tow GMC SIERRA 2023 Owners Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
372 Vehicle Care
Caution
Use of a shield mounted in front of the
vehicle grille could restrict airflow and
cause damage to the transmission. The
repairs would not be covered by the
vehicle warranty. If using a shield, only
use one that attaches to the towing
vehicle.
Dinghy Towing (Two-Wheel-Drive
Vehicles and Vehicles with a
Single-Speed Transfer Case)
Caution
If a vehicle with two-wheel drive or a
single-speed transfer case is towed with
all four wheels on the ground, the
drivetrain components could be damaged.
The repairs would not be covered by the
vehicle warranty.
Two-wheel-drive vehicles and vehicles with a
single-speed transfer case should not be
towed with all four wheels on the ground.
Dinghy Towing (Vehicles with a
Two-Speed Transfer Case)
Only dinghy tow four-wheel-drive vehicles
with a two-speed transfer case that have an
N (Neutral) and a 4
n(Four-Wheel Drive
Low) setting.
{Warning
Shifting a four-wheel-drive vehicle's
transfer case into N (Neutral) can allow
the vehicle to move even if the
transmission is in P (Park). You or others
could be injured. Set the parking brake
and use wheel blocks before shifting the
transfer case to N (Neutral).
To dinghy tow: 1. Position the vehicle being towed behind the tow vehicle, facing forward and on a
level surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Apply the parking brake and start the engine.
4. Shift the transfer case to N (Neutral). See “Shifting into N (Neutral)” under
Four-Wheel Drive 0234.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 373
5. With the engine running, release theparking brake and verify that the
transfer case is in N (Neutral) by shifting
the transmission to D (Drive) and then to
R (Reverse). There should be no
movement while shifting the
transmission.
6. Shift the transmission to D (Drive).
7. If equipped with an ignition key, turn the ignition to ACC/ACCESSORY.
If equipped with Keyless Access, turn the
engine off. Disregard the Shift to P (Park)
DIC message. See Ignition Positions (Key
Access) 0221 or
Ignition Positions (Keyless Access) 0223.
{Warning
To avoid death, serious injury,
or property damage, before dinghy
towing the vehicle, always disconnect and
secure the negative battery cable and
cover the negative battery post and cable
with a non-conductive material. If the
battery is left connected or the battery
cable contacts the post, the Electric
Parking Brake may activate during
towing, which could cause a crash. 8. Disconnect the negative (–) battery
cable. See “Negative Battery Cable
Disconnection” inBattery - North
America 0319.
9. Shift the transmission to P (Park).
Caution
If the steering column is locked, vehicle
damage may occur.
10. Move the steering wheel to make sure the steering column is unlocked.
11. If the vehicle has an ignition key, keep it in the towed vehicle in ACC/ACCESSORY
to prevent the steering column from
locking. If the vehicle is equipped with
Keyless Access, keep the RKE transmitter
outside of the vehicle and manually lock
the doors. Access the vehicle by using
the key in the door lock. See Door Locks
0 23.
Disconnecting the Towed Vehicle
Before disconnecting from the tow vehicle: 1. Park on a level surface. Secure the vehicle with wheel blocks.
2. Re-connect the negative (–) battery. See Battery - North America 0319. 3. Turn on the ignition with the engine off.
For vehicles with a key, turn the ignition
to ON/RUN with the engine off. If the
vehicle is equipped with Keyless Access,
with your foot off the brake pedal, press
and hold ENGINE START/STOP for
five seconds until the green light comes
on in the button. See Ignition Positions
(Key Access) 0221 or
Ignition Positions (Keyless Access) 0223.
4. Set the parking brake. See Electric
Parking Brake 0239.
5. Disconnect from the tow vehicle.
6. Shift the transmission to N (Neutral).
7. Shift the transfer case to 2
m(Two-Wheel
Drive High). When the shift to 2
m
(Two-Wheel Drive High) is complete, the
light in the instrument cluster will stop
flashing and stay lit. See
Four-Wheel-Drive Light 0123.
8. Start the engine. Check that the vehicle is in 2
m(Two-Wheel Drive High) by
starting the engine and shifting the
transmission to D (Drive) and then to
R (Reverse). There should be movement
of the vehicle while shifting.
9. Shift the transmission to P (Park) and turn off the ignition.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
374 Vehicle Care
10. Release the parking brake and removethe wheel blocks.
11. Reset any lost presets. The outside temperature display will
default to 0 °C (32 °F) but will reset with
normal usage.
