warning GMC SIERRA 2023 Owners Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Keys, Doors, and Windows . . . . . . . . . . . . . . . 8
Seats and Restraints . . . . . . . . . . . . . . . . . . . . 49
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Instruments and Controls . . . . . . . . . . . . . . 104
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Infotainment System . . . . . . . . . . . . . . . . . . . 148
Climate Controls . . . . . . . . . . . . . . . . . . . . . . . 196
Driving and Operating . . . . . . . . . . . . . . . . . 203
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
Service and Maintenance . . . . . . . . . . . . . . . 384
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . 392
Customer Information . . . . . . . . . . . . . . . . . . 396
Reporting Safety Defects . . . . . . . . . . . . . . . 404
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
Connected Services . . . . . . . . . . . . . . . . . . . . . 413
Index . . . . . . . . . . . . . . . . . . . . . . . . . . 416
Introduction
California Proposition 65 Warning
Litho in U.S.A.
Part No. 84883882 A First Printing©2022 General Motors LLC. All Rights Reserved.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
2 Introduction
Introduction
The names, logos, emblems, slogans, vehicle
model names, and vehicle body designs
appearing in this manual including, but not
limited to, GM, the GM logo, GMC, the GMC
Truck Emblem, SIERRA, and DENALI are
trademarks and/or service marks of General
Motors LLC, its subsidiaries, affiliates,
or licensors.
For vehicles first sold in Canada, substitute
the name“General Motors of Canada
Company” for GMC Division wherever it
appears in this manual.
This manual describes features that may or
may not be on the vehicle because of
optional equipment that was not purchased
on the vehicle, model variants, country
specifications, features/applications that may
not be available in your region, or changes
subsequent to the printing of this owner’s
manual, including changes in standard or
optional content. If the vehicle has the Duramax diesel
engine, see the Duramax diesel supplement
for additional and specific information on
this engine.
Refer to the purchase documentation
relating to your specific vehicle to confirm
the features.
Keep this manual in the vehicle for quick
reference.
Canadian Vehicle Owners
A French language manual can be obtained
from your dealer, at www.helminc.com,
or from:
Propriétaires Canadiens
On peut obtenir un exemplaire de ce guide
en français auprès du concessionnaire ou à
l'adresse suivante:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
USA
Using this Manual
To quickly locate information about the
vehicle, use the Index in the back of the
manual. It is an alphabetical list of what is
in the manual and the page number where
it can be found.
Danger, Warning, and Caution
Warning messages found on vehicle labels
and in this manual describe hazards and
what to do to avoid or reduce them.
{Danger
Danger indicates a hazard with a high
level of risk which will result in serious
injury or death.
{Warning
Warning indicates a hazard that could
result in injury or death.
Caution
Caution indicates a hazard that could
result in property or vehicle damage.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Introduction 3
A circle with a slash through it is a safety
symbol which means“Do not,” “Do not do
this,” or“Do not let this happen.”
Symbols
The vehicle has components and labels that
use symbols instead of text. Symbols are
shown along with the text describing the
operation or information relating to a
specific component, control, message, gauge,
or indicator.
M:Shown when the owner’s manual has
additional instructions or information.
*: Shown when the service manual has
additional instructions or information.
0: Shown when there is more information
on another page — “see page.” Vehicle Symbol Chart
Here are some additional symbols that may
be found on the vehicle and what they
mean. See the features in this manual for
information.
u:
Air Conditioning System
G:Air Conditioning Refrigerant Oil
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
$:Brake System Warning Light
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

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
6 Introduction
1. Tow/Haul Mode (On Some Models). SeeDriver Mode Control 0243.
Automatic Transfer Case Control (If
Equipped). See Four-Wheel Drive 0234.
Driver Mode Control 0243 (If Equipped).
2. Air Vents 0201.
3. Head-Up Display (HUD) 0132 (If
Equipped).
4. Turn Signal Lever. See Turn and
Lane-Change Signals 0143.
Windshield Wiper/Washer 0106.
5. Instrument Cluster 0111.
6. Shift Lever. See Automatic Transmission
0 230.
Range Selection Mode. See Manual Mode
0 232.
7. Light Sensor. See Automatic Headlamp
System 0141.
8. Infotainment Controls. See Overview
0 149.
9. Climate Control Systems 0196 (If
Equipped).
Dual Automatic Climate Control System
0 197 (If Equipped).
10. Heated and Ventilated Front Seats 056
(If Equipped). 11.XPark Assist Switch (If Equipped). See
Assistance Systems for Parking or Backing
0 248.
5Power Release Tailgate (If
Equipped). See Tailgate026.
|Hazard Warning Flashers 0142.
gTraction Control/Electronic Stability
Control 0241.
-DC/AC Switch. See Power Outlets
0 107.
@Lane Departure Warning (LDW) 0262
(If Equipped).
