GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
92 Seats and Restraints
1. Press both buttons on the head restraintor headrest posts at the same time, and
pull up on the head restraint or
headrest.
2. Store the head restraint or headrest in a secure place.
3. When the child restraint is removed, reinstall the head restraint or headrest
before the seating position is used.
{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. To reinstall the head restraint or headrest:
1. Insert the head restraint or headrest
posts into the holes in the top of the
seatback. The notches on the posts must
face the driver side of the vehicle.
2. Push the head restraint or headrest down.
3. Try to move the head restraint or headrest to make sure that it is locked in
place.
Replacing LATCH System Parts
After a Crash
{Warning
A crash can damage the LATCH system in
the vehicle. A damaged LATCH system
may not properly secure the child
restraint, resulting in serious injury or
even death in a crash. To help make sure
the LATCH system is working properly
after a crash, see your dealer to have the
system inspected and any necessary
replacements made as soon as possible.
If the vehicle has the LATCH system and it
was being used during a crash, new LATCH
system parts may be needed.
New parts and repairs may be necessary
even if the LATCH system was not being
used at the time of the crash.
Securing Child Restraints (With
the Seat Belt in the Rear Seat)
When securing a child restraint with the
seat belts in a rear seat position, study the
instructions that came with the child
restraint to make sure it is compatible with
this vehicle.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
94 Seats and Restraints
5. Pull the shoulder belt all the way out ofthe retractor to set the lock. When the
retractor lock is set, the belt can be
tightened but not pulled out of the
retractor.6. To tighten the belt, push down on thechild restraint, pull the shoulder portion
of the belt to tighten the lap portion of
the belt, and feed the shoulder belt back
into the retractor. When installing a
forward-facing child restraint, it may be
helpful to use your knee to push down
on the child restraint as you tighten
the belt.
Try to pull the belt out of the retractor
to make sure the retractor is locked.
If the retractor is not locked, repeat
Steps 5 and 6. 7. For forward-facing child restraints, attach
and tighten the top tether to the top
tether anchor (loop). Refer to the child
restraint instructions, the vehicle LATCH
anchor weight limits, and instructions
listed in Lower Anchors and Tethers for
Children (LATCH System) 082.
8. Before placing a child in the child restraint, make sure it is securely held in
place. To check, grasp the child restraint
at the seat belt path and attempt to
move it side to side and back and forth.
When the child restraint is properly
installed, there should be no more than
2.5 cm (1 in) of movement.
To remove the child restraint, unbuckle the
vehicle seat belt and let it return to the
stowed position. If the top tether is attached
to a top tether anchor, disconnect it.
Reinstall the head restraint or headrest
before the seating position is used. See
“Head Restraint or Headrest Removal and
Reinstallation” underLower Anchors and
Tethers for Children (LATCH System) 082 for
additional information on installing the
headrest properly.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 95
Crew Cab
1. Put the child restraint on the seat.
2. Pick up the latch plate and run the lapand shoulder portions of the vehicle seat
belt through or around the child
restraint. Ensure the seat belt webbing is
routed as directly as possible and is not
caught on seat handles or plastic trim.
The child restraint instructions will show
you how.
3. Push the latch plate into the buckle untilit clicks.
Position the release button on the
buckle, away from the child restraint, so
that the seat belt could be quickly
unbuckled if necessary. There must not be direct contact of the
child restraint to the push button.
4. Pull the shoulder belt all the way out of
the retractor to set the lock. When the
retractor lock is set, the belt can be
tightened but not pulled out of the
retractor.
5. To tighten the belt, push down on thechild restraint, pull the shoulder portion
of the belt to tighten the lap portion of
the belt, and feed the shoulder belt back
into the retractor. When installing a
forward-facing child restraint, it may be
helpful to use your knee to push down
on the child restraint as you tighten
the belt.
Try to pull the belt out of the retractor
to make sure the retractor is locked.
If the retractor is not locked, repeat
Steps 4 and 5.
6. If the child restraint has a top tether, follow the child restraint manufacturer's
instructions regarding the use of the top
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
98 Seats and Restraints
Position the release button on the
buckle, away from the child restraint, so
that the seat belt could be quickly
unbuckled if necessary.
