
Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
388 Service and Maintenance
Footnotes—Maintenance Schedule
Additional Required Services - Normal
(1) Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 309.
(2) Or every two years, whichever comes
first. More frequent replacement may be
needed if the vehicle is driven in areas with
heavy traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter replacement
may also be needed if you notice reduced
airflow, windows fogging up, or odors. Your
local GM Service location can help you
determine when it is the right time to
replace your filter.
(3) Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition. (4)
Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced.
(5) Or every five years, whichever comes
first. See Cooling System 0310.
(6) Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed.
(7) Replace brake fluid every five years. See
Brake Fluid 0317.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0322.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0323.
(10) Replace air conditioning desiccant every
seven years.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Service and Maintenance 389
Maintenance Schedule Additional
Required Services - Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or boots.@
Change automatic transmission fluid and filter.@@@
Change transfer case fluid, if equipped with 4WD. (4)@@@@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate dampener. (9)@ @
Replace air conditioning desiccant. (10)

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
390 Service and Maintenance
Footnotes—Maintenance Schedule
Additional Required Services - Severe
(1) Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 309.
(2) Or every two years, whichever comes
first. More frequent replacement may be
needed if the vehicle is driven in areas with
heavy traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter replacement
may also be needed if you notice reduced
airflow, windows fogging up, or odors. Your
local GM Service location can help you
determine when it is the right time to
replace your filter.
(3) Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition.
(4) Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced. (5)
Or every five years, whichever comes
first. See Cooling System 0310.
(6) Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed.
(7) Replace brake fluid every five years. See
Brake Fluid 0317.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0322.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0323.
(10) Replace air conditioning desiccant every
seven years.
Special Application Services
.Vehicles with Dual Wheels: Check dual
wheel nut torque at 160, 1 600, and
10 000 km (100, 1,000, and 6,000 mi) of
driving. Repeat this service whenever a
tire/wheel is serviced or removed.
.Severe Commercial Use Vehicles Only:
Lubricate chassis components every oil
change.
.Have underbody flushing service
performed. See “Underbody Maintenance”
in Exterior Care 0373.
Additional Maintenance
and Care
Your vehicle is an important investment and
caring for it properly may help to avoid
future costly repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer perform
these services —their trained dealer
technicians know your vehicle best. Your
dealer can also perform a thorough
assessment with a multi-point inspection to
recommend when your vehicle may need
attention.
The following list is intended to explain the
services and conditions to look for that may
indicate services are required.
Battery
The 12-volt battery supplies power to start
the engine and operate any additional
electrical accessories.
.To avoid break-down or failure to start
the vehicle, maintain a battery with full
cranking power.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
394 Service and Maintenance
UsageFluid/Lubricant
Key Lock Cylinders, Hood Hinges, Body Door Hinge Pins, Tailgate Hinge and Linkage, Fuel Door Hinge, Tailgate Handle Pivot Points, Hinges, Latch Bolt, and Linkage Multi-Purpose Lubricant, Superlube. See your dealer.
Transfer Case (Four-Wheel Drive) DEXRON-VI Automatic Transmission Fluid. Windshield Washer Automotive windshield washer fluid that meets regional freeze protection requirements.
Maintenance Replacement Parts
Replacement parts identified below by name, part number, or specification can be obtained from your dealer.
If the vehicle has a diesel engine, see the Duramax diesel supplement.
Part GM Part Number ACDelco Part Number
Engine Air Cleaner/Filter
IWith high capacity air cleaner 84121219 A3244C
IWithout high capacity air cleaner 84121217 A3246C
Oil Filter 12690385 PF63E
Passenger Compartment Air Filter 13508023 CF185
Spark Plugs 12622441 41-114

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
398 Technical Data
Vehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and Lubricants0393.
If the vehicle has a diesel engine, see the Duramax diesel supplement.
Application Capacities
Metric English
Air Conditioning Refrigerant For the air conditioning system refrigerant type and charge amount, see the refrigerant label under the hood. See yourdealer for more information.