Dolly Towing
Caution
Do not tow this vehicle with two wheels
on the ground, or vehicle damage could
occur. This damage would not be covered
by the vehicle warranty.
Dolly towing this vehicle is not allowed with
either the front or the rear tires on the
ground for two-wheel drive or four-wheel
drive, regardless of transfer case.
Appearance Care
Exterior Care
Locks
Locks are lubricated at the factory. Use a
de-icing agent only when absolutely
necessary, and have the locks greased after
using. See Recommended Fluids and
Lubricants 0389.
Washing the Vehicle
To preserve the vehicle's finish, wash it
often and out of direct sunlight.
{Warning
Do not power wash any part of the
vehicle’s interior, including the vinyl floor
covering. This could damage safety and
other systems in the vehicle, which
would not be covered by the vehicle
warranty.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
376 Vehicle Care
Dry the finish with a soft, clean chamois or
an all-cotton towel to avoid surface
scratches and water spotting.
Finish Care
Application of aftermarket clearcoat sealant/
wax materials is not recommended.
If painted surfaces are damaged, see your
dealer to have the damage assessed and
repaired. Foreign materials such as calcium
chloride and other salts, ice melting agents,
road oil and tar, tree sap, bird droppings,
chemicals from industrial chimneys, etc., can
damage the vehicle's finish if they remain
on painted surfaces. Wash the vehicle as
soon as possible. If necessary, use
non-abrasive cleaners that are marked safe
for painted surfaces to remove foreign
matter.
Occasional hand waxing or mild polishing
should be done to remove residue from the
paint finish. See your dealer for approved
cleaning products.
Do not apply waxes or polishes to uncoated
plastic, vinyl, rubber, decals, simulated
wood, or flat paint as damage can occur.
Caution
Machine compounding or aggressive
polishing on a basecoat/clearcoat paint
finish may damage it. Use only
non-abrasive waxes and polishes that are
made for a basecoat/clearcoat paint finish
on the vehicle.
To keep the paint finish looking new, keep
the vehicle garaged or covered whenever
possible.
Protecting Exterior Bright Metal Moldings
Caution
Failure to clean and protect the bright
metal moldings can result in a hazy
white finish or pitting. This damage
would not be covered by the vehicle
warranty.
The bright metal moldings on the vehicle
are aluminum, chrome or stainless steel. To
prevent damage always follow these
cleaning instructions:
.Be sure the molding is cool to the touch
before applying any cleaning solution.
.Use only approved cleaning solutions for
aluminum, chrome or stainless steel.
Some cleaners are highly acidic or contain
alkaline substances and can damage the
moldings.
.Always dilute a concentrated cleaner
according to the manufacturer’s
instructions.
.Do not use cleaners that are not intended
for automotive use.
.Use a nonabrasive wax on the vehicle
after washing to protect and extend the
molding finish.
Spray-In Bedliner Care
Caution
Using silicone-based products may
damage the bedliner, reduce the
slip-resistant texture, and attract dirt.
A spray-in bedliner is a permanent coating
that bonds to the truck bed and cannot be
removed. Promptly rinse the bedliner surface
following a chemical spill to avoid
permanent damage.
Spray-in bedliners can fade from oxidation,
road dirt, heavy-duty hauling, and hard
water stains. Clean it periodically by
washing off the loose dirt and using a mild

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
378 Vehicle Care
Clean rubber blades using a lint-free cloth or
paper towel soaked with windshield washer
fluid or a mild detergent. Wash the
windshield thoroughly when cleaning the
blades. Bugs, road grime, sap, and a buildup
of vehicle wash/wax treatments may cause
wiper streaking.
Replace the wiper blades if they are worn or
damaged. Damage can be caused by
extreme dusty conditions, sand, salt, heat,
sun, snow, and ice.
Weatherstrips
Apply weatherstrip lubricant on
weatherstrips to make them last longer, seal
better, and not stick or squeak. Lubricate
weatherstrips once a year. Hot, dry climates
may require more frequent application. Black
marks from rubber material on painted
surfaces can be removed by rubbing with a
clean cloth. SeeRecommended Fluids and
Lubricants 0389.
Tires
Use a stiff brush with tire cleaner to clean
the tires.
Caution
Using petroleum-based tire dressing
products on the vehicle may damage the
paint finish and/or tires. When applying a
tire dressing, always wipe off any
overspray from all painted surfaces on
the vehicle.
Wheels and Wheel Trim
Use a soft, clean cloth with mild soap and
water to clean the wheels. After rinsing
thoroughly with clean water, dry with a
soft, clean towel. A wax may then be
applied.
