2021 GMC SIERRA child seat

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Introduction 3
9:Dispose of Used Components Properly
P:Do Not Apply High Pressure Water
B:Engine Coolant Temperature
_:Flame/Fire Prohibited
H: Flammable
[:Forward Collision Alert
R:Fuse Block Cover Lock Location
+:Fuses
j:ISOFIX/LATCH System Child Restraints
Q:Keep Fuse Block Covers Properly
Installed
|: Lane Change Alert
@:Lane Departure Warning
A:Lane Keep Assist
*: Malfunction Indicator Lamp
::Oil Pressure
X:Park Assist
~:Pedestrian Ahead Indicator
O:Power
7:Rear Cross Traffic Alert
I:Registered Technician
/:Remote Vehicle Start
h:Risk of Electrical Fire
>:Seat Belt Reminders
I:Side Blind Zone Alert
h:Stop/Start
7:Tire Pressure Monitor
d:Traction Control/StabiliTrak/Electronic
Stability Control (ESC)
a: Under Pressure
V: Vehicle Ahead Indicator

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
10 Keys, Doors, and Windows
Warning (Continued)
children or others could be seriously
injured or killed. They could operate the
power window or other controls or make
the vehicle move. The windows will
function with the key in the ignition or
with the RKE transmitter in the vehicle,
and children or others could be caught in
the path of a closing window. Do not
leave children in a vehicle with the
ignition key or an RKE transmitter.
If the vehicle has the Keyless Access system,
the transmitter has a button on the side of
the transmitter used to remove the key.This key is used for the driver door and
glove box.
Press the button to remove the key. Never
pull the key out without pressing the
button.
See your dealer if a replacement key or
additional key is needed.
If it becomes difficult to turn a key, inspect
the key blade for debris. Periodically clean
with a brush or pick.
With an active OnStar or connected service
plan, an OnStar Advisor may remotely
unlock the vehicle. See
OnStar Overview
0 440. If locked out of the vehicle, see
Roadside
Assistance Program 0431.
If equipped with memory seats, RKE
transmitters 1 and 2 are linked to seating
positions of memory 1 or 2. See Memory
Seats 049.
Remote Keyless Entry (RKE)
System
See Radio Frequency Statement 0436.
If there is a decrease in the Remote Keyless
Entry (RKE) operating range:
.Check the distance. The transmitter may
be too far from the vehicle.
.Check the location. Other vehicles or
objects may be blocking the signal.
.Check the transmitter's battery. See
“Battery Replacement” later in this
section.
.If the transmitter is still not working
correctly, see your dealer or a qualified
technician for service.
Remote Keyless Entry (RKE)
System Operation (Key Access)
The RKE transmitter functions may work up
to 60 m (197 ft) away from the vehicle.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
18 Keys, Doors, and Windows
5. Place the new transmitter in thetransmitter pocket/insert.
6. Press ENGINE START/STOP. When the transmitter is learned, the DIC display
will show that it is ready to program the
next transmitter.
7. Remove the transmitter from the transmitter pocket/insert and press
Kor
Qon the transmitter.
To program additional transmitters,
repeat Steps 5–7.
When all additional transmitters are
programmed, press and hold ENGINE
START/STOP for approximately
12 seconds to exit programming mode.
8. Return the key back into the transmitter.
Starting the Vehicle with a Low
Transmitter Battery
If the transmitter battery is weak or if there
is interference with the signal, the DIC may
display NO REMOTE DETECTED or NO
REMOTE KEY WAS DETECTED PLACE KEY IN
TRANSMITTER POCKET THEN START YOUR
VEHICLE when starting the vehicle. To start the vehicle:
Transmitter Pocket without Bucket Seats
(Lower Compartment)
Transmitter Pocket with Bucket Seats 1. Place the transmitter in the transmitter
pocket/insert.
2. With the vehicle in P (Park) or N (Neutral) press the brake pedal and ENGINE
START/STOP.
Replace the transmitter battery as soon
as possible.
Battery Replacement
{Warning
Never allow children to play with the RKE
transmitter. The transmitter contains a
small battery, which can be a choking
hazard. If swallowed, internal burns can
occur, resulting in severe injury or death.
Seek medical attention immediately if a
battery is swallowed.
{Warning
To avoid personal injury, do not touch
metal surfaces on the RKE transmitter
when it has been exposed to extreme
heat. These surfaces can be hot to the
touch at temperatures above 59 °C
(138 °F).

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 21
Door Locks
{Warning
Unlocked doors can be dangerous.
.Passengers, especially children, can
easily open the doors and fall out of a
moving vehicle. The doors can be
unlocked and opened while the vehicle
is moving. The chance of being thrown
out of the vehicle in a crash is
increased if the doors are not locked.
So, all passengers should wear seat
belts properly and the doors should be
locked whenever the vehicle is driven.
.Young children who get into unlocked
vehicles may be unable to get out.
A child can be overcome by extreme
heat and can suffer permanent injuries
or even death from heat stroke.
Always lock the vehicle whenever
leaving it.
.Outsiders can easily enter through an
unlocked door when you slow down
or stop the vehicle. Locking the doors
can help prevent this from happening.There are several ways to lock and unlock
the vehicle.
From outside:
.Use the Remote Keyless Entry (RKE)
transmitter.
.Use Keyless Access, if equipped.
.Use the key in the driver door or the
passenger door, if equipped.
From inside, use the power door locks or the
manual door locks. To lock the door with
the manual door locks, push down on the
manual lock knob.
From inside, pull the door handle once to
unlock the door. Pull the handle again to
open the door.
See Vehicle Alarm System 031. Keyless Access
If equipped, the remote key must be within
1 m (3 ft) of the tailgate or door being
opened or locked. Press the button on the
door handle to open. See
“Keyless Access
Operation” inRemote Keyless Entry (RKE)
System Operation (Key Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013.
Free-Turning Locks
The door key lock cylinder turns freely when
either the wrong key is used, or the correct
key is not fully inserted. The free-turning
door lock feature prevents the lock from
being forced open. To reset the lock, turn it
to the vertical position with the correct key

