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 - 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
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).

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).

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
8 Keys, Doors, and Windows
{Warning
If the key is unintentionally rotated while
the vehicle is running, the ignition could
be moved out of the RUN position. This
could be caused by heavy items hanging
from the key ring,
or by large or long items attached to the
key ring that could be contacted by the
driver or steering wheel. If the ignition
moves out of the RUN position, the
engine will shut off, braking and steering
power assist may be impacted, and
airbags may not deploy. To reduce the
risk of unintentional rotation of the
ignition key, do not change the way the
ignition key and Remote Keyless Entry
(RKE) transmitter, if equipped, are
connected to the provided key rings.
The ignition key and key rings, and RKE
transmitter, if equipped, are designed to
work together as a system to reduce the
risk of unintentionally moving the key out
of the RUN position. The ignition key has a
small hole to allow attachment of the
provided key ring. It is important that any replacement ignition keys have a small hole.
See your dealer if a replacement key is
required.
The combination and size of the rings that
came with your keys were specifically
selected for your vehicle. The rings are
connected to the key like two links of a
chain to reduce the risk of unintentionally
moving the key out of the RUN position. Do
not add any additional items to the ring
attached to the ignition key. Attach
additional items only to the second ring,
and limit added items to a few essential
keys or small, light items no larger than an
RKE transmitter.
Interference from radio-frequency
identification (RFID) tags may prevent the
key from starting the vehicle. Keep RFID
tags away from the key when starting the
vehicle.
The key is used for the ignition, all door
locks, and the glove box.
If equipped with memory seats, keys 1 and 2
are linked to seating positions of memory 1
or 2. See
Memory Seats 046.
Programming Keys
Follow these procedures to program up to
eight keys to the vehicle.
Programming with Two Recognized Keys
To program a new key:

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 11
Other conditions can affect the performance
of the transmitter. SeeRemote Keyless Entry
(RKE) System 010.
/:Press and releaseQ, then immediately
press and hold
/until the turn signal
lamps flash or for at least four seconds. The
engine may be started from outside the
vehicle using the RKE transmitter. See
Remote Vehicle Start 020.
Q:Press to lock all doors.
If enabled, the turn signal lamps may flash
and/or the horn may sound on the second
press to indicate locking has occurred. If enabled, the horn chirps when
Qis
pressed again within three seconds. See
Vehicle Personalization 0126.
Pressing
Qarms the alarm system. See
Vehicle Alarm System 027.
If equipped with remote mirror folding,
pressing and holding
Qfor one second will
fold the mirrors, if enabled. See Vehicle
Personalization 0126.
K:Press once to unlock only the driver
door. If
Kis pressed again within
three seconds, all remaining doors unlock.
The interior lamps may come on and stay
on for 20 seconds or until the ignition is
turned on.
If enabled, the turn signal lamps flash twice
to indicate unlocking has occurred.
If enabled, the exterior lamps may turn on.
See Vehicle Personalization 0126.
Pressing
Kon the RKE transmitter disarms
the alarm system. See Vehicle Alarm System
0 27.
If equipped with remote mirror folding,
pressing and holding
Kfor one second will
unfold the mirrors, if enabled. See Vehicle
Personalization 0126. Press and hold
Kto remotely open the
windows, if enabled. See Vehicle
Personalization 0126.
x:Press twice quickly to release the
tailgate, if equipped.
7: Press and release to initiate the vehicle
locator. The turn signal lamps flash and the
horn sounds three times.
Press and hold
7for more than
three seconds to activate the panic alarm.
The turn signal lamps flash and the horn
sounds repeatedly for 30 seconds. The alarm
turns off when the ignition is turned on or
7is pressed again. The ignition must be off
for the panic alarm to work.
Programming Transmitters to the Vehicle
Only RKE transmitters programmed to this
vehicle will work. If a transmitter is lost or
stolen, a replacement can be purchased and
programmed through your dealer. Each
vehicle can have up to eight transmitters
programmed to it. See your dealer for
transmitter programming.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 13
2. Press and slide the battery down towardthe pocket of the transmitter in the
direction of the key ring. Do not use a
metal object
3. Remove the battery.
4. Insert the new battery, positive side facing up. Replace with a CR2032 or
equivalent battery.
5. Push together the transmitter back cover top side first, and then the bottom
toward the key ring.
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
The Keyless Access system allows for vehicle
entry when the transmitter is within 1 m
(3 ft). See “Keyless Access Operation” later
in this section.
The RKE transmitter functions may work up
to 60 m (197 ft) away from the vehicle.
Other conditions can affect the performance
of the transmitter. See Remote Keyless Entry
(RKE) System 010.
The key that is part of the RKE transmitter
can be used for all locks.
Remove the key by pressing the button on
the side of the RKE transmitter near the
bottom and pull the key out. Never pull the
key out without pressing the button.
See your dealer if a new transmitter is
needed./: Press and releaseQ, then immediately
press and hold
/until the turn signal
lamps flash or for at least four seconds. The
engine may be started from outside the
vehicle using the RKE transmitter. See
Remote Vehicle Start 020.
Q:Press to lock all doors and the tailgate,
if equipped.
If enabled, the turn signal lamps flash and/
or the horn may sound on the second press
to indicate locking has occurred. If enabled,
the horn chirps when
Qis pressed again
within three seconds. See Vehicle
Personalization 0126.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 17
4. Place the new transmitter in thetransmitter pocket/insert.
5. Press ENGINE START/STOP. When the transmitter is learned, the DIC display
will show that it is ready to program the
next transmitter.
6. Remove the transmitter from the transmitter pocket and press
KorQon
the transmitter.
To program additional transmitters,
repeat Steps 4–6.
When all additional transmitters are
programmed, press and hold ENGINE
START/STOP for approximately
12 seconds to exit programming mode.
7. Return the key back into the transmitter.
Programming without Recognized
Transmitters
If two currently recognized transmitters are
not available, follow this procedure to
program up to eight transmitters. This
feature is not available in Canada. This
procedure will take approximately
30 minutes to complete. The vehicle must
be off and all transmitters to be
programmed must be with you. 1. Remove the vehicle key from the
transmitter.
2. Insert the vehicle key into the key lock cylinder on the driver door handle; then
turn the key counterclockwise, to the
unlock position, five times within
10 seconds.
The DIC displays REMOTE LEARN
PENDING, PLEASE WAIT.
3. Wait for 10 minutes until the DIC displays PRESS ENGINE START BUTTON TO
LEARN, then press ENGINE START/STOP.
The DIC will again display REMOTE LEARN
PENDING, PLEASE WAIT.
4. Repeat Step 3 two additional times. After the third time all previously known
transmitters will no longer work with the
vehicle. Remaining transmitters can be
relearned during the next steps.
The DIC should now display READY FOR
REMOTE # 1.
Transmitter Pocket without Bucket Seats
(Lower Compartment)
Transmitter Pocket with Bucket Seats

