2021 CHEVROLET SILVERADO 2500HD key

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
372 Vehicle Care
the transmission to D (Drive) and then to
R (Reverse). There should be no
movement while shifting the
transmission.
6. Shift the transmission to D (Drive).
7. If equipped with an ignition key, turn the ignition to ACC/ACCESSORY.
If equipped with Keyless Access, turn the
engine off. Disregard the Shift to P (Park)
DIC message. See Ignition Positions
(Keyless Access) 0226 or
Ignition Positions (Key Access) 0224.
{Warning
To avoid death, serious injury,
or property damage, before dinghy
towing the vehicle, always disconnect and
secure the negative battery cable and
cover the negative battery post and cable
with a non-conductive material. If the
battery is left connected or the battery
cable contacts the post, the Electric
Parking Brake may activate during
towing, which could cause a crash.
8. Disconnect the negative (–) battery cable. See “Negative Battery Cable
Disconnection” inBattery - North
America 0318. 9. Shift the transmission to P (Park).
Caution
If the steering column is locked, vehicle
damage may occur.
10. Move the steering wheel to make sure the steering column is unlocked.
11. If the vehicle has an ignition key, keep it in the towed vehicle in ACC/ACCESSORY
to prevent the steering column from
locking. If the vehicle is equipped with
Keyless Access, keep the RKE transmitter
outside of the vehicle and manually lock
the doors. Access the vehicle by using
the key in the door lock. See Door Locks
0 21.
Disconnecting the Towed Vehicle
Before disconnecting from the tow vehicle: 1. Park on a level surface. Secure the vehicle with wheel blocks.
2. Re-connect the negative (–) battery. See Battery - North America 0318.
3. Turn on the ignition with the engine off. For vehicles with a key, turn the ignition
to ON/RUN with the engine off. If the
vehicle is equipped with Keyless Access,
with your foot off the brake pedal, press and hold ENGINE START/STOP for
five seconds until the green light comes
on in the button. See
Ignition Positions
(Keyless Access) 0226 or
Ignition Positions (Key Access) 0224.
4. Set the parking brake. See Electric
Parking Brake 0240.
5. Disconnect from the tow vehicle.
6. Shift the transmission to N (Neutral).
7. Shift the transfer case to 2
m(Two-Wheel
Drive High). When the shift to 2
m
(Two-Wheel Drive High) is complete, the
light in the instrument cluster will stop
flashing and stay lit. See
Four-Wheel-Drive Light 0114.
8. Start the engine. Check that the vehicle is in 2
m(Two-Wheel Drive High) by
starting the engine and shifting the
transmission to D (Drive) and then to
R (Reverse). There should be movement
of the vehicle while shifting.
9. Shift the transmission to P (Park) and turn off the ignition.
10. Release the parking brake and remove the wheel blocks.
11. Reset any lost presets.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
378 Vehicle Care
Visually check constant velocity joint boots
and axle seals for leaks.
2500/3500 Series vehicles, at least every
engine oil change lubricate the upper and
lower control arm ball joints.
2500/3500 Series vehicles equipped with
steering linkage, at least every engine oil
change lubricate the tie rod ball joints, idler
arm pivot shaft bearings, idler arm socket,
and pitman arm socket.
Caution
Lubrication of applicable suspension
points should not be done unless the
temperature is−12 °C (10 °F) or higher,
or damage could result.
Body Component Lubrication
Lubricate all key lock cylinders, hood hinges,
liftgate hinges, and the steel fuel door hinge
unless the components are plastic. Applying
silicone grease on weatherstrips with a clean
cloth will make them last longer, seal better,
and not stick or squeak.
Underbody Maintenance
At least twice a year, spring and fall, use
plain water to flush any corrosive materials
from the underbody. Take care to
thoroughly clean any areas where mud and
other debris can collect. If equipped with
power assist steps, extend them and then
use a high pressure wash to clean all joints
and gaps.
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 axles and should be replaced.
Sheet Metal Damage
If the vehicle is damaged and requires sheet
metal repair or replacement, make sure the
body repair shop applies anti-corrosion
material to parts repaired or replaced to
restore corrosion protection.
Original manufacturer replacement parts will
provide the corrosion protection while
maintaining the vehicle warranty.
Finish Damage
Quickly repair minor chips and scratches
with touch-up materials available from your
dealer to avoid corrosion. Larger areas of
finish damage can be corrected in your
dealer's body and paint shop.
Chemical Paint Spotting
Airborne pollutants can fall upon and attack
painted vehicle surfaces causing blotchy,
ring-shaped discolorations, and small,
irregular dark spots etched into the paint
surface. Refer to “Finish Care”previously in
this section.
Interior Care
To prevent dirt particle abrasions, regularly
clean the vehicle's interior. Immediately
remove any soils. Newspapers or dark
garments can transfer color to the vehicle’s
interior.
Use a soft bristle brush to remove dust from
knobs and crevices on the instrument
cluster. Using a mild soap solution,
immediately remove hand lotions,
sunscreen, and insect repellent from all
interior surfaces or permanent damage may
result.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
386 Service and Maintenance
.Check restraint system components. See
Safety System Check056.
