2021 CHEVROLET SILVERADO 1500 gas tank

Chevrolet Silverado 1500 Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico/Paraguay-14632303) - 2021 - CRC - 11/9/20
116 Instruments and Controls
Malfunction Indicator Lamp
(Check Engine Light)
This light is part of the vehicle’s emission
control on-board diagnostic system. If this
light is on while the engine is running, a
malfunction has been detected and the
vehicle may require service. The light should
come on to show that it is working when
the ignition is on and the engine is not
running. SeeIgnition Positions (Keyless
Access) 0230 or
Ignition Positions (Key Access) 0229.
Malfunctions are often indicated by the
system before any problem is noticeable.
Being aware of the light and seeking service
promptly when it comes on may prevent
damage.
Caution
If the vehicle is driven continually with
this light on, the emission control system
may not work as well, the fuel economy
may be lower, and the vehicle may not
run smoothly. This could lead to costly
repairs that might not be covered by the
vehicle warranty.
Caution
Modifications to the engine, transmission,
exhaust, intake, or fuel system, or the
use of replacement tires that do not
meet the original tire specifications, can
cause this light to come on. This could
lead to costly repairs not covered by the
vehicle warranty. This could also affect
the vehicle’s ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications 0322.
If the light is flashing : A malfunction has
been detected that could damage the
emission control system and increase vehicle
emissions. Diagnosis and service may be
required. To help prevent damage, reduce vehicle
speed and avoid hard accelerations and
uphill grades. If towing a trailer, reduce the
amount of cargo being hauled as soon as
possible.
If the light continues to flash, find a safe
place to park. Turn the vehicle off and wait
at least 10 seconds before restarting the
engine. If the light is still flashing, follow
the previous guidelines and see your dealer
for service as soon as possible.
If the light is on steady :
A malfunction has
been detected. Diagnosis and service may be
required.
Check the following:
.If fuel has been added to the vehicle
using the capless funnel adapter, make
sure that it has been removed. See
“Filling the Tank with a Portable Gas Can”
under Filling the Tank (Pickup Model)
0 285 or
Filling the Tank (Chassis Cab Model) 0286. The diagnostic system can
detect if the adapter has been left
installed in the vehicle, allowing fuel to
evaporate into the atmosphere. A few
driving trips with the adapter removed
may turn off the light.

Chevrolet Silverado 1500 Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico/Paraguay-14632303) - 2021 - CRC - 11/9/20
284 Driving and Operating
Prohibited Fuels
Caution
Do not use fuels with any of the
following conditions; doing so may
damage the vehicle and void its
warranty:
.For vehicles that are not FlexFuel, fuel
labeled greater than 15% ethanol by
volume, such as mid-level ethanol
blends (16–50% ethanol), E85,
or FlexFuel.
.Fuel with any amount of methanol,
methylal, ferrocene, and aniline. These
fuels can corrode metal fuel system
parts or damage plastic and rubber
parts.
.Fuel containing metals such as
methylcyclopentadienyl manganese
tricarbonyl (MMT), which can damage
the emissions control system and
spark plugs.
.Fuel with a posted octane rating of
less than the recommended fuel. Using
this fuel will lower fuel economy and
performance, and may decrease the
life of the emissions catalyst.
Fuels in Foreign Countries
The U.S., Canada, and Mexico post fuel
octane ratings in anti-knock index (AKI). For
fuel not to use in a foreign country, see
Prohibited Fuels0284.
Fuel Additives
TOP TIER Detergent Gasoline is highly
recommended for use with your vehicle.
If your country does not have TOP TIER
Detergent Gasoline, add ACDelco Fuel
System Treatment Plus−Gasoline to the
vehicle’s gasoline fuel tank at every oil
change or 15 000 km (9,000 mi), whichever
occurs first. TOP TIER Detergent Gasoline and
ACDelco Fuel System Treatment Plus
−Gasoline will help keep your vehicle’s
engine fuel deposit free and performing
optimally.
E85 or FlexFuel
Vehicles with a yellow fuel sticker on the
fuel door can use either unleaded gasoline
or fuel containing up to 85% ethanol (E85).
All other vehicles should use only the
unleaded gasoline as described in
Recommended Fuel (Except 6.2L V8 Engine)
0283 or
Recommended Fuel (6.2L V8 Engine) 0283. The use of E85 or FlexFuel is encouraged
when the vehicle is designed to use it. E85
or FlexFuel is made from renewable sources.
To help locate fuel stations that carry E85 or
FlexFuel, the U.S. Department of Energy has
an alternative fuel website. See
www.afdc.energy.gov/afdc/locator/stations.
E85 or FlexFuel should meet ASTM
Specification D 5798 or CAN/CGSB–3.512 in
Canada. Do not use the fuel if the ethanol
content is greater than 85%. Fuel mixtures
that do not meet ASTM or CGSB
specifications can affect driveability and
could cause the malfunction indicator lamp
to come on.
The starting characteristics of E85 or FlexFuel
make it unsuitable for use when
temperatures fall below
−18 °C (0 °F). Use
gasoline or add gasoline to the E85 or
FlexFuel.
Because E85 or FlexFuel has less energy per
liter (gallon) than gasoline, the vehicle will
need to be refilled more often. See Filling
the Tank (Pickup Model) 0285 or
Filling the Tank (Chassis Cab Model) 0286.

