2021 CHEVROLET SILVERADO 2500HD maintenance

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
Seats and Restraints 67
system from properly turning off the
passenger airbag(s). SeePassenger Sensing
System 062.
If the vehicle has rollover roof-rail airbags,
see Different Size Tires and Wheels 0352 for
additional important information.
If a snow plow is added to the vehicle, the
airbags should still work properly. The
airbag systems were designed to work
properly under a wide range of conditions,
including snow plowing with vehicles that
have the optional snow plow prep package
(RPO VYU). Do not change or defeat the
snow plow's “tripping mechanism.” If you
do, it can damage the snow plow and the
vehicle, and may cause an airbag
deployment.
If the vehicle must be modified because you
have a disability and have questions about
whether the modifications will affect the
vehicle's airbag system, or if you have
questions about whether the airbag system
will be affected if the vehicle is modified for
any other reason, call Customer Assistance.
See Customer Assistance Offices 0403.Airbag System Check
The airbag system does not need regularly
scheduled maintenance or replacement.
Make sure the airbag readiness light is
working. See Airbag Readiness Light 0110.
Caution
If an airbag covering is damaged, opened,
or broken, the airbag may not work
properly. Do not open or break the airbag
coverings. If there are any opened or
broken airbag coverings, have the airbag
covering and/or airbag module replaced.
For the location of the airbags, see Where
Are the Airbags? 059. See your dealer
for service.
Replacing Airbag System Parts
after a Crash
{Warning
A crash can damage the airbag systems
in the vehicle. A damaged airbag system
may not properly protect you and your
passenger(s) in a crash, resulting in
serious injury or even death. To help (Continued)
Warning (Continued)
make sure the airbag systems are
working properly after a crash, have
them inspected and any necessary
replacements made as soon as possible.
If an airbag inflates, you will need to
replace airbag system parts. See your dealer
for service.
If the airbag readiness light stays on after
the vehicle is started or comes on when you
are driving, the airbag system may not work
properly. Have the vehicle serviced right
away. See Airbag Readiness Light 0110.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
108 Instruments and Controls
indicates oil pressure outside the normal
operating range, check the vehicle's oil as
soon as possible.
SeeEngine Oil 0305.
Caution
Lack of proper engine oil maintenance
can damage the engine. Driving with the
engine oil low can also damage the
engine. The repairs would not be covered
by the vehicle warranty. Check the oil
level as soon as possible. Add oil if
required, but if the oil level is within the
operating range and the oil pressure is
still low, have the vehicle serviced.
Always follow the maintenance schedule
for changing engine oil.
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
Engine Coolant Temperature
Gauge
Uplevel Metric Shown, Base Level and Midlevel Similar
Uplevel English Shown, Base Level and Midlevel Similar
This gauge measures the temperature of the
vehicle's engine coolant.
While driving under normal operating
conditions, if the needle moves into the red
warning area, the engine is too hot. Pull off
the road, stop the vehicle, and turn off the
engine as soon as possible.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
112 Instruments and Controls
Caution
If the vehicle is driven continually with
this light on, the emission control system
may not work as well, the fuel economy
may be lower, and the vehicle may not
run smoothly. This could lead to costly
repairs that might not be covered by the
vehicle warranty.
Caution
Modifications to the engine, transmission,
exhaust, intake, or fuel system, or the
use of replacement tires that do not
meet the original tire specifications, can
cause this light to come on. This could
lead to costly repairs not covered by the
vehicle warranty. This could also affect
the vehicle’s ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications0302.
If the light is flashing : A malfunction has
been detected that could damage the
emission control system and increase vehicle
emissions. Diagnosis and service may be
required. To help prevent damage, reduce vehicle
speed and avoid hard accelerations and
uphill grades. If towing a trailer, reduce the
amount of cargo being hauled as soon as
possible.
If the light continues to flash, find a safe
place to park. Turn the vehicle off and wait
at least 10 seconds before restarting the
engine. If the light is still flashing, follow
the previous guidelines and see your dealer
for service as soon as possible.
If the light is on steady :
A malfunction has
been detected. Diagnosis and service may be
required.