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 23
Lockout Protection can be manually
overridden with the driver door open by
pressing and holding
Qon the power door
lock switch.
Open Door Anti-Lockout
If equipped, the Open 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
unlock. The Open Door Anti-Lockout feature
can be turned on or off. See Vehicle
Personalization 0131.
Safety Locks
The rear door safety locks prevent
passengers from opening the rear doors
from inside the vehicle.
The safety lock is on the inside edge of the
rear doors. To use the safety lock:
1. Move the lever down to the lock position.
2. Close the door.
3. Do the same for the other rear door.
To open a rear door when the safety lock
is on: 1. Unlock the door by activating the inside handle, by pressing the power door
unlock switch, or by using the Remote
Keyless Entry (RKE) transmitter.
2. Open the door from the outside. When the safety lock is enabled, adults and
older children will not be able to open the
rear door from the inside. Cancel the safety
locks to enable the doors to open from the
inside.
To cancel the safety lock:
1. Unlock the door and open it from the outside.
2. Move the lever up to unlock. Do the same for the other door.Doors
Tailgate
Manual Tailgate
{Warning
It 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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Keys, Doors, and Windows 41
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. SeeKeys (Key Access)07
or
Keys (Keyless Access) 09.
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) 0236.
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
With Power Folding Mirrors, Without Similar
This feature stops the rear door passenger
window switches from working except from
the driver position.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 45
Seats and Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . 45
Front Seats
Seat Adjustment . . . . . . . . . . . . . . . . . . . . . . . 46
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Power Seat Adjustment . . . . . . . . . . . . . . . . 47
Lumbar Adjustment . . . . . . . . . . . . . . . . . . . . 48
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . 48
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . . 49
Heated and Ventilated Front Seats . . . . . 52
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . . 54
Seat Belts
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
How to Wear Seat Belts Properly . . . . . . . 55
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . 57
Seat Belt Use During Pregnancy . . . . . . . . 59
Seat Belt Extender . . . . . . . . . . . . . . . . . . . . . . 59
Safety System Check . . . . . . . . . . . . . . . . . . . 60
Seat Belt Care . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Replacing Seat Belt System Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Airbag System
Airbag System . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Where Are the Airbags? . . . . . . . . . . . . . . . . 62
When Should an Airbag Inflate? . . . . . . . . 63
What Makes an Airbag Inflate? . . . . . . . . 64
How Does an Airbag Restrain? . . . . . . . . . 64
What Will You See after an Airbag
Inflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Passenger Sensing System . . . . . . . . . . . . . 66
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Adding Equipment to the Airbag-Equipped Vehicle . . . . . . . . . . . . . . 69
Airbag System Check . . . . . . . . . . . . . . . . . . . 70
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Child Restraints
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Infants and Young Children . . . . . . . . . . . . . 72
Child Restraint Systems . . . . . . . . . . . . . . . . 74
Where to Put the Restraint . . . . . . . . . . . . . 76
Lower Anchors and Tethers for Children(LATCH System) . . . . . . . . . . . . . . . . . . . . . . . 77
Replacing LATCH System Parts After a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Securing Child Restraints (With the Seat Belt in the Rear Seat) . . . . . . . . . . . . . . . . 88
Securing Child Restraints (With the Seat Belt in the Center Front Seat) . . . . . . . . 92
Securing Child Restraints (With the Seat Belt in the Front Passenger Seat) . . . . . 92
Head Restraints
{
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.
Front Seats
The vehicle's front seats have adjustable
head restraints in the outboard seating
positions.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
46 Seats and Restraints
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.
To raise or lower the head restraint, press
the button on the side of the head restraint
and pull up or push the head restraint down
and release the button.
Pull and push on 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.
Rear Head Restraints
The vehicle’s rear seat has head restraints in
the outboard seating positions that cannot
be adjusted.
The head restraint can be folded forward to
allow for better visibility when the rear seat
is unoccupied. To fold the head restraint,
press the button on the side of the head
restraint.
When an occupant is in the seat, always
return the head restraint to the upright
position until it locks into place. Push and
pull on the head restraint to make sure that
it is locked.If you are installing a child restraint in the
rear seat, see
Lower Anchors and Tethers for
Children (LATCH System) 077.
Center Headrest
The vehicle’s rear seat may be equipped
with a headrest in the center seating
position that cannot be adjusted.
If you are installing a child restraint in the
rear seat, see Lower Anchors and Tethers for
Children (LATCH System) 077.
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.