Chevrolet Silverado 1500 Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico/Paraguay-14632303) - 2021 - CRC - 11/9/20
Driving and Operating 285
The only GM approved aftermarket additive
is ACDelco Fuel System Treatment
Plus-FlexFuel. Follow the instructions on the
bottle for proper use. This product is
available at your GM dealer.
Caution
Some additives are not compatible with
E85 or FlexFuel and can harm the
vehicle's fuel system. Use only additives
approved by GM for E85 or FlexFuel
vehicles. Damage caused by unapproved
additives would not be covered by the
vehicle warranty.
Caution
Do not use fuel containing methanol.
It can corrode metal parts in the fuel
system and also damage plastic and
rubber parts. That damage would not be
covered under the vehicle warranty.
To help keep the engine running efficiently,
fill the tank with gasoline, up to E15, after
filling the tank with E85 one or two times.
Filling the Tank (Pickup Model)
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
An arrow on the fuel gauge indicates which
side of the vehicle the fuel door is on. See
Fuel Gauge 0110.
{Warning
Fuel vapors and fuel fires burn violently
and can cause injury or death.
Follow these guidelines to help avoid
injuries to you and others:
.Read and follow all the instructions on
the fuel pump island.
.Turn off the engine when refueling.
.Keep sparks, flames, and smoking
materials away from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices while
refueling.
.Do not re-enter the vehicle while
pumping fuel.
(Continued)
Warning (Continued)
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.
.Fuel can spray out if the fill nozzle is
inserted too quickly. This spray can
happen if the tank is nearly full, and is
more likely in hot weather. Insert the
fill nozzle slowly and wait for any hiss
noise to stop before beginning to
flow fuel.

