2021 CHEVROLET SILVERADO 2500HD Owner's Manual

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
296 Driving and Operating
Settings View
Within the Trailering App, touch the Settings
tab to modify the following settings:
.Trailer Detection Alert
.Maintenance Alerts
.Theft Alert
.Tow/Haul Mode Reminder
.Trailer Length Indicator
Trailer Detection Alert
The Trailer Detection Alert setting will be on
by default. Turn it off to disable the Trailer
Detection pop-up from displaying when a
trailer is connected. The Guest Trailer Profile
will become the active Trailer Profile, unless
another Trailer Profile is selected manually
through the Trailering App. If this setting is
disabled while a Custom Trailer Profile is
active, that Trailer Profile will remain the
active profile until the trailer is
disconnected.
Maintenance Alerts
Touch Maintenance Alerts to view the
Maintenance Alerts settings page. These
alerts are based on the Trailer Profile, so the
settings for each Trailer Profile must beturned on or off. Touch a profile to view
more information or adjust the setting for
that profile.
The setting will be on by default for each
profile. All Maintenance Alerts for that active
Trailer Profile will be received.
Turn a setting off to not receive any of the
Maintenance Alerts when that Trailer Profile
is active.
Theft Alert
A theft alert can be set if a trailer is
connected and the alert is enabled. When
the trailer is disconnected and the vehicle is
off, an alarm will sound.
Touch Theft Alert in Settings to view the
Theft Alert settings page. These alerts are
based on the Trailer Profile, so the settings
for each Trailer Profile must be turned on or
off. Touch a profile to view more
information or adjust the setting for that
profile.
This setting will be off by default for each
Trailer Profile, including the Guest Trailer
Profile.
A smartphone will receive a notification that
the trailer related to the selected Trailer
Profile is disconnected from the vehicle,if the setting is on for the active Trailer
Profile, the vehicle has an OnStar or
connected service plan and the smartphone
number has been added to the account for
this notification.
If the setting is turned off for a given Trailer
Profile, the smartphone will not receive this
security notification even if the Trailer
Profile is active.
Tow/Haul Mode Reminder
This is a reminder to turn on the Tow/Haul
Mode when towing a trailer. See
Tow/Haul
Mode 0235.
Touch Tow/Haul Mode Reminder in Settings
to view the Tow/Haul Mode Reminder
settings page. These alerts are based on the
Trailer Profile, so the settings for each
Trailer Profile must be turned on or off.
Touch a profile to view more information or
to adjust the setting for that profile.
This setting will default to OFF for each
Trailer Profile, including the Guest Trailer
Profile.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Driving and Operating 297
If Tow/Haul Mode is off and this setting is
on for a Trailer Profile, each time the
ignition is turned on a reminder will appear
to turn on Tow/Haul Mode when the Trailer
Profile is active.
If Tow/Haul Mode is on and this setting is
on for a Trailer Profile, the reminder will not
appear when the Trailer Profile is active.
Trailer Length Indicator
Touch Trailer Length Indicator to view the
Trailer Length Indicator settings page. If this
setting is ON a guideline is displayed in the
side mirror camera view to indicate the rear
of the attached trailer. If this setting is OFF
the guideline will not be displayed.
This setting will default to OFF if the trailer
length indicator feature is not set up. See
"Towing Assistance" for details on the setup.
Conversions and Add-Ons
Add-On Electrical Equipment
{Warning
The Data Link Connector (DLC) is used for
vehicle service and Emission Inspection/
Maintenance testing. SeeMalfunction
Indicator Lamp (Check Engine Light) 0111.
A device connected to the DLC —such as
an aftermarket fleet or driver-behavior
tracking device —may interfere with
vehicle systems. This could affect vehicle
operation and cause a crash. Such devices
may also access information stored in the
vehicle’s systems.
Caution
Some electrical equipment can damage
the vehicle or cause components to not
work and would not be covered by the
vehicle warranty. Always check with your
dealer before adding electrical equipment.
Add-on equipment can drain the vehicle's
12-volt battery, even if the vehicle is not
operating. The vehicle has an airbag system. Before
attempting to add anything electrical to the
vehicle, see
Servicing the Airbag-Equipped
Vehicle 066 and
Adding Equipment to the Airbag-Equipped
Vehicle 066.
For information on wiring auxiliary switches,
see www.gmupfitter.com or contact your
dealer.
Adding a Snow Plow or Similar
Equipment
Caution
Do not exceed 72 km/h (45 mph) with a
snow plow mounted to the vehicle. The
vehicle could overheat and be damaged.
Before installing a snow plow on the vehicle,
follow these guidelines:
Caution
If the vehicle does not have the snow
plow prep package, RPO VYU, adding a
plow can damage the vehicle, and the
repairs would not be covered by the
vehicle warranty. Unless the vehicle was
built to carry a snow plow, do not add
(Continued)

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
298 Driving and Operating
Caution (Continued)
one to the vehicle. If the vehicle has RPO
VYU, then the payload the vehicle can
carry will be reduced when a snow plow
is installed. The vehicle can be damaged
if either the front or rear axle ratings or
the Gross Vehicle Weight Rating (GVWR)
are exceeded.
