check engine light CHEVROLET SILVERADO 2020 User Guide

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
282 Driving and Operating
{Warning
If a fire starts while you are
refueling, do not remove the fill
nozzle. Shut off the flow of fuel by
shutting off the pump or by
notifying the station attendant.
Leave the area immediately.
Caution
If a new fuel cap is needed, get
the right type of cap from your
dealer. The wrong type of fuel cap
may not fit properly, may turn on
the malfunction indicator lamp,
and could damage the fuel
system and emissions system.
SeeMalfunction Indicator Lamp
(Check Engine Light) 0135.
Filling a Portable Fuel
Container
{Warning
Never fill a portable fuel container
while it is in the vehicle. Static
electricity discharge from the
container can ignite the fuel
vapor. You or others could be
badly burned and the vehicle
could be damaged. To help avoid
injury to you and others:
. Dispense fuel only into
approved containers.
. Do not fill a container while
it is inside a vehicle, in a
vehicle's trunk, in a pickup
bed, or on any surface other
than the ground.
. Bring the fill nozzle in
contact with the inside of
the fill opening before
operating the nozzle.
Maintain contact until filling
is complete.
(Continued)
Warning (Continued)
.Keep sparks, flames, and
smoking materials away
from fuel.
. Do not use electronic
devices while pumping fuel.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
300 Driving and Operating
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. SeeTrailering App 0306.
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 0234.
Tow/Haul assists when pulling a
heavy trailer or a large or heavy
load. See Tow/Haul Mode 0223.
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 ”under Trailer
Towing 0288.
Tow/Haul Mode is most useful when
towing a heavy trailer or carrying a
large or heavy load:
. Through rolling terrain.
. In stop-and-go traffic.
. In busy parking lots.
Operating the vehicle in Tow/Haul
Mode when lightly loaded or not
towing will not cause damage;
however, it is not recommended and
may result in unpleasant engine and transmission driving characteristics,
heavy or light steering efforts, and
reduced fuel economy.
Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for use with electric trailer brakes or
most electric over hydraulic trailer
brake systems. These instructions
apply to both types of electric trailer
brakes.
This symbol is on the Trailer Brake
Control Panel on vehicles with an
ITBC system. The power output to
the trailer brakes is proportional to
the amount of vehicle braking. This
available power output to the trailer
brakes can be adjusted to a wide
range of trailering situations.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
304 Driving and Operating
4. If the CHECK TRAILERWIRING message reappears,
the electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING
message only reappears when
connecting the trailer wiring harness
to the vehicle, the electrical fault is
on the trailer side.
SERVICE TRAILER BRAKE
SYSTEM: This message will display
when there is a problem with the
ITBC system. If this message
continues over multiple ignition
cycles, have the vehicle serviced.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message displays
while driving, the ITBC system may
not be fully functional or may not
function at all. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service. A GM dealer may be able to
diagnose and repair problems with
the trailer. However, any diagnosis
and repair of the trailer is not
covered under the vehicle warranty.
Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.
Trailer Sway
Control (TSC)
Vehicles with StabiliTrak/Electronic
Stability Control (ESC) have a
Trailer Sway Control (TSC) feature.
Trailer sway is unintended
side-to-side motion of a trailer while
towing. If the vehicle is towing a
trailer and the TSC detects that
sway is increasing, the vehicle
brakes are selectively applied at
each wheel, to help reduce
excessive trailer sway. If equipped
with the Integrated Trailer Brake
Control (ITBC) system, and the
trailer has an electric brake system,
StabiliTrak/ESC may also apply the
trailer brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak/
ESC warning light will flash on the
instrument cluster. Reduce vehicle
speed by gradually removing your
foot from the accelerator. If trailer
sway continues, StabiliTrak/ESC
can reduce engine torque to help
slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned
off. See
Traction Control/Electronic
Stability Control 0231.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
318 Driving and Operating
This setting will default to OFF for
each Trailer Profile, including the
Guest Trailer Profile.
If Tow/Haul Mode is off and this
setting is on for a Trailer Profile,
each time the ignition is turned on a
reminder will appear to turn on Tow/
Haul Mode when the Trailer Profile
is active.
If Tow/Haul Mode is on and this
setting is on for a Trailer Profile, the
reminder will not appear when the
Trailer Profile is active.Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC)
is used for vehicle service and
Emission Inspection/
Maintenance testing. See
Malfunction Indicator Lamp
(Check Engine Light)0135.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 080 and
Adding Equipment to the
Airbag-Equipped Vehicle 080.
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
Vehicle Care 323
Vehicle Care
General Information
General Information . . . . . . . . . . 324
California Proposition65 Warning . . . . . . . . . . . . . . . . . 325
California Perchlorate Materials Requirements . . . . . 325
Accessories and Modifications . . . . . . . . . . . . . . . . 325
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 326
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 326
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 328
Engine Oil . . . . . . . . . . . . . . . . . . . . 335
Engine Oil Life System . . . . . . . 337
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 339
Engine Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . 339
Engine Air Cleaner/Filter . . . . . . 340
Cooling System . . . . . . . . . . . . . . 342
Engine Overheating . . . . . . . . . . 347
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 348
Engine Fan . . . . . . . . . . . . . . . . . . . 349 Power Steering Fluid . . . . . . . . . 350
Washer Fluid . . . . . . . . . . . . . . . . . 350
Brakes . . . . . . . . . . . . . . . . . . . . . . . 351
Brake Pad Life System . . . . . . . 352
Brake Fluid . . . . . . . . . . . . . . . . . . . 353
Battery - North America . . . . . . 354
Four-Wheel Drive . . . . . . . . . . . . . 356
Front Axle . . . . . . . . . . . . . . . . . . . . 357
Rear Axle . . . . . . . . . . . . . . . . . . . . 357
Noise Control System . . . . . . . . 357
Starter Switch Check . . . . . . . . . 358
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 359
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 359
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 359
Wiper Blade Replacement . . . . 360
Glass Replacement . . . . . . . . . . 361
Windshield Replacement . . . . . 361
Gas Strut(s) . . . . . . . . . . . . . . . . . . 361
Headlamp Aiming
Front Headlamp Aiming . . . . . . 362
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 362
Halogen Bulbs . . . . . . . . . . . . . . . . 362
LED Lighting . . . . . . . . . . . . . . . . . 363 Headlamps, Front Turn Signal,
Sidemarker, and Parking
Lamps . . . . . . . . . . . . . . . . . . . . . . 363
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 364
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 365
License Plate Lamp . . . . . . . . . . 366
Electrical System
Electrical System Overload . . . 366
Fuses and Circuit Breakers . . . 366
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 367
Instrument Panel Fuse
Block (Left) . . . . . . . . . . . . . . . . . 370
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 372
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 375
All-Season Tires . . . . . . . . . . . . . . 375
Winter Tires . . . . . . . . . . . . . . . . . . 376
Low-Profile Tires . . . . . . . . . . . . . 376
All-Terrain Tires . . . . . . . . . . . . . . . 377
Tire Sidewall Labeling . . . . . . . . 377
Tire Designations . . . . . . . . . . . . . 379
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 381