Chevrolet Silverado 1500 Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico/Paraguay-14632303) - 2021 - CRC - 11/9/20
336 Vehicle Care
Check to see if coolant is visible in the
coolant surge tank. If the coolant inside the
coolant surge tank is boiling, wait until it
cools down. The coolant level should be at
or above the indicated mark. If it is not,
there may be a leak in the cooling system.
If coolant is visible but the coolant level is
not at or above the indicated mark, see the
following sections on how to add coolant to
the coolant surge tank following.
Automatic Coolant Service Fill
Instructions (L3B Engine)
This feature assists in filling and removing
air from the cooling system after service of
components or when coolant is added after
being too low.
To activate the fill and air removal process:1. Remove the coolant surge tank pressure cap when the cooling system, including
the coolant surge tank pressure cap and
upper radiator hose, is no longer hot.
Turn the pressure cap; slowly
counterclockwise about one full turn. If a
hiss is heard, wait for that to stop.
A hiss means there is still some
pressure left.
2. Keep turning the pressure cap slowly, and remove it. 3. Fill the coolant surge tank with the
proper mixture to the indicated mark.
4. Connect the vehicle to a battery charger.
5. Set the ignition to service mode, see Ignition Positions (Keyless Access) 0230
or
Ignition Positions (Key Access) 0229.
6. Turn off the air conditioning.
7. Set the parking brake.
8. At the same time, press the accelerator and the brake for automatic vehicles for
two seconds, then release.
9. Listen for pump activation and movement of the control valves while
watching the level of the coolant in the
surge tank. Add fluid as the level drops
below the indicated mark on the surge
tank. Allow 15 minutes for the fill and air
removal process to complete.
10. Reinstall the surge tank cap.
If the tank empties, turn the ignition off,
allow the Electronic Control Module (ECM) to
go to sleep, about two minutes, refill to the
indicated mark, and repeat Steps 5–9.
How to Add Coolant to the Coolant
Surge Tank for Gasoline Engines
Except L3B
If the vehicle has a diesel engine, see
“Cooling System” in the Duramax diesel
supplement for the proper coolant fill
procedure.
{Warning
Spilling coolant on hot engine parts can
burn you. Coolant contains ethylene
glycol and it will burn if the engine parts
are hot enough.
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
the wrong mixture, the engine could get
too hot but there would not be an
overheat warning. The engine could catch
fire and you or others could be burned.

Chevrolet Silverado 1500 Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico/Paraguay-14632303) - 2021 - CRC - 11/9/20
OnStar 441
.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 1500 Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico/Paraguay-14632303) - 2021 - CRC - 11/9/20
452 Index
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Filter, Engine Air Cleaner . . . . . . . . . . . . . . . . . . . . . 333
Fixed Mast Antenna . . . . . . . . . . . . . . . . . . . . . .158
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Flashers, Hazard Warning . . . . . . . . . . . . . . . . .142
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Floor Console Storage . . . . . . . . . . . . . . . . . . . . . 97
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
Fluid Automatic Transmission . . . . . . . . . . . . . . . 332
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
Four-Wheel Drive Transfer Case . . . . . . . . 241
Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Fog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Forward Collision Alert (FCA) System . . . . 274
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . 241, 345
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . . . . 118
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Front Fog Lamp
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Heated and Ventilated . . . . . . . . . . . . . . . . . . 52
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Economy, Driving for Better . . . . . . . . . . . 212
Filling a Portable Fuel Container . . . . . . . 288
Filling the Tank . . . . . . . . . . . . . . . . . . . 285, 286
Foreign Countries . . . . . . . . . . . . . . . . . . . . . . 284
Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Low Fuel Warning Light . . . . . . . . . . . . . . . 122
Management, Active . . . . . . . . . . . . . . . . . . . 237
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . 284
Recommended . . . . . . . . . . . . . . . . . . . . . . . . . 283
Top Tier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . . . . 391
Fuses Engine Compartment Fuse Block . . . . . . . 353
Fuses and Circuit Breakers . . . . . . . . . . . . . 353
Instrument Panel Fuse Block . . . . . . 357, 358
G
Garage Door Opener . . . . . . . . . . . . . . . . . . . . . 136Programming . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Gauges Engine Coolant Temperature . . . . . . . . . . . . 112
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . . 111
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . . 110
Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Warning Lights and Indicators . . . . . . . . . 106
General Information Service and Maintenance . . . . . . . . . . . . . . 408
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Glass Replacement . . . . . . . . . . . . . . . . . . . . . . . 347
Global Positioning System (GPS) . . . . . . . . . .174
Glove Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
GM Mobility Reimbursement
Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .431
Guidance
Problems with the Route . . . . . . . . . . . . . . 174