
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-
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74 Seats and Restraints
{Warning
For up to 10 seconds after the vehicle is
turned off and the battery is
disconnected, an airbag can still inflate
during improper service. You can be
injured if you are close to an airbag
when it inflates. Avoid yellow connectors.
They are probably part of the airbag
system. Be sure to follow proper service
procedures, and make sure the person
performing work for you is qualified to
do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the vehicle's
frame, bumper system, height, front end,
or side sheet metal, may keep the airbag
system from working properly.
The operation of the airbag system can also
be affected by changing, including
improperly repairing or replacing, any parts
of the following:
.Airbag system, including airbag modules,
front or side impact sensors, sensing and
diagnostic module, or airbag wiring
.Front seats, including stitching, seams,
or zippers
.Seat belts
.Steering wheel, instrument panel,
overhead console, ceiling trim, or pillar
garnish trim
.Inner door seals, including speakers
Your dealer and the service manual have
information about the location of the airbag
modules and sensors, sensing and diagnostic
module, and airbag wiring along with the
proper replacement procedures.
In addition, the vehicle has a passenger
sensing system for the front outboard
passenger position, which includes sensors
that are part of the passenger seat. The
passenger sensing system may not operate
properly if the original seat trim is replaced
with non-GM covers, upholstery, or trim; or
with GM covers, upholstery, or trim
designed for a different vehicle. Any object,
such as an aftermarket seat heater or a
comfort-enhancing pad or device, installed
under or on top of the seat fabric, could
also interfere with the operation of the
passenger sensing system. This could either
prevent proper deployment of the passenger
airbag(s) or prevent the passenger sensing system from properly turning off the
passenger airbag(s). See
Passenger Sensing
System 070.
If the vehicle has rollover roof-rail airbags,
see Different Size Tires and Wheels 0353 for
additional important information.
If a snow plow is added to the vehicle, the
airbags should still work properly. The
airbag systems were designed to work
properly under a wide range of conditions,
including snow plowing with vehicles that
have the optional snow plow prep package
(RPO VYU). Do not change or defeat the
snow plow's “tripping mechanism.” If you
do, it can damage the snow plow and the
vehicle, and may cause an airbag
deployment.
If the vehicle must be modified because you
have a disability and have questions about
whether the modifications will affect the
vehicle's airbag system, or if you have
questions about whether the airbag system
will be affected if the vehicle is modified for
any other reason, call Customer Assistance.
See Customer Assistance Offices 0398.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
204 Driving and Operating
Trailer Towing
General Towing Information . . . . . . . . . . 268
Driving Characteristics andTowing Tips . . . . . . . . . . . . . . . . . . . . . . . . . 268
Trailer Towing . . . . . . . . . . . . . . . . . . . . . . . . . 272
Towing Equipment . . . . . . . . . . . . . . . . . . . . 276
Trailer Sway Control (TSC) . . . . . . . . . . . . . 285
Trailering App . . . . . . . . . . . . . . . . . . . . . . . . . 287
Conversions and Add-Ons
Add-On Electrical Equipment . . . . . . . . . . . 297
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Pickup Conversion to Chassis Cab . . . . . 300
Driving Information
Driving for Better Fuel Economy
Driving habits can affect fuel mileage. Here
are some driving tips to get the best fuel
economy possible:
.Set the climate controls to the desired
temperature after the engine is started,
or turn them off when not required.
.Avoid fast starts and accelerate smoothly.
.Brake gradually and avoid abrupt stops.
.Avoid idling the engine for long periods
of time.
.When road and weather conditions are
appropriate, use cruise control.
.Always follow posted speed limits or
drive more slowly when conditions
require.
.Keep vehicle tires properly inflated.
.Combine several trips into a single trip.
.Replace the vehicle's tires with the same
TPC Spec number molded into the tire's
sidewall near the size.
.Follow recommended scheduled
maintenance.
Distracted Driving
Distraction comes in many forms and can
take your focus from the task of driving.
Exercise good judgment and do not let other
activities divert your attention away from
the road. Many local governments have
enacted laws regarding driver distraction.
Become familiar with the local laws in
your area.