Engine Cooling System* 14.6 L 15.4 qt
Engine Oil with Filter 7.6 L 8.0 qt
Fuel Tank
I2500 Series and 3500 Series Standard Box (Except Double Cab Diesel) 136.3 L 36.0 gal
I2500 Series and 3500 Series Standard Box (Double Cab Diesel) 111.3 L 29.4 gal
I2500 Series and 3500 Series Long Box (Except Regular Cab Diesel) 136.3 L 36.0 gal
I2500 Series and 3500 Series Long Box (Regular Cab Diesel) 106.0 L 28.0 gal

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
420 Index
IndexA
Accessories and Modifications . . . . . . . . . . . 302
Accessory Power . . . . . . . . . . . . . . . . . . . . . . . . . 229
Add-On Electrical Equipment . . . . . . . . . . . . . 297
Adding a Snow Plow or SimilarEquipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Additional Information OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Additional Maintenance and Care . . . . . . . . 390
Adjustments Lumbar, Front Seats . . . . . . . . . . . . . . . . . . . . 45
Agreements Trademarks and License . . . . . . . . . . . . . . . 190
Air Cleaner/Filter, Engine . . . . . . . . . . . . . . . . 309
Air Conditioning . . . . . . . . . . . . . . . . . . . . .199, 201
Air Filter
Life System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Air Filter, Passenger Compartment . . . . . . . 204
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
How Does an Airbag Restrain? . . . . . . . . . . 61
Passenger Sensing System . . . . . . . . . . . . . . 62
What Makes an Airbag Inflate? . . . . . . . . . 61
What Will You See after an AirbagInflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
When Should an Airbag Inflate? . . . . . . . . 60
Where Are the Airbags? . . . . . . . . . . . . . . . . 59 Airbags
Adding Equipment to the Vehicle . . . . . . . 66
Passenger Status Indicator . . . . . . . . . . . . . 110
Readiness Light . . . . . . . . . . . . . . . . . . . . . . . . 110
Servicing Airbag-Equipped Vehicles . . . . . . 66
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Alarm
Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . 27
Alert Lane Change . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Side Blind Zone (SBZA) . . . . . . . . . . . . . . . . . 260
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 337
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 337
AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Antenna Fixed Mast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Multi-band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Antilock Brake System (ABS) . . . . . . . . . . . . . 240 Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
Apple CarPlay and Android Auto . . . . . . . . . 180
Assistance Program, Roadside . . . . . . . . . . . . 404
Assistance Systems for Driving . . . . . . . . . . 257
Assistance Systems for Parking and Backing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Index 423
Driver Mode Control Light . . . . . . . . . . . . . . . . 117
DrivingAssistance Systems . . . . . . . . . . . . . . . . . . . . 257
Better Fuel Economy . . . . . . . . . . . . . . . . . . . 207
Characteristics and Towing Tips . . . . . . . . 268
Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Hill and Mountain Roads . . . . . . . . . . . . . . 215
If the Vehicle is Stuck . . . . . . . . . . . . . . . . . 216
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 210
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 210
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . . 217
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Dual Automatic Climate Control
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
E
E85 or FlexFuel . . . . . . . . . . . . . . . . . . . . . . . . . . 264
Electric Parking Brake . . . . . . . . . . . . . . . . . . . . 240
Electric Parking Brake Light . . . . . . . . . . . . . . . 113
Electrical Equipment, Add-On . . . . . . . . . . . . 297
Electrical SystemEngine Compartment Fuse Block . . . . . . . 329
Fuses and Circuit Breakers . . . . . . . . . . . . . 329
Instrument Panel Fuse Block . . . . . . 332, 334
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 Electronic Stability Control (ESC) Off
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . 309
Check Light (Malfunction Indicator) . . . . . 111
Compartment Overview . . . . . . . . . . . . . . . . 304
Coolant Temperature Gauge . . . . . . . . . . . 108
Coolant Temperature Warning Light . . . . 116
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 310
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . 400
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 307
Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . 107
Oil Pressure Light . . . . . . . . . . . . . . . . . . . . . . . 117
Overheated ProtectionOperating Mode . . . . . . . . . . . . . . . . . . . . . 314
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
Power Messages . . . . . . . . . . . . . . . . . . . . . . . 126