5Hill Descent Control Switch (If
Equipped). See Hill Descent Control (HDC)
0 242.
jPower Assist Steps 033 (If
Equipped).
LExpress Window Down Button (If
Equipped). See Power Windows 044.
Tow/Haul Mode 0234 (On Some
Models).
Exhaust Brake (If Equipped). See Duramax
Diesel Supplement.
Power Take-Off (PTO) (If Equipped). See
Duramax Diesel Supplement. 12. Power Outlet (Alternating Current) (If
Equipped). See Power Outlets0107.
13. Power Outlets 0107.
14. USB Port 0158.
15. Wireless Charging 0109 (If Equipped).
16. Trailer Brake Control Panel (If Equipped). See“Integrated Trailer Brake Control
System” underTowing Equipment 0276.
17. ENGINE START/STOP. See Ignition
Positions (Key Access) 0221 or
Ignition Positions (Keyless Access) 0223.
18. Steering Wheel Controls 0151 (If
Equipped).
Driver Information Center (DIC) Controls.
See Driver Information Center (DIC) (Base
Level) 0128 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0130.
19. Horn 0106.
20. Hood Release. See Hood0303.
21. Steering Wheel Adjustment 0105 (Out
of View).
22. Cruise Control 0244.
Forward Collision Alert (FCA) System
0 257 (If Equipped).
Heated Steering Wheel 0105 (If
Equipped).

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
8 Keys, Doors, and Windows
Keys, Doors, and
Windows
Keys and Locks
Keys (Key Access) . . . . . . . . . . . . . . . . . . . . . . . 8
Keys (Keyless Access) . . . . . . . . . . . . . . . . . . . 11
Remote Keyless Entry (RKE) System . . . . 12
Remote Keyless Entry (RKE) SystemOperation (Key Access) . . . . . . . . . . . . . . . . 12
Remote Keyless Entry (RKE) System Operation (Keyless Access) . . . . . . . . . . . . 14
Remote Vehicle Start . . . . . . . . . . . . . . . . . . . 22
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Power Door Locks . . . . . . . . . . . . . . . . . . . . . . 24
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 24
Automatic Door Locks . . . . . . . . . . . . . . . . . . 24
Lockout Protection . . . . . . . . . . . . . . . . . . . . . . 25
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Transporting Items That Can Catch Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Power Assist Steps . . . . . . . . . . . . . . . . . . . . . 33
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . 34
Vehicle Alarm System . . . . . . . . . . . . . . . . . . 34
Steering Column Lock . . . . . . . . . . . . . . . . . . . 35 Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Immobilizer Operation . . . . . . . . . . . . . . . . . . 35
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 36
Manual Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 37
Trailer-Tow Mirrors . . . . . . . . . . . . . . . . . . . . . 37
Power Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 39
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 39
Automatic Dimming Mirror . . . . . . . . . . . . . 39
Blind Spot Mirrors . . . . . . . . . . . . . . . . . . . . . . 39
Reverse Tilt Mirrors . . . . . . . . . . . . . . . . . . . . 40
Interior Mirrors
Interior Rearview Mirrors . . . . . . . . . . . . . . . 40
Manual Rearview Mirror . . . . . . . . . . . . . . . . 41
Automatic Dimming Rearview Mirror . . . 41
Rear Camera Mirror . . . . . . . . . . . . . . . . . . . . . 41
Truck Bed Camera Rearview Mirror . . . . . 43
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Manual Windows . . . . . . . . . . . . . . . . . . . . . . 44
Power Windows . . . . . . . . . . . . . . . . . . . . . . . . 44
Rear Windows . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Sun Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Keys and Locks
Keys (Key Access)
{Warning
Leaving children in a vehicle with the
ignition key is dangerous and children or
others could be seriously injured or killed.
They could operate the power windows
or other controls or make the vehicle
move. The windows will function with
the keys in the ignition, 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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Keys, Doors, and Windows 9
{Warning
If the key is unintentionally rotated while
the vehicle is running, the ignition could
be moved out of the RUN position. This
could be caused by heavy items hanging
from the key ring, or by large or long
items attached to the key ring that could
be contacted by the driver or steering
wheel. If the ignition moves out of the
RUN position, the engine will shut off,
braking and steering power assist may be
impacted, and airbags may not deploy.
To reduce the risk of unintentional
rotation of the ignition key, do not
change the way the ignition key and
Remote Keyless Entry (RKE) transmitter,
if equipped, are connected to the
provided key rings.
The ignition key and key rings, and RKE
transmitter, if equipped, are designed to
work together as a system to reduce the
risk of unintentionally moving the key out
of the RUN position. The ignition key has a
small hole to allow attachment of the
provided key ring. It is important that any replacement ignition keys have a small hole.
See your dealer if a replacement key is
required.
