
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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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-
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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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Seats and Restraints 51
Uplevel Seat Adjustment
To adjust lumbar support, if equipped:
.Turn the Feature Select (1) to scroll to
lumbar support on the infotainment
display.
.Press Forward (5) or Rearward (3) to
adjust lumbar forward or rearward.
.Press Up (2) or Down (4) to adjust lumbar
up or down.
Bolster Support
To adjust bolster support, if equipped:
Turn the Feature Select (1) to scroll to
bolster support on the infotainment display.
Press Forward (5) or Rearward (3) to adjust
bolster support inward or outward. Upper Shoulder Support
To adjust upper shoulder support,
if equipped:
.Turn the Feature Select (1) to scroll to
upper shoulder support on the
infotainment display.
.Press Forward (5) or Rearward (3) to
adjust shoulder support forward or
rearward.
Massage
If equipped, the vehicle must be on to use
the massage feature.
To activate and adjust massage:
.Turn the Feature Select (1) to scroll to
massage on the infotainment display.
.Press Up (2) or Down (4) to adjust
massage type.
.Press Forward (5) or Rearward (3) to
adjust the intensity.
.To turn massage off or to activate
massage, press the massage On/Off
Control (6).
The massage feature will turn off after
approximately 20 minutes. Press the
massage On/Off Control (6) to restart the
massage feature.
Memory Seats

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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Seats and Restraints 55
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
30 minutes, their level will automatically be
lowered.
Auto Heated and Ventilated Seats
When the vehicle is on, this feature,
if enabled, will automatically activate the
heated or ventilated seats at the level
required by the vehicle’s interior
temperature.
The active high, medium, low, or off heated
or ventilated seat level will be indicated by
the manual heated or ventilated seat
buttons on the center stack. Use the manual
heated or ventilated seat buttons on the
center stack to turn auto heated or
ventilated seats off. If the passenger seat is
unoccupied, the auto heated or ventilated
seats feature will not activate that seat.
If equipped with a heated steering wheel,
the auto heated steering wheel activation
will follow the heated seat auto activation
and the heated wheel indicator will follow
the state of the steering wheel heat.To enable or disable auto heated or
ventilated seats, select Settings > Vehicle >
Climate and Air Quality > Auto Cooled or
Auto Heated Seats > ON or OFF.
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 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 vehicle is turned on.
The temperature performance of an
unoccupied seat may be reduced. This is
normal.
To enable or disable remote start heated or
ventilated seats, select Settings > Vehicle >
Remote Lock, Unlock, and Start > Remote
Start Auto Heat Seats or Remote Start Auto
Cool Seats > ON or OFF. See
Remote Vehicle
Start 021.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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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56 Seats and Restraints
The feature can be turned on or off. Select
Settings > Vehicle > Rear Seat Reminder >
ON or OFF.
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.
To return the seat to the normal seating
position, slowly pull the seat cushion down.
{Warning
A seat belt that is improperly routed, not
properly attached, or twisted will not
provide the protection needed in a crash.
The person wearing the belt could be
seriously injured. After restoring the seat
to the normal seating position, always
check to be sure that the seat belts are
properly routed and attached, and are
not twisted.
Heated Rear Seats
{Warning
If you cannot feel temperature change or
pain to the skin, the seat heater may
cause burns. See the Warning under
Heated and Ventilated Front Seats 054.
If available, the buttons are on the rear of
the center console. To operate, the engine
must be running.
Press
MorLto heat the left or right
outboard seat cushion. An indicator on the
climate control display appears 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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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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.

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62 Seats and Restraints
4. To make the lap part tight, pull up onthe shoulder belt.
To unlatch the belt, push the release
pushbutton on the buckle. The belt should
return to its stowed position.
Always stow the seat belt slowly. If the seat
belt webbing returns quickly to the stowed
position, the retractor may lock and cannot
be pulled out. If this happens, pull the seat
belt straight out firmly to unlock the
webbing, and then release it. If the webbing
is still locked in the retractor, see your
dealer.
Before a door is closed, be sure the seat belt
is out of the way. If a door is slammed
against a seat belt, damage can occur to
both the seat belt and the vehicle.
Shoulder Belt Height Adjuster
The vehicle may have a shoulder belt height
adjuster for the driver and front outboard
passenger positions.
Adjust the height so the shoulder portion of
the belt is on the shoulder and not falling
off of it. The belt should be close to, but not
contacting, the neck. Improper shoulder belt
height adjustment could reduce the
effectiveness of the seat belt in a crash. See
How to Wear Seat Belts Properly 058.
Push the release button to move the height
adjuster to the desired position.
After the adjuster is set to the desired
position, try to move it down without
pushing the release button to make sure it
has locked into position.
Seat Belt Pretensioners
This vehicle has seat belt pretensioners for
the front outboard occupants. Although the
seat belt pretensioners cannot be seen, they
are part of the seat belt assembly. They can
help tighten the seat belts during the early
stages of a moderate to severe frontal, near
frontal, or rear crash if the threshold
conditions for pretensioner activation are