2020 CHEVROLET SILVERADO check engine

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
288 Driving and Operating
the drive mode that is
appropriate for the road
conditions.
Caution
If the vehicle tires begin to spin
and the vehicle begins to slide
toward the water, remove your
foot from the accelerator pedal
and apply the brake pedal. Seek
help to have the vehicle towed up
the ramp.
Maintenance when Trailer
Towing
The vehicle needs service more
often when used to tow trailers. See
Maintenance Schedule0437. It is
especially important to check the
engine oil, axle lubricant, belts,
cooling system, and brake system
before and during each trip.
Check periodically to see that all
nuts and bolts on the trailer hitch
are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 347.
Trailer Towing
If equipped with a diesel engine,
see the Duramax diesel
supplement.
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer
for important information about
towing a trailer with the vehicle.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy. Successful, safe trailering takes
correct equipment, and it has to be
used properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. Read this section
carefully before pulling a trailer.
Trailer Weight
{Warning
Never exceed the towing capacity
for your vehicle.
Safe trailering requires monitoring
the weight, speed, altitude, road
grades, outside temperature, and
how frequently the vehicle is used to
tow a trailer.
Trailer Weight Ratings
When towing a trailer, the combined
weight of the vehicle, vehicle
contents, trailer, and trailer contents

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
326 Vehicle Care
Vehicle Checks
Doing Your Own
Service Work
{Warning
It can be dangerous to work on
your vehicle if you do not have
the proper knowledge, service
manual, tools, or parts. Always
follow owner’s manual procedures
and consult the service manual
for your vehicle before doing any
service work.
If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, see
Publication Ordering Information
0 467.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing the
Airbag-Equipped Vehicle 080. If equipped with remote vehicle
start, open the hood before
performing any service work to
prevent remote starting the vehicle
accidentally. See
Remote Vehicle
Start 024.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0452.
Caution
Even small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
For vehicles with auto engine
stop/start, turn the vehicle off
before opening the hood. If the
(Continued)
Warning (Continued)
vehicle is on, the engine will start
when the hood is opened. You or
others could be injured.
{Warning
Components under the hood can
get hot from running the engine.
To help avoid the risk of burning
unprotected skin, never touch
these components until they have
cooled, and always use a glove or
towel to avoid direct skin contact.
Clear any snow from the hood
before opening.
To open the hood: 1. Pull the hood release lever with the
isymbol. It is on the
lower left side of the instrument
panel.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13337620) - 2020 - CTC - 1/27/20
Vehicle Care 329
1. Remote Negative (–) Location.See Jump Starting - North
America 0415.
2. Positive (+) Terminal (Under Cover). See Jump Starting -
North America 0415.
3. Battery - North America 0354.
4. Engine Compartment Fuse
Block 0367.
5. Engine Cooling Fans (Out of View). See Cooling System
0 342.
6. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0335.
7. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0335.
8. Coolant Surge Tank and Pressure Cap. See Cooling
System 0342.
9. Engine Air Cleaner/Filter 0340.
10. Brake Fluid Reservoir. See Brake Fluid 0353. 11. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 350.