To avoid distracted driving, keep your eyes
on the road, keep your hands on the
steering wheel, and focus your attention on
driving.
.Do not use a phone in demanding driving
situations. Use a hands-free method to
place or receive necessary phone calls.
.Watch the road. Do not read, take notes,
or look up information on phones or
other electronic devices.
.Designate a front seat passenger to
handle potential distractions.
.Become familiar with vehicle features
before driving, such as programming
favorite radio stations and adjusting
climate control and seat settings. Program
all trip information into any navigation
device prior to driving.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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Vehicle Care 301
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 302
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 302
Accessories and Modifications . . . . . . . . . 302
Vehicle Checks
Doing Your Own Service Work . . . . . . . . 303
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Engine Compartment Overview . . . . . . . . 305
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
Engine Oil Life System . . . . . . . . . . . . . . . . 308
Automatic Transmission Fluid . . . . . . . . . 309
Engine Air Filter Life System . . . . . . . . . . 309
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . 310
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 311
Engine Overheating . . . . . . . . . . . . . . . . . . . . 313
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . 315
Engine Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Power Steering Fluid . . . . . . . . . . . . . . . . . . . 315
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Brake Pad Life System . . . . . . . . . . . . . . . . . 317
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
Battery - North America . . . . . . . . . . . . . . . 319
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 321
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Noise Control System . . . . . . . . . . . . . . . . . . 321
Automatic Transmission Shift Lock
Control Function Check (Mechanical
Shifter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Wiper Blade Replacement . . . . . . . . . . . . . 323
Glass Replacement . . . . . . . . . . . . . . . . . . . . . 323
Windshield Replacement . . . . . . . . . . . . . . 324
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 325
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 325
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 325
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Headlamps, Front Turn Signal, Sidemarker, and Parking Lamps . . . . . . 325
Taillamps, Turn Signal, Stoplamps, and Back-Up Lamps . . . . . . . . . . . . . . . . . . . . . . 326
Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp . . . . . . . . . . . . 327
License Plate Lamp . . . . . . . . . . . . . . . . . . . . 327
Electrical System
Electrical System Overload . . . . . . . . . . . . . 327
Fuses and Circuit Breakers . . . . . . . . . . . . . 329
Engine Compartment Fuse Block . . . . . . 329 Instrument Panel Fuse Block (Left) . . . . . 333
Instrument Panel Fuse Block (Right) . . . 334
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 338
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . . 338
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 338
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 339
Tire Terminology and Definitions . . . . . 340
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 342
Tire Pressure Monitor System . . . . . . . . . 343
Tire Pressure Monitor Operation . . . . . . 344
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 348
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 349
When It Is Time for New Tires . . . . . . . . . 351
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . 352
Different Size Tires and Wheels . . . . . . . . 353
Uniform Tire Quality Grading . . . . . . . . . . 353
Wheel Alignment and Tire Balance . . . . 354
Wheel Replacement . . . . . . . . . . . . . . . . . . . 354
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 356
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . 367
Jump Starting
Jump Starting - North America . . . . . . . . 367

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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338 Vehicle Care
Warning (Continued)
.Do not spin the tires in excess of
56 km/h (35 mph) on slippery
surfaces such as snow, mud, ice,
etc. Excessive spinning may cause
the tires to explode.
All-Season Tires
This vehicle may come with all-season tires.
These tires are designed to provide good
overall performance on most road surfaces
and weather conditions. Original equipment
tires designed to GM's specific tire
performance criteria have a TPC specification
code molded onto the sidewall. Original
equipment all-season tires can be identified
by the last two characters of this TPC code,
which will be“MS.”
Consider installing winter tires on the
vehicle if frequent driving on snow or
ice-covered roads is expected. All-season tires
provide adequate performance for most
winter driving conditions, but they may not
offer the same level of traction or
performance as winter tires on snow or
ice-covered roads. See Winter Tires0338.
Winter Tires
This vehicle was not originally equipped
with winter tires. Winter tires are designed
for increased traction on snow and
ice-covered roads. Consider installing winter
tires on the vehicle if frequent driving on ice
or snow covered roads is expected. See your
dealer for details regarding winter tire
availability and proper tire selection. Also,
see Buying New Tires 0352.
