2021 CHEVROLET SILVERADO 2500HD index

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.

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

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
54 Seats and Restraints
Never route the lap or shoulder belt over an
armrest.
{Warning
The seat belt can be pinched if it is
routed under plastic trim on the seat,
such as trim around the rear seatback
folding handle or side airbag. In a crash,
pinched seat belts might not be able to
provide adequate protection. Never allow
seat belts to be routed under plastic trim
pieces.
Lap-Shoulder Belt
All seating positions in the vehicle have a
lap-shoulder belt.The following instructions explain how to
wear a lap-shoulder belt properly.
1. Adjust the seat, if the seat is adjustable, so you can sit up straight. To see how,
see “Seats” in the Index.
2. Pick up the latch plate and pull the belt
across you. Do not let it get twisted.
The lap-shoulder belt may lock if you
pull the belt across you very quickly.
If this happens, let the belt go back
slightly to unlock it. Then pull the belt
across you more slowly.
If the shoulder portion of a passenger
belt is pulled out all the way, the child
restraint locking feature may be engaged. See
Child Restraint Systems
0 71. If this occurs, let the belt go back
all the way and start again. If the
locking feature stays engaged after
letting the belt go back to stowed
position on the seat, move the seat
rearward or recline the seat until the
shoulder belt retractor lock releases.
Engaging the child restraint locking
feature in the front outboard seating
position may affect the passenger
sensing system, if equipped. See
Passenger Sensing System 062.
If the webbing locks in the latch plate
before it reaches the buckle, tilt the latch
plate flat to unlock.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Seats and Restraints 65
6. Restart the vehicle.
The passenger sensing system may or may
not turn off the airbag for a child in a child
restraint depending upon the child’s size.
It is better to secure child restraints in the
rear seat. Consider using another vehicle to
transport the child when a rear seat is not
available. Never put a rear-facing child
restraint in the front seat, even if the ON
indicator is not lit.
If the Off Indicator Is Lit for an
Adult-Sized Occupant
If a person of adult size is sitting in the
front outboard passenger seat, but the OFF
indicator is lit, it could be because that
person is not sitting properly in the seat or that the child restraint locking feature is
engaged. Use the following steps to allow
the system to detect that person and enable
the front outboard passenger frontal airbag:
1. Turn the vehicle off.
2. Remove any additional material from the seat, such as blankets, cushions, seat
covers, seat heaters, or seat massagers.
3. Place the seatback in the fully upright position.
4. Have the person sit upright in the seat, centered on the seat cushion, with legs
comfortably extended.
5. If the shoulder portion of the belt is pulled out all the way, the child restraint
locking feature will be engaged. This
may unintentionally cause the passenger
sensing system to turn the airbag off for
some adult-sized occupants. If this
happens, unbuckle the belt, let the belt
go back all the way, and then buckle the
belt again without pulling the belt out
all the way.
6. Restart the vehicle and have the person remain in this position for two to
three minutes after the ON indicator
is lit.
{Warning
If the front outboard passenger airbag is
turned off for an adult-sized occupant,
the airbag will not be able to inflate and
help protect that person in a crash,
resulting in an increased risk of serious
injury or even death. An adult-sized
occupant should not ride in the front
outboard passenger seat, if the passenger
airbag OFF indicator is lit.
Additional Factors Affecting System
Operation
Seat belts help keep the passenger in
position on the seat during vehicle
maneuvers and braking, which helps the
passenger sensing system maintain the
passenger airbag status. See “Seat Belts”
and “Child Restraints” in the Index for
additional information about the importance
of proper restraint use.
A thick layer of additional material, such as
a blanket or cushion, or aftermarket
equipment such as seat covers, seat heaters,
and seat massagers can affect how well the
passenger sensing system operates. We
recommend that you not use seat covers or
other aftermarket equipment except when

