check engine CHEVROLET SILVERADO 2500HD 2021 Owner's Manual

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
6 Introduction
23. Data Link Connector (DLC) (Out of View).SeeMalfunction Indicator Lamp (Check
Engine Light) 0111.
24. Electric Parking Brake 0240.
25. Fog Lamps 0138 (If Equipped).
Instrument Panel Illumination Control
0 140.
Exterior Cargo Lamps 0139.
Exterior Lamp Controls 0134.
Task Lighting 0139 (If Equipped).

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
20 Keys, Doors, and Windows
Remote Vehicle Start
If equipped with the remote start feature,
the climate control system will come on
when the vehicle is started remotely,
depending on the outside temperature.
The rear defog and heated and ventilated
seats, if equipped, may also come on. See
Heated and Ventilated Front Seats049 and
Vehicle Personalization 0126.
If equipped, the automatic heated steering
wheel may also come on. See Heated
Steering Wheel 096.
Laws in some communities may restrict the
use of remote starters. Check local
regulations for any requirements on remote
starting of vehicles.
Do not use remote start if the vehicle is low
on fuel. The vehicle may run out of fuel.
The vehicle cannot be remote started if:
.The RKE transmitter is inside the vehicle
or if the key is in the ignition.
.The hood is not closed.
.There is an emission control system
malfunction and the lamp is on.
.The ignition is in any mode other
than off.
.The hazard warning flashers are on.
.Two remote starts or a remote start with
an extension have been used.
.The vehicle is not in P (Park).
The engine will turn off during a remote
vehicle start if:
.The coolant temperature gets too high.
.The oil pressure gets low.
The RKE transmitter range may be reduced
while the vehicle is running.
Other conditions can affect the performance
of the transmitter. See Remote Keyless Entry
(RKE) System 010.
Starting the Engine Using Remote Start
1. Press and release
Q.
2. Immediately press and hold
/until the
turn signal lamps flash or for at least
four seconds.
When the vehicle starts, the parking
lamps will turn on. The doors will be
locked and the climate control system
may come on.
The engine will continue to run for
15 minutes. After 30 seconds, repeat
Steps 1 and 2 for a 15-minute time
extension. Turn the ignition on to operate the vehicle.
Extending Engine Run Time
The engine run time can be extended by
15 minutes, for a total of 30 minutes,
if during the first 15 minutes Steps 1 and 2
are repeated while the engine is still
running. An extension can be requested
30 seconds after starting.
A maximum of two remote starts, or a
single start with an extension, is allowed
between ignition cycles.
The vehicle's ignition must be turned on and
then back off to use remote start again.
Canceling a Remote Start
To cancel a remote start, do one of the
following:.Press and hold/until the parking lamps
turn off.
.Turn on the hazard warning flashers.
.Turn the ignition on and then off.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
30 Keys, Doors, and Windows
It may be necessary to check the fuse. See
Fuses and Circuit Breakers0329. If the
engine still does not start with the other
key, the vehicle needs service. If the vehicle
does start, the first key may be faulty. See
your dealer. It is possible for the
immobilizer system to learn new or
replacement keys. Up to eight keys can be
programmed for the vehicle. To program
additional keys, see Keys (Key Access)07or
Keys (Keyless Access) 09. Do not leave the
key or device that disarms or deactivates
the vehicle theft system in the vehicle.
See your dealer to get a new key blank cut
exactly as the ignition key that operates the
system.
Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things, like
other vehicles, look farther away than
they really are. If you cut too sharply
into the right lane, you could hit a
(Continued)
Warning (Continued)
vehicle on the right. Check the inside
mirror or glance over your shoulder
before changing lanes.
Standard Mirrors
The passenger side mirror is convex shaped.
A convex mirror's surface is curved so more
can be seen from the driver seat.
Trailer-Tow Mirrors
The upper portion of both the driver and
passenger mirrors is flat.
The lower portion of both the driver and
passenger mirrors is convex. A convex
mirror’s surface is curved so more can be
seen from the driver seat. The lower portion
is adjusted manually.
Manual Mirrors
If equipped, adjust manual mirrors by
moving the mirror up and down or left to
right to see a little of the side of the vehicle
and to have a clear view behind the vehicle. Using hood-mounted air deflectors and
add-on convex mirror attachments could
decrease mirror performance.
Trailer-Tow Mirrors
Extending Mirrors
Trailer tow mirrors can extend out for better
visibility when towing a trailer.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Seats and Restraints 51
{Warning
A seat belt that is improperly routed, not
properly attached, or twisted will not
provide the protection needed in a crash.
The person wearing the belt could be
seriously injured. After raising the rear
seatback, always check to be sure that
