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Keys, Doors, and Windows 21
3. Remove the battery cover.
4. Pull the seal by pulling on the tab toaccess the battery.
5. Remove the old battery. Do not use a metal object.
6. Insert the new battery, positive side facing up. Replace with a CR2450 or
equivalent battery.
7. Place the seal back into the groove around the battery compartment.
8. Replace the battery cover by snapping it back into the remote key.
9. Reinsert the mechanical key.
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 054. To
view available settings from the
infotainment screen, touch Settings >
Vehicle > Comfort and Convenience.
If equipped, the automatic heated steering
wheel may also come on. See Heated
Steering Wheel 0105.
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 may run out of fuel.
The vehicle cannot be remote started if:
.The remote key is inside the vehicle or if
the key is in the ignition.
.The hood is not closed.
.There is an emission control system
malfunction and the lamp is on.
.The ignition is in any mode other
than off.
.The hazard warning flashers are on.
.The 30 minutes of engine run time have
been used.
.The vehicle is not in P (Park).
The engine will turn off during a remote
vehicle start if:
.The coolant temperature gets too high.
.The oil pressure gets low.
The remote key range may be reduced
while the vehicle is running.
Other conditions can affect the performance
of the remote key. See Remote Key015.
Starting the Engine Using Remote Start
Press
Stwice on the remote key. The turn
signal lamps will flash. The lamps flash to
confirm the request to remote start the
vehicle has been received. During the
remote start the parking lamps will remain
on as long as the engine is running.
The engine will shut off after 15 minutes or
after the remainder of the 30 minute total
running time is used, unless you stop the
remote start before engine running has
completed or the vehicle is turned on.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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46 Seats and Restraints
Seats and Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . 47
Front Seats
Seat Adjustment . . . . . . . . . . . . . . . . . . . . . . . 48
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Power Seat Adjustment . . . . . . . . . . . . . . . . 49
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . 49
Lumbar Adjustment . . . . . . . . . . . . . . . . . . . . 50
Massage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Heated and Ventilated Front Seats . . . . . 54
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . . 56
Seat Belts
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Buckle To Drive . . . . . . . . . . . . . . . . . . . . . . . . . 58
How to Wear Seat Belts Properly . . . . . . 58
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . 60
Seat Belt Use During Pregnancy . . . . . . . . 63
Seat Belt Extender . . . . . . . . . . . . . . . . . . . . . . 63
Safety System Check . . . . . . . . . . . . . . . . . . . 63
Seat Belt Care . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Replacing Seat Belt System Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Airbag System
Airbag System . . . . . . . . . . . . . . . . . . . . . . . . . 64
Where Are the Airbags? . . . . . . . . . . . . . . . . 66
When Should an Airbag Inflate? . . . . . . . . 67
What Makes an Airbag Inflate? . . . . . . . . 68
How Does an Airbag Restrain? . . . . . . . . . 68
What Will You See after an AirbagInflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Passenger Sensing System . . . . . . . . . . . . . 69
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Adding Equipment to the Airbag-Equipped Vehicle . . . . . . . . . . . . . . 73
Airbag System Check . . . . . . . . . . . . . . . . . . . 74
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Child Restraints
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Infants and Young Children . . . . . . . . . . . . . 76
Child Restraint Systems . . . . . . . . . . . . . . . . 78
Where to Put the Restraint . . . . . . . . . . . . 80
Lower Anchors and Tethers for Children(LATCH System) . . . . . . . . . . . . . . . . . . . . . . . 81
Replacing LATCH System Parts After a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Securing Child Restraints (With the Seat Belt in the Center Front Seat) . . . . . . . . 92
Securing Child Restraints (With the Seat Belt in the Rear Seat) . . . . . . . . . . . . . . . . . 92 Securing Child Restraints (With the Seat
Belt in the Front Passenger Seat) . . . . . 95

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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48 Seats and Restraints
If you are installing a child restraint in the
rear seat, seeLower Anchors and Tethers for
Children (LATCH System) 081.
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) 081.
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 049.
To adjust the lumbar support, if equipped,
see Lumbar Adjustment 050.
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.