Check the following:
.If fuel has been added to the vehicle
using the capless funnel adapter, make
sure that it has been removed. See
“Filling the Tank with a Portable Gas Can”
under Filling the Tank (Pickup Model)
0 265 or
Filling the Tank (Chassis Cab and Box
Delete Models) 0266. The diagnostic
system can detect if the adapter has been
left installed in the vehicle, allowing fuel
to evaporate into the atmosphere. A few
driving trips with the adapter removed
may turn off the light.
.Poor fuel quality can cause inefficient
engine operation and poor driveability,
which may go away once the engine is
warmed up. If this occurs, change the fuel
brand. It may require at least one full
tank of the proper fuel to turn the light
off. See Recommended Fuel 0263.
If the light remains on, see your dealer.
Emissions Inspection and Maintenance
Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument panel to
the left of the steering wheel. Connecting
devices that are not used to perform an
Emissions Inspection/Maintenance test or to
service the vehicle may affect vehicle

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Instruments and Controls 117
If this happens, pull over and turn off the
engine as soon as possible. SeeEngine
Overheating 0312.
Driver Mode Control Light
This light comes on when Snow/Ice Mode is
selected.
This light comes on when Off-Road Mode is
selected.
See Driver Mode Control 0244.
Tire Pressure Light
For vehicles with the Tire Pressure Monitor
System (TPMS), this light comes on briefly
when the engine is started. It provides
information about tire pressures and
the TPMS.
When the Light Is On Steady
This indicates that one or more of the tires
are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display. Stop as
soon as possible, and inflate the tires to the
pressure value shown on the Tire and
Loading Information label. See Tire Pressure
0 341.
When the Light Flashes First and Then Is On
Steady
If the light flashes for about a minute and
then stays on, there may be a problem with
the TPMS. If the problem is not corrected, the light will come on at every ignition
cycle. See
Tire Pressure Monitor Operation
0 343.
Engine Oil Pressure Light (Uplevel
Cluster)
Caution
Lack of proper engine oil maintenance
can damage the engine. Driving with the
engine oil low can also damage the
engine. The repairs would not be covered
by the vehicle warranty. Check the oil
level as soon as possible. Add oil if
required, but if the oil level is within the
operating range and the oil pressure is
still low, have the vehicle serviced.
Always follow the maintenance schedule
for changing engine oil.
This light should come on briefly as the
engine is started. If it does not come on,
have the vehicle serviced by your dealer.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
120 Instruments and Controls
Tire Pressure
Turn the trip odometer reset stem until a
vehicle with the approximate pressures of all
four tires displays. Tire pressure is displayed
in either kilopascal (kPa) or in pounds per
square inch (psi).
SeeTire Pressure Monitor System 0342 and
Tire Pressure Monitor Operation 0343.
Remaining Oil Life
Turn the trip odometer reset stem until
REMAINING OIL LIFE displays. An estimate of
the oil's remaining useful life is shown.
REMAINING OIL LIFE 99% means 99% of the
current oil life remains.
When the remaining oil life is low, the
CHANGE ENGINE OIL SOON message will
appear on the display. The oil should be
changed as soon as possible. See Engine Oil
0 305. In addition to the engine oil life
system monitoring the oil life, additional
maintenance is recommended. See
Maintenance Schedule 0384.
The Oil Life display must be reset after each
oil change. It will not reset itself. Do not
reset the Oil Life display at any time other
than when the oil has just been changed. It cannot be reset accurately until the next
oil change. To reset, see
Engine Oil Life
System 0307.
Air Filter Life
Turn the trip odometer reset stem until AIR
FILTER LIFE displays. This displays an
estimate of the engine air filter’s remaining
useful life and the state of the system.
Engine Air Filter Life 95% means 95% of the
current air filter life remains. Messages will
display based on the engine air filter life
and the state of the system.
When the REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the time of the next
oil change. When the REPLACE SOON
message displays, the engine air filter
should be replaced at the earliest
convenience.
The Air Filter Life display must be reset after
the engine air filter replacement. To reset,
see Engine Air Filter Life System 0308.
Brake Pad Life
This displays an estimate of the remaining
life of the front and rear brake pads.