the seat belts are properly routed and
attached, and are not twisted.
Heated Rear Seats
{Warning
If you cannot feel temperature change or
pain to the skin, the seat heater may
cause burns. See the Warning under
Heated and Ventilated Front Seats049.
If available, the buttons are on the rear of
the center console. To operate, the engine
must be running.
Press
MorLto heat the left or right
outboard seat cushion. An indicator on the
climate control display appears when this
feature is on.
This feature turns on at the highest setting.
With each press of the button, the heated
seat changes to the next lower setting, and
then the off setting. Three lights indicate
the highest setting, and one light indicates
the lowest. If the heated seats are on high,
the level may automatically be lowered
after approximately 30 minutes.
Seat Belts
This section describes how to use seat belts
properly, and some things not to do.
{Warning
Do not let anyone ride where a seat belt
cannot be worn properly. In a crash,
if you or your passenger(s) are not
wearing seat belts, injuries can be much
worse than if you are wearing seat belts.
You can be seriously injured or killed by
hitting things inside the vehicle harder or
by being ejected from the vehicle. In
addition, anyone who is not buckled up
can strike other passengers in the vehicle.
It is extremely dangerous to ride in a
cargo area, inside or outside of a vehicle.
In a collision, passengers riding in these
areas are more likely to be seriously
injured or killed. Do not allow passengers
to ride in any area of the vehicle that is
not equipped with seats and seat belts.
Always wear a seat belt, and check that
all passenger(s) are restrained
properly too.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Instruments and Controls 95
Instruments and Controls
Controls
Steering Wheel Adjustment . . . . . . . . . . . . 96
Steering Wheel Controls . . . . . . . . . . . . . . . 96
Heated Steering Wheel . . . . . . . . . . . . . . . . . 96
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Windshield Wiper/Washer . . . . . . . . . . . . . . 97
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Power Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Wireless Charging . . . . . . . . . . . . . . . . . . . . . . 99
Warning Lights, Gauges, and Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Instrument Cluster . . . . . . . . . . . . . . . . . . . . . 102
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . 106
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Fuel Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Engine Oil Pressure Gauge . . . . . . . . . . . . . 107
Engine Coolant Temperature Gauge . . . 108
Voltmeter Gauge . . . . . . . . . . . . . . . . . . . . . . 109
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . 109
Airbag Readiness Light . . . . . . . . . . . . . . . . . 110
Passenger Airbag Status Indicator . . . . . . 110
Charging System Light . . . . . . . . . . . . . . . . . 111 Malfunction Indicator Lamp (Check
Engine Light) . . . . . . . . . . . . . . . . . . . . . . . . . 111
Brake System Warning Light . . . . . . . . . . . 113
Electric Parking Brake Light . . . . . . . . . . . . 113
Service Electric Parking Brake Light . . . . . 113
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . 114
Tow/Haul Mode Light . . . . . . . . . . . . . . . . . . 114
Hill Descent Control Light . . . . . . . . . . . . . . 114
Lane Departure Warning (LDW) Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Vehicle Ahead Indicator . . . . . . . . . . . . . . . . 115
Traction Off Light . . . . . . . . . . . . . . . . . . . . . . 115
Traction Control System (TCS)/Electronic Stability Control Light . . . . . . . . . . . . . . . . 115
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Driver Mode Control Light . . . . . . . . . . . . . 117
Tire Pressure Light . . . . . . . . . . . . . . . . . . . . . 117
Engine Oil Pressure Light (Uplevel Cluster) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Low Fuel Warning Light . . . . . . . . . . . . . . . . 118
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . 118
High-Beam On Light . . . . . . . . . . . . . . . . . . . 118
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . 118
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 118
Cruise Control Light . . . . . . . . . . . . . . . . . . . . 119 Door Ajar Light . . . . . . . . . . . . . . . . . . . . . . . . 119
Information Displays
Driver Information Center (DIC) (Base
Level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Driver Information Center (DIC) (Midlevel and Uplevel) . . . . . . . . . . . . . . . 120
Head-Up Display (HUD) . . . . . . . . . . . . . . . . 123
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . . . . . . . . . . . 125
Engine Power Messages . . . . . . . . . . . . . . . 126
Vehicle Speed Messages . . . . . . . . . . . . . . . 126
Vehicle Personalization
Vehicle Personalization . . . . . . . . . . . . . . . . 126
Universal Remote System
Universal Remote System . . . . . . . . . . . . . . 131
Universal Remote System Programming . . . . . . . . . . . . . . . . . . . . . . . . . 131
Universal Remote System Operation . . . 133

