2021 CHEVROLET SILVERADO 2500HD lane assist

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Driving and Operating 269
.State laws may require the use of
extended side view mirrors. Even if not
required, you should install extended side
view mirrors if your visibility is limited or
restricted while towing.
.Do not tow a trailer during the first
800 km (500 mi) of vehicle use to prevent
damage to the engine, axle, or other
parts.
.It is recommended to perform the first oil
change before heavy towing.
.During the first 800 km (500 mi) of trailer
towing, do not drive over 80 km/h
(50 mph) and do not make starts at full
throttle.
.Vehicles can tow in D (Drive). Tow/Haul
Mode is recommended for heavier trailers.
SeeTow/Haul Mode 0235. If the
transmission downshifts too often, a
lower gear may be selected using Manual
Mode. See Manual Mode 0235.
If equipped, the following driver assistance
features should be turned off when towing
a trailer:
.Adaptive Cruise Control (ACC)
.Super Cruise Control
.Lane Keep Assist (LKA)
.Park Assist
.Automatic Parking Assist (APA)
.Reverse Automatic Braking (RAB)
If equipped, the following driver assistance
features should be turned to alert or off
when towing a trailer:
.Automatic Emergency Braking (AEB)
.Intelligent Brake Assist (IBA)
.Front Pedestrian Braking (FPB)
If equipped with Lane Change Alert (LCA),
the LCA detection zones that extend back
from the side of the vehicle do not move
further back when a trailer is towed. Use
caution while changing lanes when towing a
trailer.
If equipped with Rear Cross Traffic Alert
(RCTA), use caution while backing up when
towing a trailer, as the RCTA detection zones
that extend out from the back of the vehicle
do not move further back when a trailer is
towed.
{Warning
To prevent serious injury or death from
carbon monoxide (CO), when towing a
trailer: (Continued)
Warning (Continued)
.Do not drive with the liftgate, trunk/
hatch, or rear-most window open.
.Fully open the air outlets on or under
the instrument panel.
.Adjust the climate control system to a
setting that brings in only outside air.
See“Climate Control Systems” in the
Index.
For more information about carbon
monoxide, see Engine Exhaust 0232.
Towing a trailer requires experience. The
combination of the vehicle and trailer is
longer and not as responsive as the vehicle
itself. Get used to the handling and braking
of the combination by driving on a level
road surface before driving on public roads.
The trailer structure, the tires, and the
brakes must all be rated to carry the
intended cargo. Inadequate trailer
equipment can cause the combination to
operate in an unexpected or unsafe manner.
Before driving, inspect all trailer hitch parts
and attachments, safety chains, electrical
connectors, lamps, tires, and mirrors. See
Towing Equipment 0276. If the trailer has
electric brakes, start the combination

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
270 Driving and Operating
moving and then manually apply the trailer
brake controller to check that the trailer
brakes work. During the trip, occasionally
check that the cargo and trailer are secure
and that the lamps and any trailer brakes
are working.
Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel with
one hand. To move the trailer to the left,
move that hand to the left. To move the
trailer to the right, move that hand to the
right. Always back up slowly and, if possible,
have someone guide you.
Making TurnsCaution
Turn more slowly and make wider arcs
when towing a trailer to prevent damage
to your vehicle. Making very sharp turns
could cause the trailer to contact the
vehicle.
Make wider turns than normal when towing,
so the trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency. The vehicle can tow in D (Drive). Shift the
transmission to a lower gear if the
transmission shifts too often under heavy
loads and/or hilly conditions.
When towing at higher altitudes, engine
coolant will boil at a lower temperature
than at lower altitudes. If the engine is
turned off immediately after towing at high
altitude on steep uphill grades, the vehicle
could show signs similar to engine
overheating. To avoid this, let the engine
run, preferably on level ground, with the
transmission in P (Park) for a few minutes
before turning the engine off. If the
overheat warning comes on, see
Engine
Overheating 0312.
Viewing Systems
If equipped, the viewing systems on the
vehicle can improve visibility while hitching,
backing, and driving with a trailer. See
Driver Assistance Systems 0247.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Driving and Operating 281
Camper/Fifth-Wheel Trailer Wiring Package
For vehicles without the fifth wheel/
gooseneck trailer package, the seven-wire
camper harness is under the rear bumper,
attached to the frame near the rear
crossmember. A connector must be added to
the wiring harness that connects to the
camper.
The harness contains the following camper/
trailer circuits:Stop/Turn
Signal Left Yellow/Blue
Stop/Turn Signal
Right Green/Violet
Tail/Parking Lamps Gray/Brown Reverse Lamps White/Green
Battery Feed Red/Green
Ground White
Electric Trailer Brake Blue
If equipped with the heavy-duty trailering
option, see “Heavy-Duty Trailer Wiring
Harness Package” earlier in this section.
When the camper-wiring harness is ordered
without the heavy-duty trailering package, a
seven-wire harness with a seven-pin
connector is at the rear of the vehicle and is
tied to the vehicle's frame.
Trailer Lamps
Always check that all trailer lamps are
working at the beginning of each trip, and
periodically on longer trips.
If equipped, the Trailering App will monitor
the RH turn/brake lamp circuit, LH turn/
brake lamp circuit, running lamp circuit, and
reverse lamp circuits on the trailer. DIC
messages and Trailering App alerts may be
displayed if lighting circuit issues are
detected on the trailer. Pressing START LIGHT TEST in the Trailering
App automatically activates the trailer
lamps. The Trailering App is not a substitute
for manually inspecting your trailer lamps.
See
Trailering App 0286.
Turn Signals When Towing a Trailer
When properly connected, the trailer turn
signals will illuminate to indicate the vehicle
is turning, changing lanes, or stopping.
When towing a trailer, the arrows on the
instrument cluster will illuminate even if the
trailer is not properly connected or the bulbs
are burned out.
Tow/Haul Mode
For instructions on how to enter Tow/Haul
Mode, see Driver Mode Control 0244.
Tow/Haul assists when pulling a heavy
trailer or a large or heavy load. See Tow/
Haul Mode 0235.
Tow/Haul Mode is designed to be most
effective when the vehicle and trailer
combined weight is at least 75% of the
vehicle's Gross Combined Weight Rating
(GCWR). See “Trailer Weight” underTrailer
Towing 0272.

