
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
248 Driving and Operating
Irregular Objects Affecting ACC
ACC may have difficulty detecting the
following objects:
.Vehicles in front of your vehicle that have
a rear aspect that is low, small,
or irregular
.An empty truck or trailer that has no
cargo in the cargo bed
.Vehicles with cargo extending from the
back end
.Non-standard shaped vehicles, such as
vehicle transport, vehicles with a side car
fitted, or horse carriages
.Vehicles that are low to the road surface
.Objects that are close to the front of your
vehicle
.Vehicles on which extremely heavy cargo
is loaded in the cargo area or rear seat
ACC Automatically Disengages
ACC may automatically disengage and the
driver will need to manually apply the
brakes to slow the vehicle if:
.The front camera is blocked or visibility is
reduced.
.The Traction Control System (TCS) or
StabiliTrak/ESC system has activated or
been disabled.
.There is a fault in the system.
.A DIC message displays to indicate that
ACC is temporarily unavailable.
The ACC indicator will turn white when ACC
is no longer active.
In some cases, when ACC is temporarily
unavailable, regular cruise control may be
used. See “Switching Between ACC and
Regular Cruise Control” previously in this
section. Always consider driving conditions
before using either cruise control system.
Notification to Resume ACC
ACC will maintain a follow gap behind a
detected vehicle and slow your vehicle to a
stop behind that vehicle. If the stopped vehicle ahead has driven
away and ACC has not resumed, the vehicle
ahead indicator will flash as a reminder to
check traffic ahead before proceeding. In
addition, the left and right sides of the
Safety Alert Seat (if equipped) will pulse
three times, or three beeps will sound. To
view available settings from the
infotainment screen, touch Settings >
Vehicle > Collision/Detection Systems > Alert
Type > Adaptive Cruise Go Notifier.
When the vehicle ahead drives away, ACC
resumes automatically if the stop was brief.
If necessary, press RES+ or the accelerator
pedal to resume ACC. If stopped for more
than two minutes or if the driver door is
opened and the driver seat belt is
unbuckled, the ACC automatically applies the
Electric Parking Brake (EPB) to hold the
vehicle. The EPB status light will turn on.
See
Electric Parking Brake 0234. To release
the EPB, press the accelerator pedal.
A DIC warning message may display
indicating to shift to P (Park) before exiting
the vehicle. See Vehicle Messages 0139.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
280 Driving and Operating
5. Gradually release the brake pedal toallow the chocks to absorb the load of
the trailer.
6. Reapply the brake pedal. Then, apply the parking brake and shift into P (Park).
7. Release the brake pedal.
Pulling the Trailer from the Water
To pull the trailer out of the water: 1. Press and hold the brake pedal.
2. Start the engine and shift into gear.
3. Release the parking brake.
4. Let up on the brake pedal.
5. Drive slowly until the tires are clear of the chocks.
6. Stop and have someone pick up and store the chocks.
7. Slowly pull the trailer from the water.
8. Once the vehicle and trailer have been driven from the sloped part of the boat
ramp, the vehicle can be shifted from
four-wheel-drive high. Shift into the drive
mode that is appropriate for the road
conditions.Caution
If the vehicle tires begin to spin and the
vehicle begins to slide toward the water,
remove your foot from the accelerator
pedal and apply the brake pedal. Seek
help to have the vehicle towed up
the ramp.
Maintenance when Trailer Towing
The vehicle needs service more often when
used to tow trailers. See Maintenance
Schedule 0394. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically to see that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily
overheat during severe operating conditions.
See Engine Overheating 0321.
Trailer Towing
If equipped with a diesel engine, see the
Duramax diesel supplement.
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
tow a trailer correctly, follow the
directions in this section and see your
dealer for important information about
towing a trailer with the vehicle.
Trailering is different than just driving the
vehicle by itself. Trailering means changes in
handling, acceleration, braking, and
durability. Successful, safe trailering takes
correct equipment, and it has to be used
properly.
The following information has many
time-tested, important trailering tips and
safety rules. Many of these are important
for your safety and that of your passengers.
Read this section carefully before pulling a
trailer.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
310 Vehicle Care
Towing the Vehicle
Transporting a Disabled Vehicle . . . . . . . 379
Recreational Vehicle Towing . . . . . . . . . . . 380
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 383
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 388
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
General Information
For service and parts needs, visit your
dealer. You will receive genuine GM parts
and GM-trained and supported service
people.
Genuine GM parts have one of these marks:
California Perchlorate Materials
Requirements
Certain types of automotive applications,
such as airbag initiators, seat belt
pretensioners, and lithium batteries
contained in electronic keys, may contain
perchlorate materials. Perchlorate Material–
special handling may apply. See
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and Modifications
Adding non-dealer accessories or making
modifications to the vehicle can affect
vehicle performance and safety, including
such things as airbags, braking, stability,
ride and handling, emissions systems,
aerodynamics, durability, Advanced Driver
Assistance Systems, and electronic systems
like antilock brakes, traction control, and
stability control. These accessories or
modifications could even cause malfunction
or damage not covered by the vehicle
warranty.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
348 Vehicle Care
(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 Pressure0350.
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. GVWR
:Gross Vehicle Weight Rating.
See Vehicle Load Limits 0210.
GAWR FRT
:Gross Axle Weight Rating
for the front axle. See Vehicle Load
Limits 0210.
GAWR RR
:Gross Axle Weight Rating
for the rear axle. See Vehicle Load
Limits 0210.
Intended Outboard Sidewall
:The side
of an asymmetrical tire, that must
always face outward when mounted on
a vehicle.