5. Pull the shoulder belt all the way out ofthe retractor to set the lock. When the
retractor lock is set, the belt can be
tightened but not pulled out of the
retractor.
6. To tighten the belt, push down on thechild restraint, pull the shoulder portion
of the belt to tighten the lap portion of
the belt, and feed the shoulder belt back
into the retractor.
There must be finger clearance between
the push button and the child restraint.
If there is not clearance between the
buckle push button and the child
restraint, move the seat upward and
repeat prior installation steps. Otherwise
secure the child restraint in a rear seat.
When installing a forward-facing child
restraint, it may be helpful to use your
knee to push down on the child restraint
as you tighten the belt. Try to pull the belt out of the retractor
to make sure the retractor is locked.
If the retractor is not locked, repeat
Steps 5 and 6.
7. If the vehicle does not have a rear seat and the child restraint manufacturer
recommends using a top tether anchor,
attach the top tether to the top tether
anchor. Refer to the instructions that
came with the child restraint and to
Lower Anchors and Tethers for Children
(LATCH System) 082.
8. Before placing a child in the child restraint, make sure it is securely held in
place. To check, grasp the child restraint
at the seat belt path and attempt to
move it side to side and back and forth.
When the child restraint is properly
installed, there should be no more than
2.5 cm (1 in) of movement.
If the airbag is off, the OFF indicator in the
passenger airbag status indicator will come
on and stay on when the vehicle is started.
If a child restraint has been installed and
the ON indicator is lit, see “If the On
Indicator Is Lit for a Child Restraint” under
Passenger Sensing System 070.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Storage 101
Underseat Storage
There may be storage under the rear
passenger seat. Lift up on the seat bench to
access. Push the seat bench toward the floor
to close.
Rear Storage
There may be storage in the rear seat. Pull
the tab to access.
Push the storage door to close. The storage
door must be closed before installing child
restraints.
Center Console Storage
Bench Seat
Pull the strap on the side of the center
seatback to access the storage area and
cupholders. 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.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
256 Driving and Operating
.The accessory trailer camera(s) are not
installed according to the installation
instructions.
A feature may be unavailable or not
activating as expected if:
.The customization is disabled. Check the
customization settings where applicable.
.The accessory trailer cameras are
swapped at the hitch connector. Ensure
that the accessory camera(s) are
connected to the correct camera input.
A view may switch automatically if:
.The vehicle is shifted to another gear.
Park Assist
If the vehicle has Rear Park Assist (RPA) or
Front and Rear Park Assist (FRPA), as the
vehicle moves at speeds of less than 8 km/h
(5 mph) the sensors on the bumpers may
detect objects up to 1.2 m (4 ft) in front and
2.5 m (8 ft) behind the vehicle within a zone
25 cm (10 in) high off the ground and below
bumper level. These detection distances may
be shorter during warmer or humid weather.
Blocked sensors will not detect objects and
can also cause false detections. Keep the
sensors clean of mud, dirt, snow, ice, and
slush; and clean sensors after a car wash in
freezing temperatures.
{Warning
The Park Assist system does not detect
children, pedestrians, bicyclists, animals,
or objects located below the bumper or
that are too close or too far from the
vehicle. It is not available at speeds
greater than 8 km/h (5 mph). To prevent
injury, death, or vehicle damage, even
with Park Assist, always check the area
around the vehicle and check all mirrors
before moving forward or backing.
The instrument cluster may have a Park
Assist display with bars that show “distance
to object” and object location information
for the Front and Rear Park Assist system.
As the object gets closer, more bars light up
and the bars change color from yellow to
amber to red. When an object is first detected in the rear,
one beep will be heard from the rear,
or both sides of the Safety Alert Seat will
pulse two times. When an object is very
close
—<0.4 m (1.5 ft) in the vehicle rear or
<0.3 m (1 ft) in the vehicle front —five
beeps will sound from the rear or front
depending on object location, or both sides
of the Safety Alert Seat will pulse five times.
Beeps for FPA are higher pitched than
for RPA.
Turning the Features On or Off
PressXon the center stack to turn on or
off the Front and Rear Park Assist. The
indicator light next to the button comes on
when the features are on and turns off
when the features have been disabled.