Running While Parked . . . . . . . . . . . . . . . . . 232
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Engine Air Filter Life System . . . . . . . . . . . . . 308
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Equipment, Towing . . . . . . . . . . . . . . . . . . . . . . 276
Event Data Recorders . . . . . . . . . . . . . . . . . . . . . 411 Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Extended Parking . . . . . . . . . . . . . . . . . . . . . . . . . 231
Extender, Seat Belt . . . . . . . . . . . . . . . . . . . . . . . 56
Exterior Cargo Lamps . . . . . . . . . . . . . . . . . . . . 139
Exterior Lamp Controls . . . . . . . . . . . . . . . . . . . .134
Exterior Lamps Off Reminder . . . . . . . . . . . . 136
Exterior Lighting Battery Saver . . . . . . . . . . .142
F
Fan
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Filter,
Engine Air Cleaner . . . . . . . . . . . . . . . . . . . . . 309
Fixed Mast Antenna . . . . . . . . . . . . . . . . . . . . . . 153
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Flashers, Hazard Warning . . . . . . . . . . . . . . . . . 137
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
Floor Console Storage . . . . . . . . . . . . . . . . . . . . . 93
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .381
Fluid
Automatic Transmission . . . . . . . . . . . . . . . 308
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Four-Wheel Drive Transfer Case . . . . . . . . 236
Power Steering . . . . . . . . . . . . . . . . . . . . . . . . 314
Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Index 427
Off-Road (cont'd)Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
Engine Oil Life System . . . . . . . . . . . . . . . . . 307
Engine Oil Pressure Gauge . . . . . . . . . . . . . 107
Pressure Light . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Older Children, Restraints . . . . . . . . . . . . . . . . . 68
Online Owner Center . . . . . . . . . . . . . . . . . . . . 403
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
OnStar Additional Information . . . . . . . . . . . .413
OnStar Emergency . . . . . . . . . . . . . . . . . . . . . . . .413
OnStar Overview . . . . . . . . . . . . . . . . . . . . . . . . . .412
OnStar Security . . . . . . . . . . . . . . . . . . . . . . . . . . .413
OnStar System . . . . . . . . . . . . . . . . . . . . . . 157, 168
Operating Mode Overheated Engine Protection . . . . . . . . . 314
Operation Fog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . . . .314
Overheating, Engine . . . . . . . . . . . . . . . . . . . . . . 312
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Instrument Panel . . . . . . . . . . . . . . . . . . . . . . . . 4P
Park
Shifting Into . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Shifting Out of . . . . . . . . . . . . . . . . . . . . . . . . 231
Park Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Parking
Brake and P (Park) MechanismCheck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Extended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
Over Things That Burn . . . . . . . . . . . . . . . . . 231
Parking or Backing Assistance Systems . . . . . . . . . . . . . . . . . . . . 249
Passenger Airbag Status Indicator . . . . . . . . .110
Passenger Compartment Air Filter . . . . . . . 204
Passenger Sensing System . . . . . . . . . . . . . . . . 62
Perchlorate Materials Requirements, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
Personalization Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Phone Apple CarPlay and Android Auto . . . . . . . 180
Bluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . 175, 176
Pickup Conversion to Chassis Cab . . . . . . . . 299
Port USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Positioning Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Power
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Protection, Battery . . . . . . . . . . . . . . . . . . . . . 142
Retained Accessory (RAP) . . . . . . . . . . . . . . 229
Seat Adjustment . . . . . . . . . . . . . . . . . . . . . . . . 44
Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Power Assist Steps . . . . . . . . . . . . . . . . . . . . . . . . 26
Pregnancy, Using Seat Belts . . . . . . . . . . . . . . 56
Privacy Vehicle Data Recording . . . . . . . . . . . . . . . . 410
Problems with Route Guidance . . . . . . . . . . 169
Program Courtesy Transportation . . . . . . . . . . . . . . . 406
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . . . 264
Proposition 65 Warning, California . . . . . . . . . . . . . . . . . . . . .301, 318, 367, Back Cover
Publication Ordering Information . . . . . . . . 408
R
Radio
HD Radio Technology . . . . . . . . . . . . . . . . . . . 151
Radio Data System (RDS) . . . . . . . . . . . . . . . . . 152
Radio Frequency Statement . . . . . . . . . . . . . . 409
Radio Reception . . . . . . . . . . . . . . . . . . . . . . . . . . 153