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
154 Infotainment System
Caution
To avoid vehicle damage, unplug all
accessories and disconnect all accessory
cables from the vehicle when not in use.
Accessory cables left plugged into the
vehicle, unconnected to a device, could be
damaged or cause an electrical short if
the unconnected end comes in contact
with liquids or another power source such
as the accessory power outlet.
Playing from a USB
A USB mass storage device can be connected
to the USB port.
Gracenote
When plugging in a USB device, Gracenote
service builds voice tags for music. Voice
tags allow artists, albums with hard to
pronounce names, and nicknames to be used
to play music through voice recognition.
While indexing, infotainment features are
available.My Media Library
MyMedia is only available when more than
one indexed device is connected. It allows
access to content from all indexed media
sources. MyMedia will show as an available
source in the Source page.
USB MP3 Player and USB Devices
The USB MP3 players and USB devices
connected must comply with the USB Mass
Storage Class specification (USB MSC).
to play a USB device:
1. Connect the USB.
2. Press MEDIA on the center stack until the connected device is shown.
Use the following when playing an active
USB source:
r: Touch to play the current media source.
j: Touch to pause playback of the current
media source.
g:
.Press to seek to the beginning of the
current or previous track.
.Press and hold to reverse quickly through
playback. Release to return to playing
speed. Elapsed time displays.
d:
.Press to seek to the next track.
.Press and hold to advance quickly
through playback. Release to return to
playing speed. Elapsed time displays.
Shuffle : Touch the shuffle icon to play
music in random order.
USB Menu
Touch the Menu icon to display the USB
menu. The following may be available:
Shuffle : Touch to play the tracks randomly.
Touch again to stop shuffle.
Tone : Touch + or –to adjust the tone
settings. See AM-FM Radio 0150.
Auto Volume (If Equipped) : This feature
adjusts the volume based on the vehicle
speed. See AM-FM Radio 0150.
Bose AudioPilot Noise Compensation
Technology (If Equipped : This feature
adjusts the volume based on the noise in
the vehicle and speed. See AM-FM Radio
0 150.
USB Browse Menu
When a list of songs, albums, artists,
or other types of media displays, the up and
down arrows and A-Z appear on the left

