seats GMC SIERRA 2021 User Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
38 Keys, Doors, and Windows
Reverse Tilt Mirrors
If equipped with reverse tilt mirrors and
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) may move from their tilted
position when:
.The vehicle is shifted out of R (Reverse),
or remains in R (Reverse) for about
30 seconds.
.The vehicle is turned off.
.The vehicle is driven in R (Reverse) above
a set speed.
To turn this feature on or off, see Vehicle
Personalization 0131.
Interior Mirrors
Interior Rearview Mirrors
Adjust the rearview mirror for a clear view
of the area behind your vehicle.
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
If equipped, the mirror will automatically
reduce the glare of the headlamps from
behind. The dimming feature comes on each
time the vehicle is started.
Rear Camera Mirror
If equipped, this automatic dimming mirror
provides a wide angle camera view of the
area behind the vehicle.
Pull the tab to turn on the display. Push the
tab to turn it off. When off the mirror is
automatic dimming. Adjust the mirror for a
clear view of the area behind the vehicle
while the display is off.

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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 47
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 048.
To adjust the lumbar support, if equipped,
see Lumbar Adjustment 048.
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.
Pull the strap on the side of the center
seatback to fold the center seatback. Do not
use the center seatback as a seating position
when the seatback is folded down.
To raise the seatback, push the seatback
rearward until it locks in the upright
position. Push and pull on the seatback to
make sure it is locked.
Power Seat Adjustment
To adjust a power seat, if equipped:
.Move the seat forward or rearward by
sliding the control forward or rearward.
.Raise or lower the front part of the seat
cushion by moving the front of the
control up or down.
.Raise or lower the seat by moving the
rear of the control up or down.
To adjust the seatback, see Reclining
Seatbacks 048.
To adjust the lumbar support, see Lumbar
Adjustment 048.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
48 Seats and Restraints
Some vehicles are equipped with a feature
that activates a vibrating pulse alert in the
driver seat to help the driver avoid crashes.
SeeDriver Assistance Systems 0265.
Lumbar Adjustment
Power Lumbar
To adjust the 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.
Reclining Seatbacks
{Warning
Sitting in a reclined position when the
vehicle is in motion can be dangerous.
Even when buckled up, the seat belts
cannot do their job.
The shoulder belt will not be against
your body. Instead, it will be in front of
you. In a crash, you could go into it,
receiving neck or other injuries.
The lap belt could go up over your
abdomen. The belt forces would be there,
not at your pelvic bones. This could cause
serious internal injuries.
For proper protection when the vehicle is
in motion, have the seatback upright.
Then sit well back in the seat and wear
the seat belt properly.
Do not have a seatback reclined if the
vehicle is moving.
Manual Reclining Seatbacks
{Warning
If either seatback is not locked, it could
move forward in a sudden stop or crash.
That could cause injury to the person
sitting there. Always push and pull on
the seatbacks to be sure they are locked.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 49
To adjust a manual seatback:1. Lift the lever. The seatback will automatically fold
forward.
2. To recline, move the seatback rearward to the desired position, then release the
lever to lock the seatback in place.
3. Push and pull on the seatback to make sure it is locked.
To return the seatback to the upright
position: 1. Lift the lever fully without applying pressure to the seatback, and the
seatback will return to the upright
position. 2. Push and pull on the seatback to make
sure it is locked.
Power Reclining Seatbacks
To recline a power seatback, if equipped:
.Tilt the top of the control rearward to
recline.
.Tilt the top of the control forward to
raise.
Memory Seats
If equipped, memory seats allow two drivers
to save and recall their unique seat positions
for driving the vehicle, and a shared exit
position for getting out of the vehicle. Other
feature positions may also be saved, such as
power mirrors, if equipped. Memory
positions are linked to RKE transmitter 1 or 2
for automatic memory recalls.
Before saving, adjust all available memory
feature positions. Turn the vehicle on and
then press and release SET; a beep will
sound. Then immediately press and hold 1,
2, or
B(Exit) until two beeps sound. To
manually recall these positions, press and

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
50 Seats and Restraints
hold 1, 2, orBuntil the saved position is
reached. Follow the instructions under
“Saving Memory Positions.”
