engine CHEVROLET SILVERADO 2500HD 2021 Owner's Manual

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
394 Service and Maintenance
UsageFluid/Lubricant
Key Lock Cylinders, Hood Hinges, Body Door Hinge Pins, Tailgate Hinge and Linkage, Fuel Door Hinge, Tailgate Handle Pivot Points, Hinges, Latch Bolt, and Linkage Multi-Purpose Lubricant, Superlube. See your dealer.
Transfer Case (Four-Wheel Drive) DEXRON-VI Automatic Transmission Fluid. Windshield Washer Automotive windshield washer fluid that meets regional freeze protection requirements.
Maintenance Replacement Parts
Replacement parts identified below by name, part number, or specification can be obtained from your dealer.
If the vehicle has a diesel engine, see the Duramax diesel supplement.
Part GM Part Number ACDelco Part Number
Engine Air Cleaner/Filter
IWith high capacity air cleaner 84121219 A3244C
IWithout high capacity air cleaner 84121217 A3246C
Oil Filter 12690385 PF63E
Passenger Compartment Air Filter 13508023 CF185
Spark Plugs 12622441 41-114

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Technical Data 397
Technical Data
Vehicle Identification
Vehicle Identification Number (VIN) . . . 397
Service Parts Identification . . . . . . . . . . . . 397
Vehicle Data
Capacities and Specifications . . . . . . . . . . 398
Engine Drive Belt Routing . . . . . . . . . . . . . 400
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 0398 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.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
398 Technical Data
Vehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and Lubricants0393.
If the vehicle has a diesel engine, see the Duramax diesel supplement.
Application Capacities
Metric English
Air Conditioning Refrigerant For the air conditioning system refrigerant type and charge amount, see the refrigerant label under the hood. See yourdealer for more information.
Engine Cooling System* 14.6 L 15.4 qt
Engine Oil with Filter 7.6 L 8.0 qt
Fuel Tank
I2500 Series and 3500 Series Standard Box (Except Double Cab Diesel) 136.3 L 36.0 gal
I2500 Series and 3500 Series Standard Box (Double Cab Diesel) 111.3 L 29.4 gal
I2500 Series and 3500 Series Long Box (Except Regular Cab Diesel) 136.3 L 36.0 gal
I2500 Series and 3500 Series Long Box (Regular Cab Diesel) 106.0 L 28.0 gal

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Technical Data 399
ApplicationCapacities
Metric English
I3500 Series Chassis Cab –Front Tank 89.0 L
23.5 gal
I3500 Series Chassis Cab –Rear Tank 151.4 L
40.0 gal
Transfer Case Fluid 2.3 L2.4 qt
Hydraulic Power Steering Fluid 2.0 L2.1 qt
Wheel Nut Torque 190Y 140 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this manual. Recheck fluid level
after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeSpark Plug Gap
6.6L V8 (L8T) 70.95–1.10 mm (0.037–0.043 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the spark plug.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
400 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)