Caution
Chrome wheels and chrome wheel trim
may be damaged if the vehicle is not
washed after driving on roads that have
been sprayed with magnesium chloride or
calcium chloride. These are used on roads
for conditions such as dust and ice.
Always wash the chrome with soap and
water after exposure.
Caution
To avoid surface damage on wheels and
wheel trim, do not use strong soaps,
chemicals, abrasive polishes, cleaners,
or brushes. Use only GM approved
cleaners. Do not drive the vehicle through
an automatic car wash that uses silicon
carbide tire/wheel cleaning brushes.
Damage could occur and the repairs
would not be covered by the vehicle
warranty.
Brake System
Visually inspect brake lines and hoses for
proper hook-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear
and rotors for surface condition. Inspect
drum brake linings/shoes for wear or cracks.
Inspect all other brake parts.
Steering, Suspension, and Chassis
Components
Visually inspect steering, suspension, and
chassis components for damaged, loose,
or missing parts or signs of wear at least
once a year.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 381
Vinyl/Rubber
If equipped with vinyl floor and rubber floor
mats, use a soft cloth and/or brush
dampened with water to remove dust and
loose dirt. For more thorough cleaning, use
a mild soap and water solution.
{Warning
Do not use cleaners that contain silicone,
wax-based products, or cleaners that
increase gloss on vinyl/rubber floor and
mats. These cleaners can permanently
change the appearance and feel of the
vinyl/rubber and can make the floor
slippery. Your foot could slip while
operating the vehicle, and you could lose
control, resulting in a crash. You or
others could be injured.
Fabric/Carpet/Suede
Start by vacuuming the surface using a soft
brush attachment. If a rotating vacuum
brush attachment is being used, only use it
on the floor carpet. Before cleaning, gently
remove as much of the soil as possible:
.Gently blot liquids with a paper towel.
Continue blotting until no more soil can
be removed.
.For solid soils, remove as much as
possible prior to vacuuming.
To clean: 1. Saturate a clean, lint-free colorfast cloth with water. Microfiber cloth is
recommended to prevent lint transfer to
the fabric or carpet.
2. Remove excess moisture by gently wringing until water does not drip from
the cleaning cloth.
3. Start on the outside edge of the soil and gently rub toward the center. Fold the
cleaning cloth to a clean area frequently
to prevent forcing the soil into the
fabric.
4. Continue gently rubbing the soiled area until there is no longer any color
transfer from the soil to the cleaning
cloth.
5. If the soil is not completely removed, use a mild soap solution followed only
by plain water.
If the soil is not completely removed, it may
be necessary to use a commercial upholstery
cleaner or spot lifter. Test a small hidden
area for colorfastness before using a commercial upholstery cleaner or spot lifter.
If ring formation occurs, clean the entire
fabric or carpet.
After cleaning, use a paper towel to blot
excess moisture.
Cleaning High Gloss Surfaces and Vehicle
Information and Radio Displays
Use a microfiber cloth on high gloss surfaces
or vehicle displays. First, use a soft bristle
brush to remove dirt that can scratch the
surface. Then gently clean by rubbing with a
microfiber cloth. Never use window cleaners
or solvents. Periodically hand wash the
microfiber cloth separately, using mild soap.
Do not use bleach or fabric softener. Rinse
thoroughly and air dry before next use.
Caution
Do not attach a device with a suction cup
to the display. This may cause damage
and would not be covered by the vehicle
warranty.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Service and Maintenance 385
Because of the way people use vehicles,
maintenance needs vary. There may need to
be more frequent checks and services. The
Additional Required Services - Normal are for
vehicles that:
.Carry passengers and cargo within
recommended limits on the Tire and
Loading Information label. SeeVehicle
Load Limits 0215.
.Are driven on reasonable road surfaces
within legal driving limits.
.Use the recommended fuel. See
Recommended Fuel 0263.
Refer to the information in the Maintenance
Schedule Additional Required Services -
Normal Service.
The Additional Required Services - Severe are
for vehicles that are:
.Mainly driven in heavy city traffic in hot
weather.
.Mainly driven in hilly or mountainous
terrain.
.Frequently towing a trailer.
.Used for high speed or competitive
driving.
.Used for taxi, police, or delivery service. Refer to the information in the Maintenance
Schedule Additional Required Services -
Severe Service.
{Warning
Performing maintenance work can be
dangerous and can cause serious injury.
Perform maintenance work only if the
required information, proper tools, and
equipment are available. If they are not,
see your dealer to have a trained
technician do the work. See
Doing Your
Own Service Work 0303.