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
418 Vehicle Care
The positive (+) terminal is
under a red plastic cover at the
positive battery post. To
uncover the positive (+)
terminal, open the red plastic
cover.
For more information on the
location of the remote
positive (+) and remote
negative (−) terminals, see
Engine Compartment Overview
0328.
{Warning
An electric fan can start up even
when the engine is not running
and can injure you. Keep hands,
clothing, and tools away from any
underhood electric fan.
{Warning
Using a match near a battery can
cause battery gas to explode.
People have been hurt doing this,
(Continued)
Warning (Continued)
and some have been blinded.
Use a flashlight if you need more
light.
Battery fluid contains acid that
can burn you. Do not get it on
you. If you accidentally get it in
your eyes or on your skin, flush
the place with water and get
medical help immediately.
{Warning
Fans or other moving engine
parts can injure you badly. Keep
your hands away from moving
parts once the engine is running.
6. Check that the jumper cables do not have loose or missing
insulation. If they do, you could
get a shock. The vehicles
could be damaged too. Before you connect the cables,
here are some basic things you
should know. Positive (+) will
go to positive (+) or to a remote
positive (+) terminal if the
vehicle has one. Negative (−)
will go to a heavy, unpainted
metal engine part or to a
remote negative (−) terminal if
the vehicle has one.
Do not connect positive (+) to
negative (−) or you will get a
short that would damage the
battery and maybe other parts
too. And do not connect the
negative (−) cable to the
negative (−) terminal on the
dead battery because this can
cause sparks.
7. Connect one end of the red positive (+) cable to the remote
positive (+) terminal of the
vehicle with the discharged
battery.
8. Do not let the other end touch metal. Connect it to the
positive (+) terminal of the

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
Vehicle Care 423
11. If the vehicle has an ignitionkey, 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 026.
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 0354.
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) 0205 or
Ignition Positions (Key Access)
0 207.
4. Set the parking brake. See Electric Parking Brake 0229.
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
0 138.
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. The outside temperature
display will default to 0 °C
(32 °F) but will reset with
normal usage.
Dolly Towing