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
102 Instruments and Controls
Warning Lights, Gauges, and
Indicators
Warning lights and gauges can signal that
something is wrong before it becomes
serious enough to cause an expensive repair
or replacement. Paying attention to the
warning lights and gauges could prevent
injury.
Some warning lights come on briefly when
the engine is started to indicate they are
working. When one of the warning lights
comes on and stays on while driving,
or when one of the gauges shows there
may be a problem, check the section that
explains what to do. Waiting to do repairs
can be costly and even dangerous.
Instrument Cluster
Base Cluster English Shown, Metric Similar
1.Tachometer 0106
2. Engine Oil Pressure Gauge 0107
3. Engine Coolant Temperature Gauge
0108
4. Fuel Gauge 0106
5. Voltmeter Gauge 0109
6. Speedometer 0106 7.
Driver Information Center (DIC) (Base
Level) 0119 or
Driver Information Center (DIC)
(Midlevel and Uplevel) 0120

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
108 Instruments and Controls
indicates oil pressure outside the normal
operating range, check the vehicle's oil as
soon as possible.
SeeEngine Oil 0305.
Caution
Lack of proper engine oil maintenance
can damage the engine. Driving with the
engine oil low can also damage the
engine. The repairs would not be covered
by the vehicle warranty. Check the oil
level as soon as possible. Add oil if
required, but if the oil level is within the
operating range and the oil pressure is
still low, have the vehicle serviced.
Always follow the maintenance schedule
for changing engine oil.
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
Engine Coolant Temperature
Gauge
Uplevel Metric Shown, Base Level and Midlevel Similar
Uplevel English Shown, Base Level and Midlevel Similar
This gauge measures the temperature of the
vehicle's engine coolant.
While driving under normal operating
conditions, if the needle moves into the red
warning area, the engine is too hot. Pull off
the road, stop the vehicle, and turn off the
engine as soon as possible.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Instruments and Controls 111
will light either ON or OFF, or either the on
or off symbol, to let you know the status of
the front outboard passenger frontal airbag.
If the word ON or the on symbol is lit on
the passenger airbag status indicator, it
means that the front outboard passenger
frontal airbag is allowed to inflate.
If the word OFF or the off symbol is lit on
the passenger airbag status indicator, it
means that the passenger sensing system
has turned off the front outboard passenger
frontal airbag.
If, after several seconds, both status
indicator lights remain on, or if there are no
lights at all, there may be a problem with
the lights or the passenger sensing system.
See your dealer for service.
{Warning
If the airbag readiness light ever comes
on and stays on, it means that
something may be wrong with the airbag
system. To help avoid injury to yourself
or others, have the vehicle serviced right
away. SeeAirbag Readiness Light 0110
for more information, including important
safety information.
Charging System Light
The charging system light comes on briefly
when the ignition is turned on, but the
engine is not running, as a check to show
the light is working. It should go out when
the engine is started.
If the light stays on, or comes on while
driving, there may be a problem with the
electrical charging system. Have it checked
by your dealer. Driving while this light is on
could drain the battery.
When this light comes on, or is flashing, the
Driver Information Center (DIC) also displays
a message.
If a short distance must be driven with the
light on, be sure to turn off all accessories,
such as the radio and air conditioner. Find a
safe place to stop the vehicle.
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. See Ignition Positions (Keyless
Access) 0226 or
Ignition Positions (Key Access) 0224.
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.

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
112 Instruments and Controls
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 Modifications0302.
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)
0 265 or
Filling the Tank (Chassis Cab and Box
Delete Models) 0266. 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.
.Poor fuel quality can cause inefficient
engine operation and poor driveability,
which may go away once the engine is
warmed up. If this occurs, change the fuel
brand. It may require at least one full
tank of the proper fuel to turn the light
off. See Recommended Fuel 0263.
If the light remains on, see your dealer.
Emissions Inspection and Maintenance
Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument panel to
the left of the steering wheel. Connecting
devices that are not used to perform an
Emissions Inspection/Maintenance test or to
service the vehicle may affect vehicle

Chevrolet Silverado 2500 HD/3500 HD Owner Manual (GMNA-Localizing-U.
S./Canada/Mexico-14632154) - 2021 - CRC - 11/20/20
Instruments and Controls 117
If this happens, pull over and turn off the
engine as soon as possible. SeeEngine
Overheating 0312.
Driver Mode Control Light
This light comes on when Snow/Ice Mode is
selected.
This light comes on when Off-Road Mode is
selected.
See Driver Mode Control 0244.
Tire Pressure Light
For vehicles with the Tire Pressure Monitor
System (TPMS), this light comes on briefly
when the engine is started. It provides
information about tire pressures and
the TPMS.
When the Light Is On Steady
This indicates that one or more of the tires
are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display. Stop as
soon as possible, and inflate the tires to the
pressure value shown on the Tire and
Loading Information label. See Tire Pressure
0 341.
When the Light Flashes First and Then Is On
Steady
If the light flashes for about a minute and
then stays on, there may be a problem with
the TPMS. If the problem is not corrected, the light will come on at every ignition
cycle. See
Tire Pressure Monitor Operation
0 343.
Engine Oil Pressure Light (Uplevel
Cluster)
Caution
Lack of proper engine oil maintenance
can damage the engine. Driving with the
engine oil low can also damage the
engine. The repairs would not be covered
by the vehicle warranty. Check the oil
level as soon as possible. Add oil if
required, but if the oil level is within the
operating range and the oil pressure is
still low, have the vehicle serviced.
Always follow the maintenance schedule
for changing engine oil.
This light should come on briefly as the
engine is started. If it does not come on,
have the vehicle serviced by your dealer.