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 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
Index 429
Seats (cont'd)Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . 45
Underseat Storage . . . . . . . . . . . . . . . . . . . . . . 92
Securing Child Restraints . . . . . . . . . . . . . . 84, 87
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Vehicle Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 Accessories and Modifications . . . . . . . . . 302
Climate Control System . . . . . . . . . . . . . . . . 199
Doing Your Own Work . . . . . . . . . . . . . . . . . 302
Maintenance Records . . . . . . . . . . . . . . . . . . 396
Maintenance, General Information . . . . . 383
Parts Identification . . . . . . . . . . . . . . . . . . . . . 397
Scheduling Appointments . . . . . . . . . . . . . . 405
Service Electric Parking Brake Light . . . . . . . 113
Services Special Application . . . . . . . . . . . . . . . . . . . . . 390
Servicing System . . . . . . . . . . . . . . . . . . . . . . . . 170
Servicing the Airbag . . . . . . . . . . . . . . . . . . . . . . 66
Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Shift Lock Control Function Check, Automatic Transmission . . . . . . . . . . . . . . . . 322
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 Shifting (cont'd)
Out of Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
Side Blind Zone Alert (SBZA) . . . . . . . . . . . . . 260
Signals, Turn and Lane-Change . . . . . . . . . . . .138
Snow Plow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Software Updates . . . . . . . . . . . . . . . . . . . . . . . . 150
Special Application Services . . . . . . . . . . . . . . 390
Specifications and Capacities . . . . . . . . . . . . . 398
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Start Assist, Hill . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Start Vehicle, Remote . . . . . . . . . . . . . . . . . . . . . 20
Starter Switch Check . . . . . . . . . . . . . . . . . . . . . . 321
Starting the Engine . . . . . . . . . . . . . . . . . . . . . . 227
Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 Fluid, Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Heated Wheel . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Wheel Adjustment . . . . . . . . . . . . . . . . . . . . . . 96
Wheel Controls . . . . . . . . . . . . . . . . . . . . . . . . . 96
Steering Column Lock . . . . . . . . . . . . . . . . . . . . . 28
Steering Wheel Controls . . . . . . . . . . . . . . . . . 146
Steps Power Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Stoplamps and Back-up Lamps Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . 326
Storage Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Storage Areas Center Console . . . . . . . . . . . . . . . . . . . . . . . . . 92 Storage Areas (cont'd)
Floor Console . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Glove Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Underseat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Storage Compartments . . . . . . . . . . . . . . . . . . . .91
Struts Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Stuck Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Sun Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
System Brake Pad Life . . . . . . . . . . . . . . . . . . . . . . . . . 316
Engine Air Filter Life . . . . . . . . . . . . . . . . . . . 308
Forward Collision Alert (FCA) . . . . . . . . . . . 257
Global Positioning . . . . . . . . . . . . . . . . . . . . . 168
Infotainment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Noise Control . . . . . . . . . . . . . . . . . . . . . . . . . . 320
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Systems
Driver Assistance . . . . . . . . . . . . . . . . . . . . . . 247
T
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23