With winter tires, there may be decreased
dry road traction, increased road noise, and
shorter tread life. After changing to winter
tires, be alert for changes in vehicle
handling and braking.
If using winter tires:
.Use tires of the same brand and tread
type on all four wheel positions.
.Use only radial ply tires of the same size,
load range, and speed rating as the
original equipment tires.
Winter tires with the same speed rating as
the original equipment tires may not be
available for H, V, W, Y, and ZR speed rated
tires. If winter tires with a lower speed
rating are chosen, never exceed the tire's
maximum speed capability.
All-Terrain Tires
This vehicle may have all-terrain or
mud-terrain tires. These tires provide good
performance on most road surfaces, weather
conditions, and for off-road driving. See
Off-Road Driving 0208.
The tread pattern on these tires may wear
more unevenly than other tires. Consider
rotating the tires more frequently than at
12 000 km (7,500 mi) intervals if irregular
wear is noted when the tires are inspected.
See Tire Inspection 0348.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The example
shows a typical light truck tire sidewall.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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340 Vehicle Care
Light Truck (LT-Metric) Tire
(1) Light Truck (LT-Metric) Tire:The
United States version of a metric tire
sizing system. The letters LT as the first
two characters in the tire size mean a
light truck tire engineered to standards
set by the U.S. Tire and Rim
Association.
(2) Tire Width
:The 3-digit number
indicates the tire section width in
millimeters from sidewall to sidewall.
(3) Aspect Ratio
:A 2-digit number that
indicates the tire height-to-width
measurements. For example, if the tire
size aspect ratio is 75, as shown in
item (3) of the light truck (LT-Metric)
tire illustration, it would mean that the
tire's sidewall is 75 percent as high as it
is wide. (4) Construction Code
:A letter code is
used to indicate the type of ply
construction in the tire. The letter R
means radial ply construction; the
letter D means diagonal or bias ply
construction.
(5) Rim Diameter
:Diameter of the
wheel in inches.
(6) Load Range
:Load Range.
(7) Service Description
:The service
description indicates the load index and
speed rating of a tire. If two numbers
are given as in the example, 120/116,
then this represents the load index for
single versus dual wheel usage (single/
dual). The speed rating is the maximum
speed a tire is certified to carry a load.
Tire Terminology and Definitions
Air Pressure:The amount of air inside
the tire pressing outward on each
square inch of the tire. Air pressure is
expressed in kPa (kilopascal) or psi
(pounds per square inch).
Aspect Ratio
:The relationship of a
tire's height to its width. Belt
:A rubber coated layer of cords
that is located between the plies and
the tread. Cords may be made from
steel or other reinforcing materials.
Bead
:The tire bead contains steel
wires wrapped by steel cords that hold
the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which
the plies are laid at alternate angles
less than 90 degrees to the centerline
of the tread.
Cold Tire Pressure
:The amount of air
pressure in a tire, measured in kPa
(kilopascal) or psi (pounds per square
inch) before a tire has built up heat
from driving. See Tire Pressure0342.
DOT Markings
:A code molded into the
sidewall of a tire signifying that the tire
is in compliance with the U.S.
Department of Transportation (DOT)
Motor Vehicle Safety Standards. The
DOT code includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also identify the
tire manufacturer, production plant,
brand, and date of production.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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344 Vehicle Care
This sequence will continue upon
subsequent vehicle start-ups as long as the
malfunction exists.
When the malfunction indicator is
illuminated, the system may not be able to
detect or signal low tire pressure as
intended. TPMS malfunctions may occur for
a variety of reasons, including the
installation of replacement or alternate tires
or wheels on the vehicle that prevent the
TPMS from functioning properly. Always
check the TPMS malfunction telltale after
replacing one or more tires or wheels on
your vehicle to ensure that the replacement
or alternate tires and wheels allow the
TPMS to continue to function properly.
SeeTire Pressure Monitor Operation 0344.
See Radio Frequency Statement 0404.
Tire Pressure Monitor Operation
This vehicle may have a Tire Pressure
Monitor System (TPMS). The TPMS is
designed to warn the driver when a low tire
pressure condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire and
wheel assembly. The TPMS sensors monitor the air pressure in the tires and transmit the
tire pressure readings to a receiver located
in the vehicle.