.Visually inspect fuel system for damage
or leaks.
.Visually inspect exhaust system and
nearby heat shields for loose or damaged
parts.
.Lubricate body components. See Exterior
Care 0373.
.Check starter switch. See Starter Switch
Check 0321.
.Check automatic transmission shift lock
control function. See Automatic
Transmission Shift Lock Control Function
Check 0322.
.Check ignition transmission lock. See
Ignition Transmission Lock Check 0322.
.Check parking brake and automatic
transmission park mechanism. See Park
Brake and P (Park) Mechanism Check
0 322.
.Check accelerator pedal for damage, high
effort, or binding. Replace if needed.
.Visually inspect gas strut for signs of
wear, cracks, or other damage. Check the
hold open ability of the strut. If the hold
open is low, service the gas strut. See Gas
Strut(s) 0323.
.Inspect sunroof track and seal,
if equipped. See Sunroof040.
.Verify spare tire key lock operation and
lubricate as needed. See Tire Changing
0 356.
.Visually inspect the spare tire to ensure
that it is tightly stowed under the vehicle.
Push, pull, and try to turn the tire. If the
spare tire moves, tighten as necessary.
See Tire Changing 0356.

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
OnStar 413
.Receive a Diagnostic check of the vehicle's
key operating systems.
.Receive Roadside Assistance.
.Manage Wi-Fi Settings, if equipped.
Press
>to get a priority connection to an
OnStar Advisor available 24/7 to:
.Get help for an emergency.
.Be a Good Samaritan or respond to an
AMBER Alert.
.Get assistance in severe weather or other
crisis situations and find evacuation
routes.
OnStar Services
Emergency
Emergency Services require an active safety
and security plan. With Automatic Crash
Response, built-in sensors can automatically
alert a specially trained OnStar Advisor who
is immediately connected in to the vehicle
to help.
Press
>for a priority connection to an
OnStar Advisor who can contact emergency
service providers, direct them to your exact
location, and relay important information. With OnStar Crisis Assist, specially trained
Advisors are available 24 hours a day, 7 days
a week, to provide a central point of
contact, assistance, and information during a
crisis.
With Roadside Assistance, Advisors can
locate a nearby service provider to help with
a flat tire, a battery jump, or an empty
gas tank.
Security
If equipped, OnStar provides these services:
.With Stolen Vehicle Assistance, OnStar
Advisors can use GPS to pinpoint the
vehicle and help authorities quickly
recover it.
.With Remote Ignition Block, if equipped,
OnStar can block the engine from being
restarted.
.With Stolen Vehicle Slowdown,
if equipped, OnStar can work with law
enforcement to gradually slow the
vehicle down.
Theft Alarm Notification
If equipped, if the doors are locked and the
vehicle alarm sounds, a notification by text,
e-mail, or phone call will be sent. If the
vehicle is stolen, an OnStar Advisor can work
with authorities to recover the vehicle.
OnStar Additional
Information
In-Vehicle Audio Messages
Audio messages may play important
information at the following times:
.Prior to vehicle purchase. PressQto
set up an account.
.After change in ownership and at
90 days.
Transferring Service
PressQto request account transfer
eligibility information. The Advisor can
cancel or change account information.
Selling/Transferring the Vehicle
Call 1-888-4ONSTAR (1-888-466-7827)
immediately to terminate your OnStar or
connected services if the vehicle is disposed
of, sold, transferred, or if the lease ends.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Connected Services 419
.Request Roadside Assistance.
.Set a parking reminder with pin drop,
take a photo, make a note, and set a
timer.
.Connect with Chevrolet on social media.
Features are subject to change. For
myChevrolet mobile app information and
compatibility, see my.chevrolet.com.
An active OnStar or connected service plan
may be required. A compatible device,
factory-installed remote start, and power
locks are required. Data rates apply. See
www.onstar.com for details and system
limitations.
Remote Services
Contact an OnStar Advisor to unlock the
doors or sound the horn and flash the
lamps.
Marketplace
OnStar Advisors can provide offers from
restaurants and retailers on your route, help
locate hotels, or book a room. These services
vary by market.
Diagnostics
By monitoring and reporting on the vehicle's
key systems, OnStar Advanced Diagnostics,
if equipped, provides a way to keep up on
maintenance. Capabilities vary by model.
See www.onstar.com for details and system
limitations. Features are subject to change.
