climate control 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
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
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.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Keys, Doors, and Windows 33
Resetting the Power Folding Mirrors
Reset the power folding mirrors if:
.The mirrors are accidentally obstructed
while folding.
.The mirrors are accidentally manually
folded/unfolded.
.The mirrors will not stay in the unfolded
position.
.The mirrors vibrate at normal driving
speeds.
Fold and unfold the mirrors one time using
the mirror controls to reset them to their
normal position. A noise may be heard
during the resetting of the power folding
mirrors. This sound is normal after a manual
folding operation.
Remote Mirror Folding
If equipped, press and holdQon the RKE
transmitter for approximately one second to
remotely fold the exterior mirrors. Press and
hold
Kon the RKE transmitter for
approximately one second to unfold. See
Remote Keyless Entry (RKE) System
Operation (Key Access) 010 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 013. This feature can be turned on or off. See
Vehicle Personalization
0126.
Heated Mirrors
1REAR : If equipped, the rear window
defogger also heats the outside mirrors.
W: If equipped, press to turn the heated
outside mirrors on or off.
See “Rear Window Defogger” underClimate
Control Systems 0199 or
Dual Automatic Climate Control System
0 201.
Automatic Dimming Mirror
If equipped, the driver outside mirror
automatically adjusts for the glare of the
headlamps from behind. This feature comes
on when the vehicle is started.
Blind Spot Mirrors
If equipped, there is a small convex mirror
built into the upper and outer corner of the
driver outside mirror. It can show objects
that may be in the vehicle's blind zone.
Driving with the Blind Spot Mirror
Actual Mirror View

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Seats and Restraints 51
{Warning
A seat belt that is improperly routed, not
properly attached, or twisted will not
provide the protection needed in a crash.
The person wearing the belt could be
seriously injured. After raising the rear
seatback, always check to be sure that
the seat belts are properly routed and
attached, and are not twisted.
Heated Rear Seats
{Warning
If you cannot feel temperature change or
pain to the skin, the seat heater may
cause burns. See the Warning under
Heated and Ventilated Front Seats049.
If available, the buttons are on the rear of
the center console. To operate, the engine
must be running.
Press
MorLto heat the left or right
outboard seat cushion. An indicator on the
climate control display appears when this
feature is on.
This feature turns on at the highest setting.
With each press of the button, the heated
seat changes to the next lower setting, and
then the off setting. Three lights indicate
the highest setting, and one light indicates
the lowest. If the heated seats are on high,
the level may automatically be lowered
after approximately 30 minutes.
Seat Belts
This section describes how to use seat belts
properly, and some things not to do.
{Warning
Do not let anyone ride where a seat belt
cannot be worn properly. In a crash,
if you or your passenger(s) are not
wearing seat belts, injuries can be much
worse than if you are wearing seat belts.
You can be seriously injured or killed by
hitting things inside the vehicle harder or
by being ejected from the vehicle. In
addition, anyone who is not buckled up
can strike other passengers in the vehicle.
It is extremely dangerous to ride in a
cargo area, inside or outside of a vehicle.
In a collision, passengers riding in these
areas are more likely to be seriously
injured or killed. Do not allow passengers
to ride in any area of the vehicle that is
not equipped with seats and seat belts.
Always wear a seat belt, and check that
all passenger(s) are restrained
properly too.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
98 Instruments and Controls
If the ignition is turned off while the wipers
are performing wipes due to windshield
washing, the wipers continue to run until
they reach the base of the windshield.
Compass
The vehicle may have a compass display on
the Driver Information Center (DIC). The
compass receives its heading and other
information from the Global Positioning
System (GPS) antenna, Electronic Stability
Control (ESC), and vehicle speed information.
The compass system is designed to operate
for a certain number of miles or degrees of
turn before needing a signal from the GPS
satellites. When the compass display shows
CAL, drive the vehicle for a short distance in
an open area where it can receive a GPS
signal. The compass system will
automatically determine when a GPS signal
is restored and provide a heading again.
Clock
Set the time and date using the
infotainment system. See "Time / Date"
underSettings 0181.
Power Outlets
Accessory power outlets can be used to plug
in electrical equipment, such as a cell phone
or MP3 player.
Rear of Front Center Console
The vehicle has one accessory power outlet
under the climate control system and one
accessory power outlet on the rear of the
center console, if equipped, or on the rear of
the bench seat, if equipped.
Lift the cover to access and replace when
not in use.
{Warning
Power is always supplied to the outlets.
Do not leave electrical equipment
plugged in when the vehicle is not in use
because the vehicle could catch fire and
cause injury or death.
Caution
Leaving electrical equipment plugged in
for an extended period of time while the
vehicle is off will drain the battery.
Always unplug electrical equipment when
not in use and do not plug in equipment
that exceeds the maximum 15 amp
rating.
Certain power accessory plugs may not be
compatible with the accessory power outlet
and could overload vehicle or adapter fuses.
If a problem is experienced, see your dealer.
When adding electrical equipment, be sure
to follow the proper installation instructions
included with the equipment. See Add-On
Electrical Equipment 0297.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
126 Instruments and Controls
Follow the instructions given in the
messages. The system displays messages
regarding the following topics:
.Service Messages
.Fluid Levels
.Vehicle Security
.Brakes
.Steering
.Ride Control Systems
.Driver Assistance Systems
.Cruise Control
.Lighting and Bulb Replacement
.Wiper/Washer Systems
.Doors and Windows
.Seat Belts
.Airbag Systems
.Engine and Transmission
.Tire Pressure
.Battery
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays when the vehicle's
propulsion power is reduced. A reduction in
propulsion power can affect the vehicle's
ability to accelerate. If this message is on,but there is no observed reduction in
performance, proceed to your destination.
Under certain conditions the performance
may be reduced the next time the vehicle is
driven. The vehicle may be driven while this
message is on, but maximum acceleration
and speed may be reduced. Anytime this
message stays on, or displays repeatedly,
the vehicle should be taken to your dealer
for service as soon as possible.
Under certain operating conditions,
propulsion will be disabled. Try restarting
after the ignition has been off for
30 seconds.
Vehicle Speed Messages
SPEED LIMITED TO XXX KM/H (MPH)
This message shows that the vehicle speed
has been limited to the speed displayed. The
limited speed is a protection for various
propulsion and vehicle systems, such as
lubrication, thermal, brakes, suspension,
Teen Driver if equipped, or tires.
Vehicle Personalization
The following are all possible vehicle
personalization features. Depending on the
vehicle, some may not be available.For System, Apps, and Personal features and
functions, see
Settings0181.
To access the vehicle personalization menu: 1. Touch the Settings icon on the Home Page of the infotainment display.
2. Touch Vehicle to display a list of available options.
3. Touch to select the desired feature setting.
4. Touch
9orRto turn a feature off or on.
5. Touch
zto go to the top level of the
Settings menu.
The menu may contain the following:
Rear Seat Reminder
This allows for a chime and a message when
the rear door has been opened before or
during operation of the vehicle.
Touch Off or On.
Climate and Air Quality
Touch and the following may display:
.Auto Fan Speed
.Auto Defog
.Auto Rear Defog

