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Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 5/14/21
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Keys, Doors, and Windows . . . . . . . . . . . . . . . 7
Seats and Restraints . . . . . . . . . . . . . . . . . . . . . 42
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Instruments and Controls . . . . . . . . . . . . . . . 95
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Infotainment System . . . . . . . . . . . . . . . . . . . 143
Climate Controls . . . . . . . . . . . . . . . . . . . . . . . 199
Driving and Operating . . . . . . . . . . . . . . . . . 206
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Service and Maintenance . . . . . . . . . . . . . . . 383
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . 397
Customer Information . . . . . . . . . . . . . . . . . . 401
Reporting Safety Defects . . . . . . . . . . . . . . 409
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
Connected Services . . . . . . . . . . . . . . . . . . . . . 417
Index . . . . . . . . . . . . . . . . . . . . . . . . . . 420
Introduction
The names, logos, emblems, slogans, vehicle
model names, and vehicle body designs
appearing in this manual including, but not
limited to, GM, the GM logo, CHEVROLET,
the CHEVROLET Emblem, SILVERADO, and Z71
are trademarks and/or service marks of
General Motors LLC, its subsidiaries,
affiliates, or licensors.
For vehicles first sold in Canada, substitute
the name“General Motors of Canada
Company” for Chevrolet Motor Division
wherever it appears in this manual.
This manual describes features that may or
may not be on the vehicle because of
optional equipment that was not purchased
on the vehicle, model variants, country
specifications, features/applications that may not be available in your region, or changes
subsequent to the printing of this owner’s
manual.
If the vehicle has the Duramax diesel
engine, see the Duramax diesel supplement
for additional and specific information on
this engine.
Refer to the purchase documentation
relating to your specific vehicle to confirm
the features.
Keep this manual in the vehicle for quick
reference.
Canadian Vehicle Owners
A French language manual can be obtained
from your dealer, at www.helminc.com,
or from:
Propriétaires Canadiens
On peut obtenir un exemplaire de ce guide
en français auprès du concessionnaire ou
à l'adresse suivante:
Litho in U.S.A.
Part No. 84744493 C Third Printing©2021 General Motors LLC. All Rights Reserved.
Page 3 of 433

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
2 Introduction
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
USA
Using this Manual
To quickly locate information about the
vehicle, use the Index in the back of the
manual. It is an alphabetical list of what is
in the manual and the page number where
it can be found.
Danger, Warning, and Caution
Warning messages found on vehicle labels
and in this manual describe hazards and
what to do to avoid or reduce them.
{Danger
Danger indicates a hazard with a high
level of risk which will result in serious
injury or death.
{Warning
Warning indicates a hazard that could
result in injury or death.
Caution
Caution indicates a hazard that could
result in property or vehicle damage.
A circle with a slash through it is a safety
symbol which means“Do not,” “Do not do
this,” or“Do not let this happen.”
Symbols
The vehicle has components and labels that
use symbols instead of text. Symbols are
shown along with the text describing the
operation or information relating to a
specific component, control, message, gauge,
or indicator.
M:Shown when the owner’s manual has
additional instructions or information.
*: Shown when the service manual has
additional instructions or information.
0: Shown when there is more information
on another page — “see page.” Vehicle Symbol Chart
Here are some additional symbols that may
be found on the vehicle and what they
mean. See the features in this manual for
information.
u:
Air Conditioning System
G:Air Conditioning Refrigerant Oil
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
$:Brake System Warning Light
9:Dispose of Used Components Properly
P:Do Not Apply High Pressure Water
B:Engine Coolant Temperature
_:Flame/Fire Prohibited
H: Flammable
[:Forward Collision Alert
R:Fuse Block Cover Lock Location
+:Fuses
j:ISOFIX/LATCH System Child Restraints
Page 4 of 433
Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Introduction 3
Q:Keep Fuse Block Covers Properly
Installed
|: Lane Change Alert
@:Lane Departure Warning
A:Lane Keep Assist
*: Malfunction Indicator Lamp
::Oil Pressure
X:Park Assist
~:Pedestrian Ahead Indicator
O:Power
7:Rear Cross Traffic Alert
I:Registered Technician
/:Remote Vehicle Start
h:Risk of Electrical Fire
>:Seat Belt Reminders
I:Side Blind Zone Alert
7:Tire Pressure Monitor
d:Traction Control/StabiliTrak/Electronic
Stability Control (ESC)
a: Under Pressure
V: Vehicle Ahead Indicator
Page 5 of 433
Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
4 Introduction
Instrument Panel Overview
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Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Introduction 5
1. Tow/Haul Mode (On Some Models). SeeDriver Mode Control 0244.
Automatic Transfer Case Control (If
Equipped). See Four-Wheel Drive 0236.
Driver Mode Control 0244 (If Equipped).
2. Air Vents 0204.
3. Turn Signal Lever. See Turn and
Lane-Change Signals 0138.
Windshield Wiper/Washer 097.
4. Head-Up Display (HUD) 0123 (If
Equipped).
5. Instrument Cluster 0102.
6. Shift Lever. See Automatic Transmission
0 232.