Front and Rear Park Assist can be turned
Off, On, or On with Towbar. If Park Assist is
turned off through vehicle personalization,
the Park Assist button will be disabled. To
turn Park Assist on again, select On in
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 267
{Warning
Fuel vapors and fuel fires burn violently
and can cause injury or death.
Follow these guidelines to help avoid
injuries to you and others:
.Read and follow all the instructions on
the fuel pump island.
.Turn off the engine when refueling.
.Keep sparks, flames, and smoking
materials away from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices while
refueling.
.Do not re-enter the vehicle while
pumping fuel.
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.(Continued)
Warning (Continued)
.Fuel can spray out if the fuel cap is
opened too quickly. This spray can
happen if the tank is nearly full, and is
more likely in hot weather. Open the
fuel cap slowly and wait for any hiss
noise to stop, then unscrew the cap all
the way.
Turn the fuel cap counterclockwise to
remove. Fully insert and latch the fill nozzle,
begin fueling. For models with dual fuel
tanks, the fuel gauge shows an average of
both tanks. When refueling, refuel the
primary front tank first, then add fuel to the
auxiliary rear tank.
{Warning
Overfilling the fuel tank by more than
three clicks of a standard fill nozzle may
cause:
.Vehicle performance issues, including
engine stalling and damage to the fuel
system.
.Fuel spills.
.Under certain conditions, fuel fires. Be careful not to spill fuel. Wait five seconds
after you have finished pumping before
removing the fill nozzle. Clean fuel from
painted surfaces as soon as possible. See
Exterior Care
0374. Reinstall the cap by
turning it clockwise until it clicks.
{Warning
If a fire starts while you are refueling, do
not remove the fill nozzle. Shut off the
flow of fuel by shutting off the pump or
by notifying the station attendant. Leave
the area immediately.
Caution
If a new fuel cap is needed, get the right
type of cap from your dealer. The wrong
type of fuel cap may not fit properly,
may turn on the malfunction indicator
lamp, and could damage the fuel system
and emissions system. See Malfunction
Indicator Lamp (Check Engine Light)
0 120.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
418 Index
Center ConsoleStorage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Charging System Light . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Check Engine Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Child Restraints Infants and Young Children . . . . . . . . . . . . . 77
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Securing . . . . . . . . . . . . . . . . . . . . . . . . 92, 96, 99
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Child Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . .25
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Cleaning
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
Climate Control Systems . . . . . . . . . . . . . . . . . 196
Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . 196
Dual Automatic . . . . . . . . . . . . . . . . . . . . . . . . 197
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Cluster, Instrument . . . . . . . . . . . . . . . . . . . . . . . 111
Collision Damage Repair . . . . . . . . . . . . . . . . . 402 Compartments
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Connected Services Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Connections Connected Services . . . . . . . . . . . . . . . . . . . . 413
Control Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Traction and Electronic Stability . . . . . . . 241
Control Light Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Control of a Vehicle . . . . . . . . . . . . . . . . . . . . . 205
Controls Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . . 151
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Coolant Engine Temperature Gauge . . . . . . . . . . . . . 117
Engine Temperature Warning Light . . . . 125
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196, 197
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Courtesy Transportation Program . . . . . . . . 401
Coverage Explanations . . . . . . . . . . . . . . . . . . . . 171
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Customer Assistance
Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Text Telephone (TTY) Users . . . . . . . . . . . . 398
Customer Information Publications Ordering Information . . . . . 404
Customer Satisfaction Procedure . . . . . . . . . 396
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
D
Damage Repair, Collision . . . . . . . . . . . . . . . . . 402
Danger, Warning, and Caution . . . . . . . . . . . . . .2
Dashboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Data Collection Infotainment System . . . . . . . . . . . . . . . . . . 407
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
Data Recorders, Event . . . . . . . . . . . . . . . . . . . 406
Database Coverage Explanations . . . . . . . . . . 171
Daytime Running Lamps (DRL) . . . . . . . . . . . . 141
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . . . 205
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Diagnostics Connected Services . . . . . . . . . . . . . . . . . . . . 415
Disabled Vehicle Transporting . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
Distracted Driving . . . . . . . . . . . . . . . . . . . . . . . . 204
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145