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Infotainment System 163
2. Search for the destination using One-Box,Voice search, or the Quick Category
icons.
3. Choose search results Along Route, Nearby, or Near Destination.
4. Choose the desired waypoint and touch Add to Trip or replace the current
destination by touching New Destination.
Route options are not available for
waypoints.
Arriving at a Waypoint
When approaching a waypoint, the system
will display a Destination Arrival view. To
continue on to the next destination touch
the Drive to message on the infotainment
display.
If the vehicle passes the waypoint or gets
out of the current route, the system will
automatically reroute back to this waypoint.
At the same time, it will show a Drive to
icon along with the next waypoint address
so the current waypoint can be skipped and
guidance can resume to the next waypoint
or destination. Editing a Waypoint
When waypoints are added during active
guidance, the system allows a stop to be
deleted or the order to be changed. To edit
a waypoint:
1. Touch
A.
2. Touch Edit Destinations.
.Modify destination order by touching
and holding the arrow until it is
highlighted. Drag to move the
waypoint up or down the list.
.Delete a waypoint by touchingY.
A pop-up will appear to confirm
waypoint removal. Once the request
is confirmed, the system will remove
the address from the destinations list.
Touch
zon the top right corner so
the system can recalculate the route.
If there is only one address in the
destinations list, the system will
disable the move and delete
functions. The system will not allow
the final destination to be deleted.
Map Information
Road network attributes are contained in the
map database for map information.
Attributes include information such as street names, street addresses, and turn
restrictions. A detailed area includes all
major highways, service roads, and
residential roads. The detailed areas include
Places of Interest (POIs) such as restaurants,
airports, banks, hospitals, police stations, gas
stations, tourist attractions, and historical
monuments.
If the vehicle does not have an applicable
service plan, the map database may not
include data for newly constructed areas or
map database corrections that are
completed after production. The navigation
system provides full route guidance in the
detailed map areas.
Zoom Control
The zoom control display is shown on the
map view. A few ways to zoom in or
out are:
.Touch + or
–to zoom in or out on
the map.
.Double tap with one finger to zoom in or
single tap with two fingers to zoom out
on the map.
.Use the index finger and thumb to zoom
out by pinching and then zoom in by
spreading those two fingers on the map.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
186 Infotainment System
.HD Radio: This allows HD Radio reception
to be turned on or off.
Touch the controls on the infotainment
display to disable or enable.
.Explicit Content Filter: This setting allows
access to explicit content SiriusXM
channels.
Touch Off or On.
.Manage Phones: Select to connect to a
different phone source, disconnect a
phone, or delete a phone.
.Reset Music Index: This allows the music
index to be reset if you are having
difficulty accessing all of the media
content on your device.
Touch Yes or No.
Climate
Touch and the following may display:
.Auto Fan Speed: This setting specifies the
amount of airflow when the climate
control fan setting is Auto Fan.
Touch Low, Medium, or High.
.Air Quality Sensor: This setting switches
the system into Recirculation Mode based
on the quality of the outside air.
Touch Off, Low Sensitivity, or High
Sensitivity.
.Auto Cooled Seats: This setting
automatically turns on and regulates the
ventilated seats when the cabin
temperature is warm.
Touch the controls on the infotainment
display to disable or enable.
.Auto Heated Seats: This setting
automatically turns on and regulates the
heated seats when the cabin temperature
is cool. The auto heated seats can be
turned off by using the heated seat
controls on the center stack.
Touch the controls on the infotainment
display to disable or enable.
.Auto Defog: This setting automatically
turns the front defogger on when the
vehicle engine is started.
Touch the controls on the infotainment
display to disable or enable.
.Auto Rear Defog: This setting
automatically turns the rear window
defogger on when the vehicle engine is
started.
Touch the controls on the infotainment
display to disable or enable.
Navigation
Touch and the following may display:
.Destination Card Preferences
.Map Preferences
.Route Preferences
.Navigation Voice Control
.Traffic Preferences
.Alert Preferences
.Fuel Grade Preferences
.Manage History
.Predictive Navigation (if equipped)
.About
See Using the Navigation System 0158.
Phone
Touch and the following may display:
.My Number: Displays the cell phone
number of the Bluetooth connected
device.
.Active Call View: Shows active call display
when answering a call.
Touch the controls on the infotainment
display to disable or enable.
.Privacy: Only show call alerts in the
instrument cluster.
Touch Off or On.
.Sort Contacts: Touch to sort by first or
last name.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
264 Driving and Operating
Use regular unleaded gasoline meeting
ASTM specification D4814 with a posted
octane rating of 87—(R+M)/2 —or higher.
Do not use gasoline with a posted octane
rating of less than 87, as this may cause
engine knock and will lower fuel economy.
Prohibited Fuels
Caution
Do not use fuels with any of the
following conditions; doing so may
damage the vehicle and void its
warranty:
.For vehicles that are not FlexFuel, fuel
labeled greater than 15% ethanol by
volume, such as mid-level ethanol
blends (16–50% ethanol), E85,
or FlexFuel.
.Fuel with any amount of methanol,
methylal, ferrocene, and aniline. These
fuels can corrode metal fuel system
parts or damage plastic and rubber
parts.
(Continued)
Caution (Continued)
.Fuel containing metals such as
methylcyclopentadienyl manganese
tricarbonyl (MMT), which can damage
the emissions control system and
spark plugs.
.Fuel with a posted octane rating of
less than the recommended fuel. Using
this fuel will lower fuel economy and
performance, and may decrease the
life of the emissions catalyst.
Fuels in Foreign Countries
The U.S., Canada, and Mexico post fuel
octane ratings in anti-knock index (AKI). For
fuel not to use in a foreign country, see
Prohibited Fuels 0264.
Fuel Additives
TOP TIER Detergent Gasoline is highly
recommended for use with your vehicle.
If your country does not have TOP TIER
Detergent Gasoline, add ACDelco Fuel
System Treatment Plus−Gasoline to the
vehicle’s gasoline fuel tank at every oil
change or 15 000 km (9,000 mi), whichever
occurs first. TOP TIER Detergent Gasoline and
ACDelco Fuel System Treatment Plus −Gasoline will help keep your vehicle’s
engine fuel deposit free and performing
optimally.
E85 or FlexFuel
Vehicles with a yellow fuel sticker on the
fuel door can use either unleaded gasoline
or fuel containing up to 85% ethanol (E85).
All other vehicles should use only the
unleaded gasoline as described in
Recommended Fuel
0263.
The use of E85 or FlexFuel is encouraged
when the vehicle is designed to use it. E85
or FlexFuel is made from renewable sources.
To help locate fuel stations that carry E85 or
FlexFuel, the U.S. Department of Energy has
an alternative fuel website. See
www.afdc.energy.gov/afdc/locator/stations.
E85 or FlexFuel should meet ASTM
Specification D 5798 or CAN/CGSB–3.512 in
Canada. Do not use the fuel if the ethanol
content is greater than 85%. Fuel mixtures
that do not meet ASTM or CGSB
specifications can affect driveability and
could cause the malfunction indicator lamp
to come on.