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Seats and Restraints 49
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 049.
To adjust the lumbar support, see Lumbar
Adjustment 050. Some vehicles are equipped with a feature
that activates a vibrating pulse alert in the
driver seat to help the driver avoid crashes.
See
Advanced Driver Assistance Systems
0 252.
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 recline the seatback in a moving
vehicle.
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 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
50 Seats and Restraints
To adjust a manual seatback:1. To recline, move the seatback rearward to the desired position, then release the
lever to lock the seatback in place.
Push and pull on the seatback to make
sure it is locked.
2. To return the seatback to the upright position, lift the lever fully without
applying pressure to seatback and the
seatback will return to the upright
position.
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.
Lumbar Adjustment
To adjust the lumbar support, if equipped:
.Press and hold the front or rear of the
control to increase or decrease lumbar
support.
.If equipped, press and hold the top or
bottom of the control to raise or lower
lumbar support.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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54 Seats and Restraints
Cancel Memory Seating Recalls
.During any memory recall:
Press a power seat control
Press SET memory button
.During Manual memory recall:
Release 1, 2, or
Bmemory button
.During Auto Seat Entry Memory Recall:
Turn vehicle off
Press SET, 1, 2, or
Bmemory buttons
.During Auto Seat Exit Memory Recall:
Press SET, 1, 2, or
Bmemory buttons
Obstructions
If something has blocked the 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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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60 Seats and Restraints
Never wear the shoulder belt under both
arms or behind your back.
Always use the correct buckle for your
seating position.
Never route the lap or shoulder belt over an
armrest.
{Warning
The seat belt can be pinched if it is
routed under plastic trim on the seat,
such as trim around the rear seatback
folding handle or side airbag. In a crash,
pinched seat belts might not provide
adequate protection. Never allow seat
belts to be routed under plastic trim
pieces.
{Warning
You can be seriously injured or killed if
the shoulder belt is worn behind your
back, under your legs, or wrapped around
your neck. The shoulder belt can tighten
but cannot be loosened if it is locked. The
shoulder belt locks when it is pulled all
the way out of the retractor. It unlocks
when the shoulder belt is allowed to go
all the way back into the retractor, but it
cannot do this if it is wrapped around
you. You may have to cut the seat belt if
it is locked and tightened around you.
Lap-Shoulder Belt
All seating positions in the vehicle have a
lap-shoulder belt.
The following instructions explain how to
wear a lap-shoulder belt properly.1. Adjust the seat, if the seat is adjustable, so you can sit up straight. To see how,
see “Seats” in the Index.

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Seats and Restraints 61
2. Pick up the latch plate and pull the beltacross you. Do not let it get twisted.
The lap-shoulder belt may lock if you
pull the belt across you very quickly.
If this happens, let the belt go back
slightly to unlock it. Then pull the belt
across you more slowly.
If the shoulder portion of a passenger
belt is pulled out all the way, the child
restraint locking feature may be
engaged. See Child Restraint Systems
0 78. If this occurs, let the belt go back
all the way and start again. If the
locking feature stays engaged after
letting the belt go back to stowed position on the seat, move the seat
rearward or recline the seat until the
shoulder belt retractor lock releases.
Engaging the child restraint locking
feature in the front outboard seating
position may affect the passenger
sensing system, if equipped. See
Passenger Sensing System
069.
If the webbing locks in the latch plate
before it reaches the buckle, tilt the latch
plate flat to unlock.
3. Push the latch plate into the buckle until
it clicks.
Pull up on the latch plate to make sure
it is secure. If the belt is not long
enough, see Seat Belt Extender 063.
Position the release pushbutton on the
buckle so that the seat belt could be
quickly unbuckled if necessary.
If equipped with a shoulder belt height
adjuster, move it to the height that is
right for you. See "Shoulder Belt Height
Adjuster" later in this section for
instructions on use and important safety
information.