The vehicle identifies the current driver’s RKE
transmitter number (1–8). See Remote
Keyless Entry (RKE) System Operation (Key
Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013. Only RKE
transmitters 1 and 2 can be used for
automatic memory recalls. A Driver
Information Center (DIC) welcome message
indicating the transmitter number may
display for the first few ignition cycles
following a transmitter change. For Seat
Entry Memory to work properly, save the
positions to the memory button (1 or 2)
matching the RKE transmitter number
displayed in the DIC welcome message.
Carry the linked RKE transmitter when
entering the vehicle.
Vehicle Personalization Settings
.To have the Seat Entry Memory
movement begin when the vehicle is
started, select the Settings menu, then
Vehicle, then Seating Position, and then
Seat Entry Memory. Select On or Off. See
“Seat Entry Memory” later in this section.
.To begin Seat Exit Memory movement
when the vehicle is turned off and the
driver door is opened, or when the vehicle
is turned off with the driver door already
opened, select the Settings menu, then
Vehicle, then Seating Position, and then
Seat Exit Memory. Select On or Off. See
“Seat Exit Memory”later in this section.
.SeeVehicle Personalization 0131 for
additional setting information.
Identifying Driver Number
To identify the driver number: 1. Move your RKE transmitter away from the vehicle.
2. Start the vehicle with another key or RKE transmitter. The DIC should display the
driver number for the other RKE
transmitter. Turn the vehicle off and
remove the key or RKE transmitter from
the vehicle.
3. Start the vehicle with the initial key or RKE transmitter. The DIC should display
the driver number of your RKE
transmitter.
Saving Memory Positions
Read these instructions completely before
saving memory positions. To save preferred driving positions 1 and 2:
1. Turn the vehicle on or to ACC/ ACCESSORY.
A DIC welcome message may indicate
driver number 1 or 2.
2. Adjust all available memory features to the desired driving position.
3. Press and release SET; a beep will sound.
4. Immediately press and hold the 1 or 2 memory button matching the above
DIC welcome message until two beeps
sound.
If too much time passes between
releasing SET and pressing 1, the
memory position will not be saved and
two beeps will not sound. Repeat
Steps 3 and 4.
1 or 2 corresponds to the driver number.
See “Identifying Driver Number”
previously in this section.
5. Repeat Steps 1–4 for a second driver using 1 or 2. RKE transmitters 3–8 will
not save memory positions.
To save the position for
Band Seat Exit
Memory features, repeat Steps 1–4 using
B. This saves the position for getting out
of the vehicle.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 51
Save preferred memory feature positions to
both 1 and 2 if you are the only driver.
Manually Recalling Memory Positions
Press and hold 1, 2, or
Bto recall the
previously saved memory positions if you
are driver 1 or 2 identified in the DIC
welcome message.
To stop Manual Memory recall movement,
release 1, 2, or
Bor press any of the
following controls:
.Power seat
.Memory SET
.Power mirror, with the driver or
passenger side mirror selected
Manual Memory recall movement for 1, 2,
or
Bbuttons may be initiated and may
complete to the saved memory position if
the vehicle is in or out of P (Park).
Seat Entry Memory
The vehicle identifies the number of the
current driver’s RKE transmitter (1–8). See
Remote Keyless Entry (RKE) System
Operation (Key Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013. If the RKE
transmitter is 1 or 2, and Seat Entry Memory
is enabled in vehicle personalization, the positions saved to the same memory button
number 1 or 2 are automatically recalled
when the vehicle is turned on, or turned
from off to ACC/ACCESSORY. RKE
transmitters 3–8 will not provide automatic
memory recalls.
To turn Seat Entry Memory on or off, see
“Vehicle Personalization Settings”
previously
in this section and Vehicle Personalization
0 131.
The shift lever must be in P (Park) to start
Seat Entry Memory. Seat Entry Memory
recall will complete if the vehicle is shifted
out of P (Park) prior to reaching the saved
memory position.
To stop Seat Entry Memory recall
movement, turn the vehicle off or press any
of the following controls:
.Power seat
.Memory SET, 1, 2, orB
.Power mirror, with the driver or
passenger side mirror selected
If the saved memory seat position does not
automatically recall or recalls to the wrong
positions, the driver’s RKE transmitter
number (1 or 2) may not match the memory
button number that positions were saved to. Try storing the position to the other
memory button or try the other RKE
transmitter.
