2021 CHEVROLET SILVERADO 2500HD light

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 9
1. Insert the original, already programmedkey in the ignition and turn the
ignition on.
2. Turn the ignition off, and remove the key.
3. Quickly, within five seconds, insert the second original already programmed key
in the ignition and turn the ignition on.
4. Turn the ignition off, and remove the key.
5. Insert the key to be programmed and turn the ignition on within five seconds.
6. After a few seconds, the security light will turn off once the key has been
programmed.
7. Repeat Steps 1–5 if additional keys are to be programmed.
If a key is lost or damaged, see your dealer
to have a new key made.
Programming without Recognized Keys
Program a new key to the vehicle when a
recognized key is not available. Canadian
regulations require that owners see their
dealer.
If two currently recognized keys are not
available, follow this procedure to program
the first key. This procedure will take approximately
30 minutes to complete for the first key.
The vehicle must be off and all of the keys
you wish to program must be with you.
1. Insert the new vehicle key into the ignition.
2. Turn the ignition on. The security light will come on.
3. Wait 10 minutes until the security light turns off.
4. Turn the ignition off.
5. Repeat Steps 2–4 two more times. After the third time, turn the ignition on; the
key is learned and all previously known
keys will no longer work with the
vehicle.
6. To learn a second key, turn the ignition off, insert the second key to be learned,
and turn the ignition on.
After two keys are learned, the remaining
keys can be learned by following the
procedure in “Programming with Two
Recognized Keys.”
The key has a bar-coded key tag that the
dealer or qualified locksmith can use to
make new keys. Store this information in a
safe place, not in the vehicle. See your dealer if a replacement key or
additional key is needed.
If it becomes difficult to turn a key, inspect
the key blade for debris. Periodically clean
with a brush or pick.
If locked out of the vehicle, see
Roadside
Assistance Program 0404.
With an active OnStar or connected service
plan, an OnStar Advisor may remotely
unlock the vehicle. See OnStar Overview
0 412.
Keys (Keyless Access)
{Warning
Leaving children in a vehicle with an
ignition key or Remote Keyless Entry
(RKE) transmitter is dangerous and
children or others could be seriously
injured or killed. They could operate the
power window or other controls or make
the vehicle move. The windows will
function with the key in the ignition or
with the RKE transmitter in the vehicle,
and children or others could be caught in
(Continued)

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 27
Warning (Continued)
hands or other body parts between the
extended power assist step and the
vehicle.
If equipped, the power assist steps will
deploy when the door is opened and
automatically retract three seconds after the
door is closed. The power assist steps will
retract immediately if the vehicle starts
moving.
Disable the power assist steps before jacking
or placing any object under the vehicle. Too
much ice buildup may prevent deployment
of the power assist steps. Check the step
position before exiting the vehicle. If this
happens, disable the power assist steps,
clear the ice, then enable the assist steps
and confirm normal function prior to use.
Keep hands, children, pets, objects, and
clothing clear of the power assist steps
when in motion. The steps will reverse
direction if they encounter an obstruction
when opening or closing. Remove the
obstruction, then open and close the door
on the same side to complete the motion of the assist steps. If the obstruction is not
cleared. the assist steps remain extended
while driving.
To extend both power assist steps
for cleaning, press
jwhile the vehicle is
in P (Park) or N (Neutral). Press
jagain
to retract them. The Driver Information
Center (DIC) will display a message.
Enable/Disable
Press and hold
jfor four seconds to lock
and disable the power assist steps. Press
and hold
jfor four seconds again to
enable them. The DIC will display a
message.
Vehicle Security
This vehicle has theft-deterrent features;
however, they do not make the vehicle
impossible to steal.
Vehicle Alarm System
The indicator light, on the instrument panel
near the windshield, indicates the status of
the system.
Off : Alarm system is disarmed.
On Solid : Vehicle is secured during the
delay to arm the system.
Fast Flash : Vehicle is unsecured. A door or
the hood is open.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
28 Keys, Doors, and Windows
Slow Flash :Alarm system is armed.
Arming the Alarm System
1. Turn off the vehicle.
2. Lock the vehicle in one of two ways:
.Use the RKE transmitter.
.With a door open, pressQon the
interior of the door.
3. After 30 seconds, the alarm system will arm and the indicator light will begin to
slowly flash. Pressing
Qon the RKE
transmitter a second time will bypass
the 30-second delay and immediately
arm the alarm system.
The vehicle alarm system will not arm if the
doors are locked with the key.
If the driver door is opened without first
unlocking with the RKE transmitter, the horn
will chirp and the lights will flash to indicate
pre-alarm. If the vehicle is not started,
or the door is not unlocked by pressing
K
on the RKE transmitter during the 10-second
pre-alarm, the alarm will be activated.
The alarm will also be activated if a
passenger door or the hood is opened
without first disarming the system. When
the alarm is activated, the turn signals flash and the horn sounds for about 30 seconds.
The alarm system will then re-arm to
monitor for the next unauthorized event.
Disarming the Alarm System
To disarm the alarm system or turn off the
alarm if it has been activated:
.PressKon the RKE transmitter.
.Start the vehicle.
To avoid setting off the alarm by mistake:
.Lock the vehicle after all occupants have
exited.
.Always unlock a door with the RKE
transmitter.
Unlocking the driver door with the key
will not disarm the system or turn off the
alarm.
How to Detect a Tamper Condition
IfKis pressed on the RKE transmitter and
the horn chirps three times, an alarm
occurred previously while the alarm system
was armed.
If the alarm has been activated, a message
will appear on the DIC.
Steering Column Lock
If equipped, the steering column lock is a
theft-deterrent device. This feature locks the
steering column when the vehicle is turned
off and the driver door is opened, or when
the driver door is opened and then the
vehicle is turned off. The steering column
unlocks when the vehicle is turned on.
The Driver Information Center (DIC) may
display one of these messages:
.A message to service the steering column
lock indicates that an issue has been
detected with the column lock feature
and the vehicle should be serviced.
.A message that the steering column is
locked indicates that the engine is
running, but the steering column is still
locked. It is normal for the column to be
locked during a remote start, but the
column should unlock after the brake
pedal is pressed and the vehicle is started.
No message will display during a remote
start.
.A message that the steering wheel must
be turned and the vehicle must be started
again indicates that the column lock
mechanism is bound, the column locking
device was unable to unlock the steering