The plow the vehicle can carry depends on
many things, such as:
.The options the vehicle came with, and
the weight of those options.
.The weight and number of passengers to
be carried.
.The weight of items added to the vehicle,
like a tool box or truck cap.
.The total weight of any additional cargo
to be carried.
To safely carry a snow plow on the vehicle:
.With a snow plow attached, the engine
coolant temperature gauge may show a
higher temperature than while driving
without one. The snow plow could block
the airflow to the radiator. This could be
more noticeable as vehicle speed
increases. At speeds above 72 km/h
(45 mph), this may cause the engine coolant to overheat. Move or angle the
snow plow blade to allow increased
airflow to the radiator.
.To increase the airflow, move the snow
plow blade position.
.If driving more than 24 km/h (15 mi),
angle the plow blade position.
.Make sure the weight on the front and
rear axles does not exceed the axle rating
for each.
.Follow the snowplow manufacturer’s
recommendations for any rear ballast that
may be required. Rear ballast may be
required to ensure a proper front and rear
weight distribution ratio even though the
actual weight at the front axle may be
less than the front axel rating.
.The snowplow manufacturer or installer
can assist in determining the amount of
rear ballast required to ensure that the
vehicle with the attached snowplow does
not exceed the GVW rating, the front and
rear axle ratings, or the front and rear
weight distribution ratio.
Front axle reserve capacity is the difference
between the Front Gross Axle Weight
Rating (GAWR) and the front axle weight of
the vehicle with full fuel, passengers, and any other cargo. This is the amount of
weight that can be added to the front axle
before reaching the Front GAWR.
To calculate the amount of weight any front
accessory, such as a snow plow, is adding to
the front axle, use this formula:
(W x (A + W.B.)) /W.B.= Weight the accessory
is adding to the front axle.
Where:
IW = Weight of added accessory
IA = Distance that the accessory is in
front of the front axle
IW.B. = Vehicle Wheelbase

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Driving and Operating 299
For example, adding a 318 kg (700 lb) snow
plow actually adds more than 318 kg (700 lb)
to the front axle. Using the formula, if the
snow plow is 122 cm (4 ft) in front of the
front axle and the wheelbase is 305 cm
(10 ft), then:IW = 318 kg (700 lb)
IA = 122 cm (4 ft)
IW.B. = 305 cm (10 ft)
(W x (A + W.B.)/W.B. = (318 x (122 + 305))/305
= 445 kg (980 lb)
This means if the front axle reserve capacity
is more than 445 kg (980 lb), the snow plow
could be added without exceeding the
front GAWR.
Heavier equipment can be added on the
front of the vehicle if less cargo or fewer
passengers are carried, or by positioning
cargo toward the rear. This reduces the load
on the front. However, the front GAWR, rear
GAWR, and Gross Vehicle Weight
Rating (GVWR) must never be exceeded.{Warning
On some vehicles that have certain front
mounted equipment, such as a snow
plow, it may be possible to load the front
axle to the front Gross Axle Weight
Rating (GAWR) but not have enough
weight on the rear axle to have proper
braking performance. If the brakes cannot
work properly, the vehice could crash.
Always follow the snow plow
manufacturer or installer's
recommendation for rear ballast to
ensure a proper front and rear weight
distribution ratio. Maintaining a proper
front and rear weight distribution ratio is
necessary to provide proper braking
performance.
See your dealer for additional advice and
information about using a snow plow on the
vehicle. Also, see Vehicle Load Limits 0217.