Messages will display based on brake pad
wear and the state of the system. Reset the Brake Pad Life display after replacing the
brake pads. See
Brake Pad Life System
0 316.
Driver Information Center (DIC)
(Midlevel and Uplevel)
The DIC displays are shown in the center of
the instrument cluster in the Info app. See
Instrument Cluster 0102. The displays show
the status of many vehicle systems.
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
SorT: Press to move left or right
between the interactive display zones in the
cluster. Press the thumbwheel to select.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
122 Instruments and Controls
When the remaining oil life is low, the
CHANGE ENGINE OIL SOON message will
appear on the display. The oil should be
changed as soon as possible. SeeEngine Oil
0 305. In addition to the engine oil life
system monitoring the oil life, additional
maintenance is recommended. See
Maintenance Schedule 0384.
The Oil Life display must be reset after each
oil change. It will not reset itself. Do not
reset the Oil Life display at any time other
than when the oil has just been changed.
It cannot be reset accurately until the next
oil change. To reset, see Engine Oil Life
System 0307.
Tire Pressure : Shows the approximate
pressures of all four tires. Tire pressure is
displayed in either kilopascal (kPa) or in
pounds per square inch (psi). If the pressure
is low, the value for that tire is shown in
amber. See Tire Pressure Monitor System
0 342 and
Tire Pressure Monitor Operation 0343.
Air Filter Life : Shows an estimate of the
engine air filter’s remaining useful life and
the state of the system. Engine Air Filter Life
95% means 95% of the current air filter life
remains. Messages will display based on the
engine air filter life and the state of the system. When the REPLACE AT NEXT OIL
CHANGE message displays, the engine air
filter should be replaced at the time of the
next oil change. When the REPLACE SOON
message displays, the engine air filter
should be replaced at the earliest
convenience.
The Air Filter Life display must be reset after
the engine air filter replacement. To reset,
see
Engine Air Filter Life System 0308.
Brake Pad Life : This displays an estimate of
the remaining life of the front and rear
brake pads. Messages will display based on
brake pad wear and the state of the system.
Reset the Brake Pad Life display after
replacing the brake pads. See Brake Pad Life
System 0316.
Fuel Economy : Displays average fuel
economy, the best fuel economy over the
selected distance, and a bar graph showing
instantaneous fuel economy.
Press the thumbwheel to change the
selected distance. Press and hold the
thumbwheel while this display is active to
reset the best fuel economy and average
fuel economy. This display can also be reset
by selecting reset in the menu. Engine Hours (Hourmeter) :
Shows the total
number of hours the engine has run. This
display also shows the engine idle hours.
Transmission Fluid Temperature : Shows the
temperature of the automatic transmission
fluid in either degrees Celsius (°C) or degrees
Fahrenheit (°F).
Trailer Brake : On vehicles with the
Integrated Trailer Brake Control (ITBC)
system, the trailer brake display appears in
the DIC.
TRAILER GAIN shows the trailer gain setting.
This setting can be adjusted from 0.0 to 10.0
with either a trailer connected or
disconnected.
TRAILER OUTPUT shows the power output to
the trailer any time a trailer with electric
brakes is connected. Output is displayed as a
bar graph. Dotted lines may appear in the
OUTPUT display if a trailer is not connected.
Off Road : Displays vehicle pitch and roll
information, road wheel angle, and
four-wheel drive (4WD) status.
Follow Distance : If equipped, the current
follow time to the vehicle ahead is displayed
as a time value on this page.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Climate Controls 199
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . . . . . . . . . . 199
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Maintenance
Passenger Compartment Air Filter . . . . . 204
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Climate Control Systems
The heating, cooling, and ventilation in the vehicle can be controlled with this system.
1. Fan Control
2. MAX Defrost
3. Air Delivery Mode Controls
4. A/C (Air Conditioning)
5. TEMP (Temperature Control)
6. Recirculation
7. Rear Window Defogger (If Equipped) or Heated Mirrors (If Equipped)9:Turn clockwise or counterclockwise to
increase or decrease the fan speed. Turn the
knob all the way counterclockwise to turn
the fan off.
TEMP : Turn clockwise or counterclockwise
to increase or decrease the temperature
inside the vehicle.