Range Selection Mode. See Manual Mode
0 235.
7. Light Sensor. See Automatic Headlamp
System 0136.
8. Infotainment Controls. See Overview
0 144.
9. Climate Control Systems 0199 (If
Equipped).
Dual Automatic Climate Control System
0 201 (If Equipped).
10. Heated and Ventilated Front Seats 049
(If Equipped). 11.XPark Assist Switch (If Equipped). See
Assistance Systems for Parking or Backing
0 249.
gTraction Control/Electronic Stability
Control 0242.
|Hazard Warning Flashers 0137.
@Lane Departure Warning (LDW) 0262
(If Equipped).
5Hill Descent Control Switch (If
Equipped). See Hill Descent Control (HDC)
0 244.
jPower Assist Steps 026 (If
Equipped).
5Power Release Tailgate (If
Equipped). See Tailgate023.
ADC/AC Switch. See Power Outlets
0 98.
LExpress Window Down Button (If
Equipped). See Power Windows 038.
Tow/Haul Mode 0235 (On Some
Models).
Exhaust Brake (If Equipped). See Duramax
Diesel Supplement.
Power Take-Off (PTO) (If Equipped). See
Duramax Diesel Supplement. 12. Power Outlet (Alternating Current) (If
Equipped). See Power Outlets098.
13. Power Outlets 098.
14. USB Port 0153.
15. Wireless Charging 099 (If Equipped).
16. Trailer Brake Control Panel (If Equipped). See“Integrated Trailer Brake Control
System” underTowing Equipment 0276.
17. ENGINE START/STOP. See Ignition
Positions (Keyless Access) 0226 or
Ignition Positions (Key Access) 0224.
18. Steering Wheel Controls 096 (If
Equipped).
Driver Information Center (DIC) Controls.
See Driver Information Center (DIC) (Base
Level) 0119 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0120.
19. Horn 097.
20. Hood Release. See Hood0302.
21. Steering Wheel Adjustment 096 (Out
of View).
22. Cruise Control 0246.
Forward Collision Alert (FCA) System
0 257 (If Equipped).
Heated Steering Wheel 096 (If
Equipped).
Page 7 of 433
Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
6 Introduction
23. Data Link Connector (DLC) (Out of View).SeeMalfunction Indicator Lamp (Check
Engine Light) 0111.
24. Electric Parking Brake 0240.
25. Fog Lamps 0138 (If Equipped).
Instrument Panel Illumination Control
0 140.
Exterior Cargo Lamps 0139.
Exterior Lamp Controls 0134.
Task Lighting 0139 (If Equipped).
Page 8 of 433

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 7
Keys, Doors, and
Windows
Keys and Locks
Keys (Key Access) . . . . . . . . . . . . . . . . . . . . . . . . 7
Keys (Keyless Access) . . . . . . . . . . . . . . . . . . . . 9
Remote Keyless Entry (RKE) System . . . . 10
Remote Keyless Entry (RKE) SystemOperation (Key Access) . . . . . . . . . . . . . . . 10
Remote Keyless Entry (RKE) System Operation (Keyless Access) . . . . . . . . . . . . 13
Remote Vehicle Start . . . . . . . . . . . . . . . . . . . 20
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Power Door Locks . . . . . . . . . . . . . . . . . . . . . . . 22
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 22
Automatic Door Locks . . . . . . . . . . . . . . . . . . 22
Lockout Protection . . . . . . . . . . . . . . . . . . . . . . 22
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Power Assist Steps . . . . . . . . . . . . . . . . . . . . . 26
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . 27
Vehicle Alarm System . . . . . . . . . . . . . . . . . . 27
Steering Column Lock . . . . . . . . . . . . . . . . . . 28
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Immobilizer Operation . . . . . . . . . . . . . . . . . . 29
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 30
Manual Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 30
Trailer-Tow Mirrors . . . . . . . . . . . . . . . . . . . . . 30
Power Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 32
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 33
Automatic Dimming Mirror . . . . . . . . . . . . . 33
Blind Spot Mirrors . . . . . . . . . . . . . . . . . . . . . . 33
Reverse Tilt Mirrors . . . . . . . . . . . . . . . . . . . . . 34
Interior Mirrors
Interior Rearview Mirrors . . . . . . . . . . . . . . . 34
Manual Rearview Mirror . . . . . . . . . . . . . . . . 34
Automatic Dimming Rearview Mirror . . . 34
Rear Camera Mirror . . . . . . . . . . . . . . . . . . . . 34
Truck Bed Camera Rearview Mirror . . . . . 37
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Manual Windows . . . . . . . . . . . . . . . . . . . . . . . 38
Power Windows . . . . . . . . . . . . . . . . . . . . . . . . 38
Rear Windows . . . . . . . . . . . . . . . . . . . . . . . . . 40
Sun Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Keys and Locks
Keys (Key Access)
{Warning
Leaving children in a vehicle with the
ignition key is dangerous and children or
others could be seriously injured or killed.
They could operate the power windows
or other controls or make the vehicle
move. The windows will function with
the keys in the ignition, and children or
others could be caught in the path of a
closing window. Do not leave children in
a vehicle with the ignition key.