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
446 Service and Maintenance
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.
. Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts
. Belts may need replacing if they
squeak or show signs of
cracking or splitting.
. Trained dealer technicians have
access to tools and equipment
to inspect the belts and
recommend adjustment or
replacement when necessary.
Brakes
Brakes stop the vehicle and are
crucial to safe driving. .
Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
. Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle’s systems
and components. See
Recommended Fluids and
Lubricants 0448 for GM approved
fluids.
. Engine oil and windshield
washer fluid levels should be
checked at every fuel fill.
. Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled.
Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks. With a multi-point inspection, your
dealer can inspect the hoses and
advise if replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.
Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking.
. With a multi-point inspection,
your dealer can check the lamps
and note any concerns.
Shocks and Struts
Shocks and struts help aid in control
for a smoother ride.
. Signs of wear may include
steering wheel vibration, bounce/
sway while braking, longer
stopping distance, or uneven
tire wear.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
Index 481
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . . . 325
Accessory Power . . . . . . . . . . . . . . . 213
Active Fuel Management . . . . . . . 215
Adaptive Cruise Control . . . . . . . . 242
Add-On Electrical Equipment . . . 318
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . 319
Additional Information
OnStar . . . . . . . . . . . . . . . . . . . . . . . 474
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . . . 445
Adjustments
Lumbar, Front Seats . . . . . . . . . . . . 54
Air Cleaner/Filter, Engine . . . . . . . 340
Air Conditioning . . . . . . . . . . . 174, 176
Air Filter Life System . . . . . . . . . . . . . . . . . . . 339
Air Filter, Passenger Compartment . . . . . . . . . . . . . . . . . 180
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 179
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 81
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . . . 74
Passenger Sensing System . . . . 75 Airbag System (cont'd)
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 73
What Will You See after an Airbag Inflates? . . . . . . . . . . . . . . . 74
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 73
Where Are the Airbags? . . . . . . . . 71
Airbags Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . . . 80
Passenger Status Indicator . . . 133
Readiness Light . . . . . . . . . . . . . . 133
Servicing Airbag-Equipped
Vehicles . . . . . . . . . . . . . . . . . . . . . . . 80
System Check . . . . . . . . . . . . . . . . . . 69
Alarm Vehicle Security . . . . . . . . . . . . . . . . 34
Alert Lane Change . . . . . . . . . . . . . . . . . 270
Side Blind Zone (SBZA) . . . . . . 270
All-Season Tires . . . . . . . . . . . . . . . . 375
All-Terrain Tires . . . . . . . . . . . . . . . . . 377
Antilock Brake System (ABS) . . . 228 Warning Light . . . . . . . . . . . . . . . . . 138

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
Index 483
Capacities andSpecifications . . . . . . . . . . . . . . . . . 454
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . . . 216
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . 29
Winter Driving . . . . . . . . . . . . . . . . 194
Cargo
Tie-Downs . . . . . . . . . . . . . . . . . . . . .113
Caution, Danger, and Warning . . . . 3
Center Console Storage . . . . . . . . 111
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . . . 365
Center Seat . . . . . . . . . . . . . . . . . . . . . 53
Chains, Tire . . . . . . . . . . . . . . . . . . . . 400
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . 121
Charging System Light . . . . . . . . . 134
Check Engine Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . 135
Ignition Transmission Lock . . . 359
Child Restraints Infants and Young Children . . . . . 84
Lower Anchors and Tethersfor Children . . . . . . . . . . . . . . . . . . . 89
Older Children . . . . . . . . . . . . . . . . . . 82
Securing . . . . . . . . . . . . 102, 105, 106 Child Restraints (cont'd)
Systems . . . . . . . . . . . . . . . . . . . . . . . . 86
Circuit Breakers . . . . . . . . . . . . . . . . 366
Cleaning Exterior Care . . . . . . . . . . . . . . . . . 424
Interior Care . . . . . . . . . . . . . . . . . . 430
Climate Control Systems . . . . . . . 174
Air Conditioning . . . . . . . . . . . . . . 174
Dual Automatic . . . . . . . . . . . . . . . 176
Heating . . . . . . . . . . . . . . . . . . . . . . . 174
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Cluster, Instrument . . . . . . . . . . . . . 124
Collision Damage Repair . . . . . . . 465
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . .110
Compass . . . . . . . . . . . . . . . . . . . . . . . 118
Connected Services
Connections . . . . . . . . . . . . . . . . . . 479
Diagnostics . . . . . . . . . . . . . . . . . . . 480
Navigation . . . . . . . . . . . . . . . . . . . . 478
Connections
Connected Services . . . . . . . . . . 479
Control Hill Descent . . . . . . . . . . . . . . . . . . 233
Traction and ElectronicStability . . . . . . . . . . . . . . . . . . . . . 231
Control Light Hill Descent . . . . . . . . . . . . . . . . . . 139 Control of a Vehicle . . . . . . . . . . . . . 185
Convex Mirrors . . . . . . . . . . . . . . . . . . 37
Coolant
Engine Temperature Gauge . . 131
Engine TemperatureWarning Light . . . . . . . . . . . . . . . 141
Cooling . . . . . . . . . . . . . . . . . . . . 174, 176
Cooling System . . . . . . . . . . . . . . . . . 342
Courtesy Transportation
Program . . . . . . . . . . . . . . . . . . . . . . . 464
Cruise Control . . . . . . . . . . . . . . . . . . 239
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Cruise Control, Adaptive . . . . . . . . 242
Cupholders . . . . . . . . . . . . . . . . . . . . . 110
Customer Assistance . . . . . . . . . . . 461 Offices . . . . . . . . . . . . . . . . . . . . . . . . 460
Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . 461
Customer Information Publications OrderingInformation . . . . . . . . . . . . . . . . . . 467
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . 458
Cybersecurity . . . . . . . . . . . . . . . . . . . 470
D
Damage Repair, Collision . . . . . . . 465
Danger, Warning, and Caution . . . . 3