The combination and size of the rings that
came with your keys were specifically
selected for your vehicle. The rings are
connected to the key like two links of a
chain to reduce the risk of unintentionally
moving the key out of the RUN position. Do
not add any additional items to the ring
attached to the ignition key. Attach
additional items only to the second ring,
and limit added items to a few essential
keys or small, light items no larger than an
RKE transmitter.
Interference from radio-frequency
identification (RFID) tags may prevent the
key from starting the vehicle. Keep RFID
tags away from the key when starting the
vehicle.
The key is used for the ignition, all door
locks, and the glove box.
If equipped with memory seats, keys 1 and 2
are linked to seating positions of memory 1
or 2. See
Memory Seats 053.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Keys, Doors, and Windows 11
Keys (Keyless Access)
{Warning
Leaving children in a vehicle with an
ignition key or Remote Keyless Entry
(RKE) transmitter is dangerous and
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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Keys, Doors, and Windows 13
To view available settings from the
infotainment screen, touch Settings >
Vehicle > Remote Lock, Unlock, Start.
Pressing
Kon the RKE transmitter disarms
the alarm system. See Vehicle Alarm System
0 34.
If equipped with remote mirror folding,
pressing and holding
Kfor one second will
unfold the mirrors, if enabled. To view
available settings for this feature, touch the
Settings icon on the infotainment home
page. Select “Vehicle”to display the list of
available options and select “Comfort and
Convenience”.
Press and hold
Kto remotely open the
windows, if enabled. To view available
settings from the infotainment screen, touch
Settings > Vehicle > Remote Lock, Unlock,
Start.
x: Press twice quickly to release the
tailgate, if equipped.
7: Press and release to initiate the vehicle
locator. The turn signal lamps flash and the
horn sounds three times. Press and hold
7for more than
three seconds to activate the panic alarm.
The turn signal lamps flash and the horn
sounds repeatedly for 30 seconds. The alarm
turns off when the ignition is turned on or
7is pressed again. The ignition must be off
for the panic alarm to work.
Programming Transmitters to the Vehicle
Only RKE transmitters programmed to this
vehicle will work. If a transmitter is lost or
stolen, a replacement can be purchased and
programmed through your dealer. Each
vehicle can have up to eight transmitters
programmed to it. See your dealer for
transmitter programming.
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).
Caution
When replacing the battery, do not touch
any of the circuitry on the transmitter.
Static from your body could damage the
transmitter.
Caution
Always replace the battery with the
correct type. Replacing the battery with
an incorrect type could potentially create
a risk of battery explosion. Dispose of
used batteries according to instructions
and local laws. Do not attempt to burn,
crush, or cut the used battery, and avoid
exposing the battery to environments
with extremely low air pressures or high
temperatures.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Keys, Doors, and Windows 21
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).
Caution
When replacing the battery, do not touch
any of the circuitry on the transmitter.
Static from your body could damage the
transmitter.
Caution
Always replace the battery with the
correct type. Replacing the battery with
an incorrect type could potentially create
a risk of battery explosion. Dispose of
used batteries according to instructions
and local laws. Do not attempt to burn,
crush, or cut the used battery, and avoid
exposing the battery to environments
with extremely low air pressures or high
temperatures.
Caution
If the RKE transmitter is not reassembled
properly, liquids could enter the housing
and damage the circuitry, resulting in an
RKE transmitter malfunction and/or
failure. To prevent damage, always follow
the steps for RKE transmitter reassembly
in this manual to ensure the transmitter
is sealed properly whenever the RKE
transmitter is opened.
Replace the battery in the transmitter soon
if the DIC displays REPLACE BATTERY IN
REMOTE KEY. To replace the battery:
1. Press the button on the RKE transmitter
to remove the key. Never pull the key
out without pressing the button.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
22 Keys, Doors, and Windows
2. Insert a flat, thin object in the center ofthe transmitter to separate and remove
the back cover.
3. Lift the battery with a flat object.
4. Remove the battery.
5. Insert the new battery, positive sidetoward the back cover. Replace with a
CR2032 or equivalent battery.
6. Ensure that the silicone mat is correctly positioned with no gaps or wrinkles.
7. Set transmitter button side down on a hard surface and press the other half
straight down to force the halves
together.
8. Insert the key back into the RKE transmitter.
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 056. To
view available settings for this feature,
touch the Settings icon on the infotainment
home page. Select “Vehicle”to display the
list of available options and select “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 RKE transmitter 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.
.Two remote starts or a remote start with
an extension 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 RKE transmitter range may be reduced
while the vehicle is running.
Other conditions can affect the performance
of the transmitter. See Remote Keyless Entry
(RKE) System 012.
Starting the Engine Using Remote Start
1. Press and release
Q.
2. Immediately press and hold
/until the
turn signal lamps flash or for at least
four seconds.
When the vehicle starts, the parking
lamps will turn on. The doors will be
locked and the climate control system
may come on.