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
408 Customer Information
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 seeRoadside
Assistance Program 0404.
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? 061.
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
with that company. In such cases, you can
have control of the repair and parts choices
as long as the cost stays within reasonable
limits.
Publication Ordering Information
Service Manuals
Service manuals have the diagnosis and
repair information on the engine,
transmission, axle, suspension, brakes,
electrical system, steering system, body, etc.
Customer Literature
Owner’s manuals are written specifically for
owners and are intended to provide basic
operational information about the vehicle.
The owner’s manual includes the
Maintenance Schedule for all models.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
410 Customer Information
and notify General Motors of Canada
Company. Call Transport Canada at
1-800-333-0510; go to:
www.tc.gc.ca/recalls (English)
www.tc.gc.ca/rappels (French)
or write to:
Transport Canada
Motor Vehicle Safety Directorate
Defect Investigations and Recalls
Division
80 Noel Street
Gatineau
,QC J8Z 0A1
Reporting Safety Defects to
General Motors
In addition to notifying NHTSA (or Transport
Canada) in a situation like this, notify
General Motors.
In the U.S., call 1-800-222-1020, or write:
Chevrolet Motor Division
Chevrolet Customer Assistance Center
P.O. Box 33170
Detroit, MI 48232-5170
In Canada, call 1-800-263-3777 (English) or
1-800-263-7854 (French), or write:General Motors of Canada Company
Customer Care Centre, Mail Code:
CA1-163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
In Mexico, call 800-466-0811 or
800-508-0000.
In other Central America and Caribbean
Countries, call 52-555-901-2369.
Vehicle Data Recording and
Privacy
The vehicle has a number of computers that
record information about the vehicle’s
performance and how it is driven or used.
For example, the vehicle uses computer
modules to monitor and control engine and
transmission performance, to monitor the
conditions for airbag deployment and
deploy them in a crash, and, if equipped, to
provide antilock braking to help the driver
control the vehicle. These modules may
store data to help the dealer technician
service the vehicle or to help GM improve
safety or features. Some modules may also
store data about how the vehicle is
operated, such as rate of fuel consumption
or average speed. These modules may retain
personal preferences, such as radio presets,
seat positions, and temperature settings.
Cybersecurity
GM collects information about the use of
your vehicle including operational and safety
related information. We collect this
information to provide, evaluate, improve,
and troubleshoot our products and services
and to develop new products and services.
The protection of vehicle electronics systems
and customer data from unauthorized
outside electronic access or control is
important to GM. GM maintains appropriate
security standards, practices, guidelines and
controls aimed at defending the vehicle and
the vehicle service ecosystem against
unauthorized electronic access, detecting
possible malicious activity in related
networks, and responding to suspected
cybersecurity incidents in a timely,
coordinated and effective manner. Security
incidents could impact your safety or
compromise your private data. To minimize
security risks, please do not connect your
vehicle electronic systems to unauthorized
devices or connect your vehicle to any
unknown or untrusted networks (such as
Bluetooth, WIFI or similar technology). In

