the horn sounds for about
30 seconds. The alarm system will
then re-arm to monitor for the next
unauthorized event.
Disarming the Alarm System To disarm the alarm system or turn
off the alarm if it has been activated:
.
Press
K on the RKE transmitter.
.
Start the vehicle. To avoid setting off the alarm by
accident:
.
Lock the vehicle after all
occupants have exited.
.
Always unlock a door with the
RKE transmitter.
Unlocking the driver door with
the key will not disarm the
system or turn off the alarm.
How to Detect a Tamper
Condition If
K is pressed on the RKE
transmitter and the horn chirps three
times, an alarm occurred previously
while the alarm system was armed.
If the alarm has been activated, a
message will appear on the DIC.
Inclination Sensor and
Intrusion Sensor
In addition to the standard
theft-deterrent system features, this
system may also have an inclination
sensor and intrusion sensor.

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
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Keys, Doors, and Windows 55The 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) 0 260 .
Slide Switch
Express-Open/Express-Close : To
express-open the sunroof, fully
press and release
I . Press the
switch again to stop the movement. 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
58 Seats and Restraints
Head Restraints Front Seats The vehicle ’ s front seats have
adjustable head restraints in the
outboard seating positions.
{ WarningWith 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.