Kilopascal (kPa)
:The metric unit for air
pressure.
Light Truck (LT-Metric) Tire
:A tire used
on light duty trucks and some
multipurpose passenger vehicles.
Load Index
:An assigned number
ranging from 1 to 279 that corresponds
to the load carrying capacity of a tire.
Maximum Inflation Pressure
:The
maximum air pressure to which a cold
tire can be inflated. The maximum air
pressure is molded onto the sidewall.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Vehicle Care 391
Instrument Panel, Leather, Vinyl, Other
Plastic Surfaces, Low Gloss Paint
Surfaces, and Natural Open Pore Wood
Surfaces
Use a soft bristle brush to remove dust from
knobs and crevices on the instrument
cluster. Use a soft microfiber cloth
dampened with water to remove dust and
loose dirt. For a more thorough cleaning,
use a soft microfiber cloth dampened with a
mild soap and water solution.
Caution
Soaking or saturating leather, especially
perforated leather, as well as other
interior surfaces, may cause permanent
damage. Wipe excess moisture from
these surfaces after cleaning and allow
them to dry naturally. Never use heat,
steam, or spot removers. Do not use
liquids that contain alcohol or solvents on
leather seats. Do not use cleaners that
contain silicone or wax-based products.
Cleaners containing these solvents can
permanently change the appearance and
feel of leather or soft trim, and are not
recommended.Do not use cleaners that increase gloss,
especially on the instrument panel. Reflected
glare can decrease visibility through the
windshield under certain conditions.
Caution
Use of air fresheners may cause
permanent damage to plastics and
painted surfaces. If an air freshener
comes in contact with any plastic or
painted surface in the vehicle, blot
immediately and clean with a soft cloth
dampened with a mild soap solution.
Damage caused by air fresheners would
not be covered by the vehicle warranty.
Care of Seat Belts
Keep belts clean and dry.
{Warning
Do not bleach or dye seat belt webbing.
It may severely weaken the webbing. In
a crash, they might not be able to
provide adequate protection. Clean and
rinse seat belt webbing only with mild
soap and lukewarm water. Allow the
webbing to dry.
Floor Mats
{Warning
If a floor mat, a liner, or a liner insert is
the wrong size or is not properly
installed, it can interfere with the pedals.
Interference with the pedals can cause
unintended acceleration and/or increased
stopping distance, which can cause a
crash and injury. Make sure the floor
mat, liner, or liner insert does not
interfere with the pedals.
Use the following guidelines for proper floor
mat/liner use:
.The original equipment floor mats are
designed for your vehicle. If the floor
mats need to be replaced, it is
recommended that GM-certified floor
mats are purchased. Non-GM floor mats
may not fit properly and may interfere
with the pedals. Always check that the
floor mats do not interfere with the
pedals.
.Do not use a floor mat/liner if the vehicle
is not equipped with a floor mat retainer
on the driver side floor.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Service and Maintenance 397
Windshield and Wipers
.Visual inspection
Battery
.Battery visual inspection
.Battery test results
.Battery cables and connections
Systems, Fluids, and Visible Leak
Inspection
.Engine oil
.Transmission
.Drive axle
.Transfer case
.Engine cooling system
.Power steering, if equipped
.Fuel system
.Windshield washer fluid
Tire Inspection
.Tire pressure, tread depth, and wear
.Rotation, if applicable
.Alignment check, optional
.Reset tire pressure monitor
.Check tire sealant expiration date,
if equipped
.Check spare tire, if equipped
Brakes
.Check brake system
Visible and Functional Inspections
.Seat belt components
.Exhaust system
.Accelerator pedal
.Passenger compartment air filter,
if equipped
.Engine air filter
.Hoses
.Belts
.Shocks and struts
.Steering components
.Axle boots or driveshaft and u-joints
.Compartment lift struts, if equipped
.Floor mats secured, no interference with
pedals
.Horn
.Ignition lock, if equipped
.Starter switch
.Evaporative control system
Lubricate
.Chassis components
Special Application Services
.Vehicles with Dual Wheels: Check dual
wheel nut torque at 160, 1 600, and
10 000 km (100, 1,000, and 6,000 mi) of
driving. Repeat this service whenever a
tire/wheel is serviced or removed.
.Severe Commercial Use Vehicles Only:
Lubricate chassis components every oil
change.
.Have underbody flushing service
performed. See “Underbody Maintenance”
in Exterior Care 0383.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Technical Data 401
Technical Data
Vehicle Identification
Vehicle Identification Number (VIN) . . . 401
Service Parts Identification . . . . . . . . . . . . 401
Vehicle Data
Capacities and Specifications . . . . . . . . . . 402
Engine Drive Belt Routing . . . . . . . . . . . . . 404
Vehicle Identification
Vehicle Identification
Number (VIN)
This legal identifier is in the front corner of
the instrument panel, on the driver side of
the vehicle. It can be seen through the
windshield from outside. The Vehicle
Identification Number (VIN) also appears on
the Vehicle Certification label and certificates
of title and registration.
Engine Identification
The eighth character in the VIN is the
engine code. This code identifies the
vehicle's engine, specifications, and
replacement parts. See“Engine
Specifications” underCapacities and
Specifications 0402 for the vehicle's
engine code.
Service Parts Identification
There may be a large barcode on the
certification label on the center pillar that
you can scan for the following information:
.Vehicle Identification Number (VIN)
.Model designation
.Paint information
.Production options
If there is not a large barcode on this label,
then you will find this same information on
a label inside of the glove box.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
404 Technical Data
Engine Drive Belt Routing
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
6.6L Engine (Single Generator)
6.6L Engine (Dual Generator)