For updates on feature capabilities, see
my.chevrolet.com. Message and data rates
may apply.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Index 425
Hill Descent Control Light . . . . . . . . . . . . . . . . . 114
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . . . . 242
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
How to Wear Seat Belts Properly . . . . . . . . . .52
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199, 201
I
If the System Needs Service . . . . . . . . . . . . . 170
Ignition Positions . . . . . . . . . . . . . . . . . . . 224, 226
Ignition Transmission Lock Check . . . . . . . . 322
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
IndicatorVehicle Ahead . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Infants and Young Children, Restraints . . . . 69
Information Publication Ordering . . . . . . . . . . . . . . . . . . . 408
Infotainment System . . . . . . . . . . . . . . . . . . . . . 411
Instrument Cluster . . . . . . . . . . . . . . . . . . . . . . . 102
Instrument Panel Overview . . . . . . . . . . . . . . . . 4
Interior Rearview Mirrors . . . . . . . . . . . . . . . . . 34
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 1, 143
J
Jack Auxiliary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Jump Starting - North America . . . . . . . . . . . 367
K
Keyless Entry
Remote (RKE) System . . . . . . . . . . . . . . . . 10, 13
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7, 9
L
Labeling, Tire Sidewall . . . . . . . . . . . . . . . . . . . 338
Lamps Auxiliary Roof Mounted Lamp . . . . . . . . . 139
Daytime Running (DRL) . . . . . . . . . . . . . . . . 136
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Exterior Cargo . . . . . . . . . . . . . . . . . . . . . . . . . 139
Exterior Controls . . . . . . . . . . . . . . . . . . . . . . . 134
Exterior Lamps Off Reminder . . . . . . . . . . 136
Exterior Lighting Battery Saver . . . . . . . . 142
License Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Malfunction Indicator (CheckEngine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
On Reminder . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Lane Change Alert (LCA) . . . . . . . . . . . . . . . . . 261
Lane Departure Warning (LDW) . . . . . . . . . . 262
Lane Departure Warning Light . . . . . . . . . . . . 115
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . . . 54
LATCH System Replacing Parts after a Crash . . . . . . . . . . . 84
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Lighting
Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Illumination Control . . . . . . . . . . . . . . . . . . . 140
LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Lights Airbag Readiness . . . . . . . . . . . . . . . . . . . . . . 110
Antilock Brake System (ABS)Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Brake System Warning . . . . . . . . . . . . . . . . . 113
Charging System . . . . . . . . . . . . . . . . . . . . . . . 111
Check Engine (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Door Ajar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Driver Mode Control . . . . . . . . . . . . . . . . . . . . 117
Electric Parking Brake . . . . . . . . . . . . . . . . . . . 113
Electronic Stability Control (ESC), Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Engine Coolant Temperature Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . . 117
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Four-Wheel-Drive . . . . . . . . . . . . . . . . . . . . . . . 114
Front Fog Lamp . . . . . . . . . . . . . . . . . . . . . . . . . 118
High-Beam On . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
428 Index
RadiosAM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Satellite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Reading Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Rear Camera Mirror . . . . . . . . . . . . . . . . . . . . . . . 34
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Heated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Rear Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Rear Vision Camera (RVC) . . . . . . . . . . . . . . . . 249
Rear Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Rearview Mirror Truck Bed Camera . . . . . . . . . . . . . . . . . . . . . . 37
Rearview Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 34 Automatic Dimming . . . . . . . . . . . . . . . . . . . . 34
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . . . 45
Recognition Voice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Recommended Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Recommended Fluids and Lubricants . . . . . 393
Records Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 396
Recreational Vehicle Towing . . . . . . . . . . . . . 370
Reimbursement Program, GM
Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404
Remote Keyless Entry (RKE) System . . . 10, 13 Remote Vehicle Start . . . . . . . . . . . . . . . . . . . . . 20
Replacement
Glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Replacement Parts Airbags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 394
Replacing Airbag System . . . . . . . . . . . . . . . . . . 67
Replacing LATCH System Parts after a
Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Replacing Seat Belt System Parts after a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Reporting Safety Defects Canadian Government . . . . . . . . . . . . . . . . . 409
General Motors . . . . . . . . . . . . . . . . . . . . . . . . 410
U.S. Government . . . . . . . . . . . . . . . . . . . . . . . 409
Restraints
Where to Put . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Retained Accessory Power (RAP) . . . . . . . . . 229
Reverse Tilt Mirrors . . . . . . . . . . . . . . . . . . . . . . . 34
Ride Control Systems Enhanced Traction System (ETS) . . . . . . . 245
Roads Driving, Wet . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Roadside Assistance Program . . . . . . . . . . . . 404
Roof Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Rotation, Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Routing, Engine Drive Belt . . . . . . . . . . . . . . .400 Running the Vehicle While Parked . . . . . . . 232
S
Safety Defects Reporting
Canadian Government . . . . . . . . . . . . . . . . . 409
General Motors . . . . . . . . . . . . . . . . . . . . . . . . 410
U.S. Government . . . . . . . . . . . . . . . . . . . . . . . 409
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Safety System Check . . . . . . . . . . . . . . . . . . . . . 56
Satellite Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Scheduling Appointments . . . . . . . . . . . . . . . . 405
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Extender . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
How to Wear Seat Belts Properly . . . . . . . 52
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . 54
Reminders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Replacing after a Crash . . . . . . . . . . . . . . . . . 57
Use During Pregnancy . . . . . . . . . . . . . . . . . . 56
Seats Adjustment, Front . . . . . . . . . . . . . . . . . . . . . . 43
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . 42
Heated and Ventilated Front . . . . . . . . . . . . 49
Heated, Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Lumbar Adjustment, Front . . . . . . . . . . . . . . 45
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Power Adjustment, Front . . . . . . . . . . . . . . . 44