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
18 Keys, Doors, and Windows
5. Place the new transmitter in thetransmitter pocket/insert.
6. Press ENGINE START/STOP. When the transmitter is learned, the DIC display
will show that it is ready to program the
next transmitter.
7. Remove the transmitter from the transmitter pocket/insert and press
Kor
Qon the transmitter.
To program additional transmitters,
repeat Steps 5–7.
When all additional transmitters are
programmed, press and hold ENGINE
START/STOP for approximately
12 seconds to exit programming mode.
8. Return the key back into the transmitter.
Starting the Vehicle with a Low
Transmitter Battery
If the transmitter battery is weak or if there
is interference with the signal, the DIC may
display NO REMOTE DETECTED or NO
REMOTE KEY WAS DETECTED PLACE KEY IN
TRANSMITTER POCKET THEN START YOUR
VEHICLE when starting the vehicle.
To start the vehicle:
Transmitter Pocket without Bucket Seats (Lower Compartment)
Transmitter Pocket with Bucket Seats 1. Place the transmitter in the transmitter
pocket/insert.
2. With the vehicle in P (Park) or N (Neutral) press the brake pedal and ENGINE
START/STOP.
Replace the transmitter battery as soon
as possible.
Battery Replacement
{Warning
Never allow children to play with the RKE
transmitter. The transmitter contains a
small battery, which can be a choking
hazard. If swallowed, internal burns can
occur, resulting in severe injury or death.
Seek medical attention immediately if a
battery is swallowed.
{Warning
To avoid personal injury, do not touch
metal surfaces on the RKE transmitter
when it has been exposed to extreme
heat. These surfaces can be hot to the
touch at temperatures above 59 °C (138
°F).

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
20 Keys, Doors, and Windows
Remote Vehicle Start
If equipped with the remote start feature,
the climate control system will come on
when the vehicle is started remotely,
depending on the outside temperature.
The rear defog and heated and ventilated
seats, if equipped, may also come on. See
Heated and Ventilated Front Seats049 and
Vehicle Personalization 0126.
If equipped, the automatic heated steering
wheel may also come on. See Heated
Steering Wheel 096.
Laws in some communities may restrict the
use of remote starters. Check local
regulations for any requirements on remote
starting of vehicles.
Do not use remote start if the vehicle is low
on fuel. The vehicle may run out of fuel.
The vehicle cannot be remote started if:
.The RKE transmitter is inside the vehicle
or if the key is in the ignition.
.The hood is not closed.
.There is an emission control system
malfunction and the lamp is on.
.The ignition is in any mode other
than off.
.The hazard warning flashers are on.
.Two remote starts or a remote start with
an extension have been used.
.The vehicle is not in P (Park).
The engine will turn off during a remote
vehicle start if:
.The coolant temperature gets too high.
.The oil pressure gets low.
The RKE transmitter range may be reduced
while the vehicle is running.
Other conditions can affect the performance
of the transmitter. See Remote Keyless Entry
(RKE) System 010.
Starting the Engine Using Remote Start
1. Press and release
Q.
2. Immediately press and hold
/until the
turn signal lamps flash or for at least
four seconds.
When the vehicle starts, the parking
lamps will turn on. The doors will be
locked and the climate control system
may come on.
The engine will continue to run for
15 minutes. After 30 seconds, repeat
Steps 1 and 2 for a 15-minute time
extension. Turn the ignition on to operate the vehicle.
Extending Engine Run Time
The engine run time can be extended by
15 minutes, for a total of 30 minutes,
if during the first 15 minutes Steps 1 and 2
are repeated while the engine is still
running. An extension can be requested
30 seconds after starting.
A maximum of two remote starts, or a
single start with an extension, is allowed
between ignition cycles.
The vehicle's ignition must be turned on and
then back off to use remote start again.
Canceling a Remote Start
To cancel a remote start, do one of the
following:.Press and hold/until the parking lamps
turn off.
.Turn on the hazard warning flashers.
.Turn the ignition on and then off.