Maintenance Schedule
Tire Rotation and Required Services
Every 12 000 km (7,500 mi)
Tires are rotated to achieve a more uniform
wear for all tires. The first rotation is the
most important.
Anytime unusual wear is noticed, rotate the
tires as soon as possible, check for proper
tire inflation pressure, and check for
damaged tires or wheels. If the unusual
wear continues after the rotation, check the wheel alignment. See
When It Is Time for
New Tires 0351 and
Wheel Replacement 0354.
.Perform Multi-Point Vehicle Inspection.
See Multi-Point Vehicle Inspection (MPVI)
0 387.
.Lubricate body components. See Exterior
Care 0374.
Power Take Off (PTO) and Extended
Idle Use
When the vehicle is used with the PTO
equipment or used in a way that requires
extended idle time, one hour of use shall be
deemed the same as 53 km (33 mi). See
Driver Information Center (DIC) (Base Level)
0128 or
Driver Information Center (DIC) (Midlevel and
Uplevel) 0130 for hourmeter, if equipped.
Additional Required Services —Normal
Service
Every 12 000 km (7,500 mi)
.Check engine oil level and oil
life percentage. If needed, change engine
oil and filter, and reset oil life system. Or
when the CHANGE ENGINE OIL SOON
message displays, have the engine oil
and filter changed within the next

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
386 Service and Maintenance
1 000 km/600 mi. If driven under the best
conditions, the engine oil life system may
not indicate the need for vehicle service
for up to a year. The engine oil and filter
must be changed at least once a year and
the oil life system must be reset. Your
trained dealer technician can perform this
work. If the engine oil life system is reset
accidentally, service the vehicle within
5 000 km/3,000 mi since the last service.
Reset the oil life system when the oil is
changed. SeeEngine Oil Life System
0 308.
.When the REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the next engine oil
change. When the REPLACE ENGINE AIR
FILTER SOON message displays, the
engine air filter should be replaced at the
earliest convenience. Reset the engine air
filter life system after the engine air filter
is replaced. See Engine Air Filter Life
System 0309.
Every 36 000 km (22,500 mi)
.Replace passenger compartment air filter.
Or every 24 months, whichever comes
first. More frequent passenger
compartment air filter replacement may
be needed if driving in areas with heavy traffic, poor air quality, high dust levels,
or environmental allergens. Passenger
compartment air filter replacement may
also be needed if there is reduced airflow,
window fogging, or odors. Your GM
dealer can help determine when to
replace the filter.
Every 80 500 km (50,000 mi)
.Change transfer case fluid, if equipped
with 4WD. Do not directly power wash
the transfer case and/or front/rear axle
output seals. High pressure water can
overcome the seals and contaminate the
transfer case fluid. Contaminated fluid will
decrease the life of the transfer case and/
or axles and should be replaced.
Every 156 000 km (97,500 mi)
.Replace spark plugs. Inspect spark plug
wires and/or boots.
Every 161 000 km (100,000 mi)
.Replace hood and/or body lift support gas
struts. Or every 10 years, whichever
comes first. See Gas Strut(s)0324.
Every 240 000 km (150,000 mi)
.Drain and fill engine cooling system. Or
every six years, whichever comes first.
See Cooling System 0311.
Severe Conditions Requiring More
Frequent Maintenance*
.Public service, military, or commercial use
vehicles to include the following:
‐ Ambulances, police cars, and
emergency rescue vehicles.
‐ Civilian vehicles such as light duty
pick-up trucks, SUVs, and passenger
cars that are used in military
applications.
‐ Recovery vehicles such as tow trucks
and flatbed single vehicle carriers or
any vehicle that is consistently used in
towing trailers or other loads.
‐ High use commercial vehicles such as
courier delivery vehicles, private
security patrol vehicles, or any vehicles
that operate on a 24–hour basis.
‐ Any vehicle consistently operated in a
high sand or dust environment such as
those used on oil pipelines and similar
applications.
.Vehicles that are regularly used for short
trips of 6 km (4 mi) or less.
The oil life indicator will show you when
to change the oil and filter. Under severe
conditions the indicator may come on
before 12 000 km (7,500 mi).

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
400 Customer Information
Coverage
Services are provided for the duration of the
vehicle's powertrain warranty.
In the U.S., anyone driving the vehicle is
covered. In Canada, a person driving the
vehicle without permission from the owner
is not covered.
Roadside Assistance is not a part of the New
Vehicle Limited Warranty. General Motors
North America and GMC reserve the right to
make any changes or discontinue the
Roadside Assistance program at any time
without notification.