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
OnStar 413
.Receive a Diagnostic check of the vehicle's
key operating systems.
.Receive Roadside Assistance.
.Manage Wi-Fi Settings, if equipped.
Press
>to get a priority connection to an
OnStar Advisor available 24/7 to:
.Get help for an emergency.
.Be a Good Samaritan or respond to an
AMBER Alert.
.Get assistance in severe weather or other
crisis situations and find evacuation
routes.
OnStar Services
Emergency
Emergency Services require an active safety
and security plan. With Automatic Crash
Response, built-in sensors can automatically
alert a specially trained OnStar Advisor who
is immediately connected in to the vehicle
to help.
Press
>for a priority connection to an
OnStar Advisor who can contact emergency
service providers, direct them to your exact
location, and relay important information. With OnStar Crisis Assist, specially trained
Advisors are available 24 hours a day, 7 days
a week, to provide a central point of
contact, assistance, and information during a
crisis.
With Roadside Assistance, Advisors can
locate a nearby service provider to help with
a flat tire, a battery jump, or an empty
gas tank.
Security
If equipped, OnStar provides these services:
.With Stolen Vehicle Assistance, OnStar
Advisors can use GPS to pinpoint the
vehicle and help authorities quickly
recover it.
.With Remote Ignition Block, if equipped,
OnStar can block the engine from being
restarted.
.With Stolen Vehicle Slowdown,
if equipped, OnStar can work with law
enforcement to gradually slow the
vehicle down.
Theft Alarm Notification
If equipped, if the doors are locked and the
vehicle alarm sounds, a notification by text,
e-mail, or phone call will be sent. If the
vehicle is stolen, an OnStar Advisor can work
with authorities to recover the vehicle.
OnStar Additional
Information
In-Vehicle Audio Messages
Audio messages may play important
information at the following times:
.Prior to vehicle purchase. PressQto
set up an account.
.After change in ownership and at
90 days.
Transferring Service
PressQto request account transfer
eligibility information. The Advisor can
cancel or change account information.
Selling/Transferring the Vehicle
Call 1-888-4ONSTAR (1-888-466-7827)
immediately to terminate your OnStar or
connected services if the vehicle is disposed
of, sold, transferred, or if the lease ends.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
420 Index
IndexA
Accessories and Modifications . . . . . . . . . . . 302
Accessory Power . . . . . . . . . . . . . . . . . . . . . . . . . 229
Add-On Electrical Equipment . . . . . . . . . . . . . 297
Adding a Snow Plow or SimilarEquipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Additional Information OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Additional Maintenance and Care . . . . . . . . 390
Adjustments Lumbar, Front Seats . . . . . . . . . . . . . . . . . . . . 45
Agreements Trademarks and License . . . . . . . . . . . . . . . 190
Air Cleaner/Filter, Engine . . . . . . . . . . . . . . . . 309
Air Conditioning . . . . . . . . . . . . . . . . . . . . .199, 201
Air Filter
Life System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Air Filter, Passenger Compartment . . . . . . . 204
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
How Does an Airbag Restrain? . . . . . . . . . . 61
Passenger Sensing System . . . . . . . . . . . . . . 62
What Makes an Airbag Inflate? . . . . . . . . . 61
What Will You See after an AirbagInflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
When Should an Airbag Inflate? . . . . . . . . 60
Where Are the Airbags? . . . . . . . . . . . . . . . . 59 Airbags
Adding Equipment to the Vehicle . . . . . . . 66
Passenger Status Indicator . . . . . . . . . . . . . 110
Readiness Light . . . . . . . . . . . . . . . . . . . . . . . . 110
Servicing Airbag-Equipped Vehicles . . . . . . 66
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Alarm
Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . 27
Alert Lane Change . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Side Blind Zone (SBZA) . . . . . . . . . . . . . . . . . 260
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 337
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 337
AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Antenna Fixed Mast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Multi-band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Antilock Brake System (ABS) . . . . . . . . . . . . . 240 Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
Apple CarPlay and Android Auto . . . . . . . . . 180
Assistance Program, Roadside . . . . . . . . . . . . 404
Assistance Systems for Driving . . . . . . . . . . 257
Assistance Systems for Parking and Backing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Index 421
AudioBluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . . . . . . . . 33
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Emergency Braking (AEB) . . . . . . . . . . . . . . 259
Headlamp System . . . . . . . . . . . . . . . . . . . . . 136
Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Transmission Fluid . . . . . . . . . . . . . . . . . . . . . 308
Automatic Transmission Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . 235
Shift Lock Control Function Check . . . . . . 322
Auxiliary Roof Mounted Lamp . . . . . . . . . . . . . . . . . . . 139
Auxiliary Jack . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Avoiding Untrusted Media Devices . . . . . . . . 153
Axle, Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Axle, Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
B
Battery Exterior Lighting Battery Saver . . . . . . . . 142
Load Management . . . . . . . . . . . . . . . . . . . . . . 141
Power Protection . . . . . . . . . . . . . . . . . . . . . . 142
Battery - North America . . . . . . . . . . . . .318, 367
Blade Replacement, Wiper . . . . . . . . . . . . . . . 322
Blind Spot Mirrors . . . . . . . . . . . . . . . . . . . . . . . . .33 Bluetooth
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 175, 176
Bluetooth Audio . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Brake Parking, Electric . . . . . . . . . . . . . . . . . . . . . . . . 240
System Warning Light . . . . . . . . . . . . . . . . . . 113
Brake Pad Life System . . . . . . . . . . . . . . . . . . . 316
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Antilock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Pad Life System . . . . . . . . . . . . . . . . . . . . . . . 316
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Automatic Emergency (AEB) . . . . . . . . . . . 259
Break-In, New Vehicle . . . . . . . . . . . . . . . . . . . . 223
Bulb Replacement Center High-Mounted Stoplamp(CHMSL) and Cargo Lamp . . . . . . . . . . . . 327
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 325
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . 324
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Headlamps, Front Turn Signal, Sidemarker, and Parking Lamps . . . . . . 325
License Plate Lamps . . . . . . . . . . . . . . . . . . . 328
Taillamps, Turn Signal, Stoplamps, and Back-up Lamps . . . . . . . . . . . . . . . . . . 326
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . . . . 351
C
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
California Perchlorate Materials Requirements . . . 301
California Proposition
65 Warning . . . . . . . . . . . . . . . . . . .301, 318, 367, Back Cover
Camera Truck Bed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Canadian Vehicle Owners . . . . . . . . . . . . . . . . . . . 1
Capacities and Specifications . . . . . . . . . . . . . 398
Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 232
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 215
Cargo Tie-Downs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Caution, Danger, and Warning . . . . . . . . . . . . . .2
Center Console Storage . . . . . . . . . . . . . . . . . . . 92
Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp . . . . . . . . . . . . . . 327
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Charging System Light . . . . . . . . . . . . . . . . . . . . 111
Check Engine Light (Malfunction Indicator) . . . . 111