Seat Exit Memory
Seat Exit Memory is not linked to an RKE
transmitter. The position saved to
Bis
used for all drivers. To turn Seat Exit
Memory on or off, see "Vehicle
Personalization Settings" previously in this
section and Vehicle Personalization 0131.
If turned on, the position saved to
Bis
automatically recalled when one of the
following occurs:
.The vehicle is turned off and the driver
door is opened within a short time.
.The vehicle is turned off with the driver
door open.
To stop Seat Exit Memory movement, press
any of the following memory controls:
.Power seat
.Memory SET, 1, 2, orB
.Power mirror, with the driver or
passenger side mirror selected

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
52 Seats and Restraints
Obstructions
If something has blocked the driver seat
while recalling a memory position, the recall
may stop. Remove the obstruction and try
the recall again. If the memory position still
does not recall, see your dealer.
Heated and Ventilated Front
Seats
{Warning
If temperature change or pain to the skin
cannot be felt, the seat heater may cause
burns. To reduce the risk of burns, use
care when using the seat heater,
especially for long periods of time. Do
not place anything on the seat that
insulates against heat, such as a blanket,
cushion, cover, or similar item. This may
cause the seat heater to overheat. An
overheated seat heater may cause a burn
or may damage the seat.Heated and Ventilated Seat Buttons Shown,Heated Seat Buttons Similar
If equipped, the buttons are on the center
stack. To operate, the engine must be
running.
Press
Ior+to heat the driver or
passenger seatback only.
Press
Jorzto heat the driver or
passenger seat cushion and seatback.
Press
Cor{to ventilate the driver or
passenger seat.
The indicator light on the button comes on
when this feature is on. Press the button once for the highest
setting. With each press of the button, the
seat will change to the next lower setting,
and then to the off setting. The indicator
lights next to the buttons indicate three for
the highest setting and one for the lowest.
If the heated seats are on high for an
extended time, their level may automatically
be lowered.
Auto Heated Seats
When the vehicle is on, this feature will
automatically activate the heated seats at
the level required by the vehicle’s interior
temperature. The active high, medium, low,
or off heated seat level will be indicated by
the manual heated seat buttons on the
center stack. Use the manual heated seat
buttons on the center stack to turn auto
heated seats off. If the passenger seat is
unoccupied, the auto heated seats feature
will not activate that seat. The auto heated
seats feature can be programmed to always
be enabled when the vehicle is on. See
Vehicle Personalization
0131.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 53
Remote Start Heated and Ventilated Seats
If equipped, the heated seats will turn on
automatically during a remote start if it is
cold outside and the ventilated seats will
turn on automatically if it is hot outside.
If equipped, the heated steering wheel will
turn on automatically during a remote start
if it is cold outside. The heated and
ventilated seat indicators and heated
steering wheel indicator may not come on
during this operation.
The heated and ventilated seats and heated
steering wheel may cancel when the vehicle
is started. These features can be manually
selected after the ignition is turned on.
The temperature performance of an
unoccupied seat may be reduced. This is
normal.
The heated or ventilated seats will not turn
on during a remote start unless they are
enabled in vehicle personalization. See
Remote Vehicle Start020 and
Vehicle Personalization 0131.Rear Seats
Rear Seat Reminder
If equipped, the message REAR SEAT
REMINDER LOOK IN REAR SEAT displays
under certain conditions indicating there
may be an item or passenger in the rear
seat. Check before exiting the vehicle.
This feature will activate when a second row
door is opened while the vehicle is on or up
to 10 minutes before the vehicle is turned
on. There will be an alert when the vehicle
is turned off. The alert does not directly
detect objects in the rear seat; instead,
under certain conditions, it detects when a
rear door is opened and closed, indicating
that there may be something in the
rear seat.
The feature is active only once each time
the vehicle is turned on and off, and will
require reactivation by opening and closing
the second row doors. There may be an
alert even when there is nothing in the rear
seat; for example, if a child entered the
vehicle through the rear door and left the
vehicle without the vehicle being shut off.
The feature can be turned on or off. See
Vehicle Personalization 0131.
Folding the Rear Seat Cushion
Either side of the rear seat cushion can be
folded up for added cargo space.
Caution
Folding a rear seat with the seat belts
still fastened may cause damage to the
seat or the seat belts. Always unbuckle
the seat belts and return them to their
normal stowed position before folding a
rear seat.
Make sure that nothing is on the seat
cushion.
To fold the seat, slowly pull the seat
cushion up.