General Motors North America and GMC
reserve the right to limit services or
payment to an owner or driver if they
decide the claims are made too often, or the
same type of claim is made many times.
Services Provided
.Emergency Fuel Delivery:Delivery of
enough fuel for the vehicle to get to the
nearest service station.
.Lock-Out Service: Service to unlock the
vehicle if you are locked out. A remote
unlock may be available if you have OnStar. For security reasons, the driver
must present identification before this
service is given.
.Emergency Tow from a Public Road or
Highway:
Tow to the nearest GMC dealer
for warranty service, or if the vehicle was
in a crash and cannot be driven.
Assistance is not given when the vehicle
is stuck in the sand, mud, or snow.
.Flat Tire Change: Service to change a flat
tire with the spare tire. The spare tire,
if equipped, must be in good condition
and properly inflated. It is the owner's
responsibility for the repair or
replacement of the tire if it is not covered
by the warranty.
.Battery Jump Start: Service to jump start
a dead battery.
.Trip Interruption Benefits and Assistance:
If your trip is interrupted due to a
warranty event, incidental expenses may
be reimbursed within the Powertrain
warranty period. Items considered are
reasonable and customary hotel, meals,
rental car, or a vehicle being delivered
back to the customer, up to 500 miles.
Services Not Included in Roadside
Assistance
.Impound towing caused by violation of
any laws
.Legal fines
.Mounting, dismounting, or changing of
snow tires, chains, or other traction
devices
Service is not provided if a vehicle is in an
area that is not accessible to the service
vehicle or is not a regularly traveled or
maintained public road, which includes ice
and winter roads. Off-road use is not
covered.
Services Specific to Canadian-Purchased
Vehicles
.Fuel Delivery: Reimbursement is up to 7 L.
Diesel fuel delivery may be restricted.
Propane and other fuels are not provided
through this service.
.Lock-Out Service: Vehicle registration is
required.
.Trip Interruption Benefits and Assistance:
Must be over 150 km from where your
trip was started to qualify.
Pre-authorization, original detailed
receipts, and a copy of the repair orders
are required. Once authorization has been

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Customer Information 403
GM vehicle by limiting compensation for
damage repairs through the use of
aftermarket collision parts. Some insurance
companies will not specify aftermarket
collision parts. When purchasing insurance,
we recommend that you ensure that the
vehicle will be repaired with GM original
equipment collision parts. If such insurance
coverage is not available from your current
insurance carrier, consider switching to
another insurance carrier.
If the vehicle is leased, the leasing company
may require you to have insurance that
ensures repairs with Genuine GM Original
Equipment Manufacturer (OEM) parts or
Genuine Manufacturer replacement parts.
Read the lease carefully, as you may be
charged at the end of the lease for poor
quality repairs.
If a Crash Occurs
If there has been an injury, call emergency
services for help. Do not leave the scene of
a crash until all matters have been taken
care of. Move the vehicle only if its position
puts you in danger, or you are instructed to
move it by a police officer.Give only the necessary information to
police and other parties involved in the
crash.
For emergency towing see
Roadside
Assistance Program 0399.
Gather the following information:
.Driver name, address, and telephone
number
.Driver license number
.Owner name, address, and telephone
number
.Vehicle license plate number
.Vehicle make, model, and model year
.Vehicle Identification Number (VIN)
.Insurance company and policy number
.General description of the damage to the
other vehicle
Choose a reputable repair facility that uses
quality replacement parts. See “Collision
Parts” earlier in this section.
If the airbag has inflated, see What Will You
See after an Airbag Inflates? 069.
Managing the Vehicle Damage Repair
Process
In the event that the vehicle requires
damage repairs, GM recommends that you
take an active role in its repair. If you have
a pre-determined repair facility of choice,
take the vehicle there, or have it towed
there. Specify to the facility that any
required replacement collision parts be
original equipment parts, either new
Genuine GM parts or recycled original GM
parts. Remember, recycled parts will not be
covered by the GM vehicle warranty.
Insurance pays the bill for the repair, but
you must live with the repair. Depending on
your policy limits, your insurance company
may initially value the repair using
aftermarket parts. Discuss this with the
repair professional, and insist on Genuine
GM parts. Remember, if the vehicle is
leased, you may be obligated to have the
vehicle repaired with Genuine GM parts,
even if your insurance coverage does not
pay the full cost.
If another party's insurance company is
paying for the repairs, you are not obligated
to accept a repair valuation based on that
insurance company's collision policy repair
limits, as you have no contractual limits