When a low tire pressure condition is
detected, the TPMS illuminates the low tire
pressure warning light located on the
instrument cluster. If the warning light
comes on, stop as soon as possible and
inflate the tires to the recommended
pressure shown on the Tire and Loading
Information label. See
Vehicle Load Limits
0 215.
A message to check the pressure in a
specific tire displays in the Driver
Information Center (DIC). The low tire
pressure warning light and the DIC warning
message come on at each ignition cycle
until the tires are inflated to the correct
inflation pressure. If the vehicle has DIC
buttons, tire pressure levels can be viewed. For additional information and details about
the DIC operation and displays, see
Driver
Information Center (DIC) (Base Level) 0128
or
Driver Information Center (DIC) (Midlevel and
Uplevel) 0130.
The low tire pressure warning light may
come on in cool weather when the vehicle is
first started, and then turn off as the vehicle
is driven. This could be an early indicator
that the air pressure is getting low and
needs to be inflated to the proper pressure.
A Tire and Loading Information label shows
the size of the original equipment tires and
the correct inflation pressure for the tires
when they are cold. See Vehicle Load Limits
0 215, for an example of the Tire and
Loading Information label and its location.
Also see Tire Pressure 0342.
The TPMS can warn about a low tire
pressure condition but it does not replace
normal tire maintenance. See Tire Inspection
0 348, Tire Rotation 0349, and Tires0337.
Caution
Tire sealant materials are not all the
same. A non-approved tire sealant could
damage the TPMS sensors. TPMS sensor
(Continued)

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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348 Vehicle Care
The system is compatible with trailer tires
that have placard pressure values from
103 - 689 kpa (15 - 100 psi). The hole in the
wheel for the tire stem must be 11.43 mm
(0.453 in) or 15.88 mm (0.625 in) in
diameter. Use of the pressure sensors on a
wheel with a different stem hole size could
result in loss of air from the tire.
If a low trailer tire pressure condition is
detected, the TTPMS displays a warning
message on the DIC. If the warning message
is displayed, stop as soon as possible and
inflate the tires to the recommended
pressure shown on the tire placard on the
trailer.
In addition, the TTPMS monitors the
temperature of the trailer tires. If the
system detects a high temperature on one
or more of the trailer tires, a warning
message will be displayed on the DIC. If this
warning message is displayed, stop as soon
as possible, and inspect the overheated
trailer tire. Common causes for high trailer
tire temperature are underinflation,
overloading, or tire damage.TTPMS Malfunction Message
The TTPMS will not function properly if one
or more of the trailer tire sensors are
missing or inoperable. If the system detects
a malfunction, a DIC message indicates that
the system requires service. Some of the
conditions that can cause the service
message to occur are:
.One of the trailer tires has been replaced
with the spare tire which does not have a
learned TTPMS sensor. The DIC message
should turn off after the pressure sensor
is installed in the tire, and the learning
process is performed successfully. See
"TTPMS Sensor Learning Process" under
Trailering App0287.
.The TTPMS sensor learning process was
not done or not completed successfully.
The DIC message should go off after
successfully completing the sensor
learning process. See "TTPMS Sensor
Learning Process" under Trailering App
0 287.
.One or more TTPMS sensors are missing
or damaged. The DIC message should go
off when the TTPMS sensors are installed
and the sensor learning process is performed successfully. See "TTPMS
Sensor Learning Process" under
Trailering
App 0287.
.Operating electronic devices or being near
facilities using radio wave frequencies
similar to the TTPMS could cause
interference to the TTPMS which could
cause loss of signal reception from the
sensor.
.If the system does not receive the signal
from an individual sensor, an error
message may not occur until the vehicle
has been driver for a period of time.
If the TTPMS is not functioning properly, it
cannot detect or signal a low tire condition.
See your dealer for service if the DIC
message comes on and stays on when the
trailer tire pressures have been checked and
determined to be correct.
Tire Inspection
We recommend that the tires, including
the spare tire, if the vehicle has one, be
inspected for signs of wear or damage
at least once a month.