Pickup Conversion to Chassis Cab
We are aware that some vehicle owners
might consider having the pickup box
removed and a commercial or recreational
body installed. Owners should be aware
that, as manufactured, there are differences
between a chassis cab and a pickup with the
box removed which could affect vehicle
safety. The components necessary to adapt
a pickup to permit its safe use with a
specialized body should be installed by the
body builder.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
300 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 301
California Proposition 65 Warning . . . . . 301
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 301
Accessories and Modifications . . . . . . . . . 302
Vehicle Checks
Doing Your Own Service Work . . . . . . . . 302
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Engine Compartment Overview . . . . . . . 304
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
Engine Oil Life System . . . . . . . . . . . . . . . . 307
Automatic Transmission Fluid . . . . . . . . . 308
Engine Air Filter Life System . . . . . . . . . . 308
Engine Air Cleaner/Filter . . . . . . . . . . . . . . 309
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 310
Engine Overheating . . . . . . . . . . . . . . . . . . . . 312
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . 314
Engine Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Power Steering Fluid . . . . . . . . . . . . . . . . . . . 314
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Brake Pad Life System . . . . . . . . . . . . . . . . . 316
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Battery - North America . . . . . . . . . . . . . . . 318
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 320 Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Noise Control System . . . . . . . . . . . . . . . . . 320
Starter Switch Check . . . . . . . . . . . . . . . . . . . 321
Automatic Transmission Shift Lock
Control Function Check . . . . . . . . . . . . . . 322
Ignition Transmission Lock Check . . . . . . 322
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Wiper Blade Replacement . . . . . . . . . . . . . 322
Glass Replacement . . . . . . . . . . . . . . . . . . . . . 323
Windshield Replacement . . . . . . . . . . . . . . . 323
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 324
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 324
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 . . . . . . . . . . . . . . . . . . . . 328
Electrical System
Electrical System Overload . . . . . . . . . . . . 328 Fuses and Circuit Breakers . . . . . . . . . . . . . 329
Engine Compartment Fuse Block . . . . . . 329
Instrument Panel Fuse Block (Left) . . . . . 332
Instrument Panel Fuse Block (Right) . . . 334
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 337
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . . 337
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 338
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 339
Tire Terminology and Definitions . . . . . . 339
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
Tire Pressure Monitor System . . . . . . . . . 342
Tire Pressure Monitor Operation . . . . . . 343
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 348
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 348
When It Is Time for New Tires . . . . . . . . 350
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . 351
Different Size Tires and Wheels . . . . . . . . 352
Uniform Tire Quality Grading . . . . . . . . . . 352
Wheel Alignment and Tire Balance . . . . 354
Wheel Replacement . . . . . . . . . . . . . . . . . . . 354
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 355
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 356
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . 366
Jump Starting
Jump Starting - North America . . . . . . . . 367

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Vehicle Care 301
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . 369
Recreational Vehicle Towing . . . . . . . . . . . 370
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
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 Proposition 65 Warning
{Warning
Most motor vehicles, including this one,
as well as many of its service parts and
fluids, contain and/or emit chemicals
known to the State of California to cause(Continued)
Warning (Continued)
cancer and birth defects or other
reproductive harm. Engine exhaust, many
parts and systems, many fluids, and
some component wear by-products
contain and/or emit these chemicals. For
more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
See Battery - North America 0318 and
Jump Starting - North America 0367 and
the back cover.
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.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
302 Vehicle Care
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, 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.
Damage to suspension components caused
by modifying vehicle height outside of
factory settings will not be covered by the
vehicle warranty.
Damage to vehicle components resulting
from modifications or the installation or use
of non-GM certified parts, including control
module or software modifications, is not
covered under the terms of the vehicle
warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to complement
and function with other systems on the
vehicle. See your dealer to accessorize the
vehicle using genuine GM Accessories
installed by a dealer technician.Also, see
Adding Equipment to the
Airbag-Equipped Vehicle 066.
Vehicle Checks
Doing Your Own Service Work
{Warning
It can be dangerous to work on your
vehicle if you do not have the proper
knowledge, service manual, tools,
or parts. Always follow owner’s manual
procedures and consult the service
manual for your vehicle before doing any
service work.
If doing some of your own service work, use
the proper service manual. It tells you much
more about how to service the vehicle than
this manual can. To order the proper service
manual, see Publication Ordering
Information 0408.
This vehicle has an airbag system. Before
attempting to do your own service work,
see Servicing the Airbag-Equipped Vehicle
0 66. If equipped with remote vehicle start, open
the hood before performing any service
work to prevent remote starting the vehicle
accidentally. See
Remote Vehicle Start 020.
Keep a record with all parts receipts and list
the mileage and the date of any service
work performed. See Maintenance Records
0 396.Caution
Even small amounts of contamination can
cause damage to vehicle systems. Do not
allow contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
Turn the vehicle off before opening the
hood. If the engine is running with the
hood open, you or others could be
injured.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Vehicle Care 303
{Warning
Components under the hood can get hot
from running the engine. To help avoid
the risk of burning unprotected skin,
never touch these components until they
have cooled, and always use a glove or
towel to avoid direct skin contact.
Clear any snow from the hood before
opening.
To open the hood: 1. Pull the hood release lever with the
isymbol. It is on the lower left side
of the instrument panel.
2. Go to the front of the vehicle and locate the secondary release lever under the
front center of the hood. Push the
secondary hood release lever to the right
to release.
3. After you have partially lifted the hood, the gas strut system will automatically
lift the hood and hold it in the fully
open position.
To close the hood: 1. Before closing the hood, be sure all filler caps are on properly, and all tools are
removed.
2. Pull the hood down until the strut system is no longer holding up the hood.
3. Allow the hood to fall. Check to make sure the hood is latched completely.
Repeat this process with additional force
if necessary.{Warning
Do not drive the vehicle if the hood is
not latched completely. The hood could
open fully, block your vision, and cause a
crash. You or others could be injured.
Always close the hood completely before
driving.
The Driver Information Center (DIC) will
display a message if the hood is not fully
closed, and the vehicle is moving. Stop and
turn off the vehicle, check the hood for
obstructions, and close the hood again.
Check to see if the message still appears on
the DIC.