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Instruments and Controls 127
Auto Fan Speed
This setting specifies the amount of airflow
when the climate control fan setting is
Auto Fan.
Touch Low, Medium, or High.
Auto Defog
This setting automatically directs air to the
windshield to assist in defogging, based on
temperature and humidity conditions.
Touch Off or On.
Auto Rear Defog
This setting automatically turns the rear
defogger on based on temperature and
humidity conditions.
Touch Off or On.
Collision/Detection Systems
Touch and the following may display:
.Alert Type
.Forward Collision System
.Lane Change Alert
.Park Assist
.Rear Camera Park Assist Symbols
.Rear Cross Traffic AlertAlert Type
This feature sets the type of alert from the
driver assistance systems to help avoid
crashes.
Touch Beeps or Safety Alert Seat.
Forward Collision System
This setting can alert of a potential crash
with a detected vehicle ahead and can apply
brakes to help reduce a collision’s severity.
Touch Off, Alert, or Alert and Brake.
Lane Change Alert
This allows the feature to be turned on or
off. See
Lane Change Alert (LCA) 0261.
Touch Off or On.
Park Assist
This allows the feature to be turned on or
off. See Assistance Systems for Parking or
Backing 0249.
Select Off, On, or On with Towbar.
Rear Camera Park Assist Symbols
This setting enables the Rear Camera Park
Assist Symbols. See Assistance Systems for
Parking or Backing 0249.
Touch Off or On. Rear Cross Traffic Alert
This allows the Rear Cross Traffic Alert
feature to be turned on or off. See
Assistance Systems for Parking or Backing
0
249.
Touch Off or On.
Comfort and Convenience
Touch and the following may display:
.Chime Volume
.Reverse Tilt Mirror
.Remote Mirror Folding
Chime Volume
This determines the chime volume level.
Touch the controls on the infotainment
display to adjust the volume.
Reverse Tilt Mirror
When on, the driver, passenger, or both
driver and passenger outside mirrors will tilt
downward when the vehicle is shifted into
R (Reverse) to improve visibility of the
ground near the rear wheels. They may
move from their tilted position when the
vehicle is shifted out of R (Reverse) or
turned off. See Reverse Tilt Mirrors 034.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
142 Lighting
When the battery's state of charge is low,
the voltage is raised slightly to quickly bring
the charge back up. When the state of
charge is high, the voltage is lowered
slightly to prevent overcharging. The
voltmeter gauge or the voltage display on
the Driver Information Center (DIC),
if equipped, may show the voltage moving
up or down. This is normal. If there is a
problem, an alert will be displayed.
The battery can be discharged at idle if the
electrical loads are very high. This is true for
all vehicles. This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all the power that
is needed for very high electrical loads.
A high electrical load occurs when several of
the following are on, such as: headlamps,
high beams, fog lamps, rear window
defogger, climate control fan at high speed,
heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory
power outlets.EPM works to prevent excessive discharge of
the battery. It does this by balancing the
generator's output and the vehicle's
electrical needs. It can increase engine idle
speed to generate more power, whenever
needed. It can temporarily reduce the power
demands of some accessories.
Normally, these actions occur in steps or
levels, without being noticeable. In rare
cases at the highest levels of corrective
action, this action may be noticeable to the
driver. If so, a DIC message might be
displayed and it is recommended that the
driver reduce the electrical loads as much as
possible.
Battery Power Protection
This feature shuts off the dome and reading
lamps, if they are left on for more than
10 minutes after the ignition is turned off.
The cargo lamp shuts off after 20 minutes.
This prevents the battery from
running down.
Exterior Lighting Battery Saver
The exterior lamps turn off about 10 minutes
after the ignition is turned off, if the parking
lamps or headlamps have been manually
left on. This protects against draining the
battery. To restart the 10-minute timer, turn
the exterior lamp control to the
Oposition
and then back to the
;or2position.
To keep the lamps on for more than
10 minutes, the ignition must be on or in
ACC/ACCESSORY.

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.