engine GMC SIERRA 2021 Owner's Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
110 Instruments and Controls
Home :Press the thumbwheel to select the
available elements to display. Not all
elements will be available on all vehicles:
Speedometer, Speed Sign, Time, and Fuel
Range.
Display (Uplevel) : Press the thumbwheel to
enter the Display menu. Select to turn on or
off the compass or speed sign.
Speed Warning : The Speed Warning display
allows the driver to set a speed that they
do not want to exceed. To set the Speed
Warning, press the thumbwheel when Speed
Warning is displayed, or press the
thumbwheel on the main view to set the
speed value. Scroll to adjust the value. Press
the thumbwheel to set the speed. Once the
speed is set, this feature can be turned off
by pressing the thumbwheel while viewing
this page. If the selected speed limit is
exceeded, a pop-up warning is displayed
with a chime.
Software Information : Press the
thumbwheel while Software Information is
highlighted to display open source software
information.Speedometer
The speedometer shows the vehicle's speed
in either kilometers per hour (km/h) or
miles per hour (mph).
Odometer
The odometer shows how far the vehicle has
been driven, in either kilometers or miles.
Trip Odometer
The trip odometer shows how far the
vehicle has been driven since the trip
odometer was last reset.
The trip odometer is accessed and reset
through the Driver Information Center (DIC).
See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel and
Uplevel) 0125.
Tachometer
The tachometer displays the engine speed in
revolutions per minute (rpm).
For vehicles with the Stop/Start system,
when the ignition is on, the tachometer
indicates the vehicle status. When pointing
to AUTO STOP, the engine is off but the vehicle is on and can move. The engine
could auto start at any time. When the
indicator points to OFF, the vehicle is off.
When the engine is on, the tachometer will
indicate the engine’s revolutions per minute
(rpm). The tachometer may vary by several
hundred rpm, during Auto Stop mode, when
the engine is shutting off and restarting.
Fuel Gauge
Metric Uplevel Shown, Midlevel and Base
Level Similar

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Instruments and Controls 111
English Uplevel Shown, Midlevel and BaseLevel Similar
When the ignition is on, the fuel gauge
indicates about how much fuel is left in
the tank.
There is an arrow near the fuel gauge
pointing to the side of the vehicle the fuel
door is on.
When the indicator nears empty, the low
fuel light comes on. There still is a little fuel
left, but the vehicle should be refueled soon.
Here are three things that some owners ask
about. None of these show a problem with
the fuel gauge:
.It takes a little more, or less fuel to fill up
than the gauge indicated. For example,
the gauge may have indicated the tank
was half full, but it actually took a little
more, or less than half the tank's capacity
to fill the tank.
.The gauge moves a little while turning a
corner, speeding up or braking.
.The gauge takes a few seconds to
stabilize after the ignition is turned on
and goes back to empty when the
ignition is turned off.
Engine Oil Pressure Gauge
Uplevel Metric Shown, Base Level and Midlevel Similar
Uplevel English Shown, Base Level and
Midlevel Similar
The engine oil pressure gauge shows the
engine oil pressure in kPa (kilopascals)
or psi (pounds per square inch) when the
engine is running.
Oil pressure can vary with engine speed,
outside temperature, coolant temperature,
and oil viscosity.
On some models, the oil pump will vary
engine oil pressure according to engine
needs. Oil pressure may change quickly as
the engine speed or load varies. This is
normal. If the oil pressure warning light or
Driver Information Center (DIC) message

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
112 Instruments and Controls
indicates oil pressure outside the normal
operating range, check the vehicle's oil as
soon as possible.
SeeEngine Oil 0330.
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
Metric Uplevel Shown, Midlevel and Base Level Similar
English Uplevel Shown, Midlevel and Base Level 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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Instruments and Controls 113
Voltmeter Gauge
Uplevel Shown, Base Level and MidlevelSimilar
When the ignition is on, this gauge indicates
the battery voltage.
When the engine is running, this gauge
shows the condition of the charging system.
The gauge can transition from a higher to
lower or a lower to higher reading. This is
normal. If the vehicle is operating outside
the normal operating range, the charging
system light comes on. See Charging System
Light 0115. The voltmeter gauge may also
read lower when in fuel economy mode.
This is normal. Readings outside the normal operating
range can also occur when a large number
of electrical accessories are operating in the
vehicle and the engine is left idling for an
extended period. This condition is normal
since the charging system is not able to
provide full power at engine idle. As engine
speeds are increased, this condition should
correct itself as higher engine speeds allow
the charging system to create maximum
power.
The vehicle can only be driven for a short
time with the readings outside the normal
operating range. If the vehicle must be
driven, turn off all accessories, such as the
radio and air conditioner.
Readings outside the normal operating
range indicate a possible problem in the
electrical system. Have the vehicle serviced
as soon as possible.
Seat Belt Reminders
Driver Seat Belt Reminder Light
There is a driver seat belt reminder light on
the instrument cluster.
When the vehicle is started, this light
flashes and a chime may come on to remind
the driver to fasten their seat belt.
Then the light stays on solid until the belt is
buckled. This cycle may continue several
times if the driver remains or becomes
unbuckled while the vehicle is moving.
If the driver seat belt is buckled, neither the
light nor the chime comes on.
Front Passenger Seat Belt Reminder
Light
The vehicle may have a front passenger seat
belt reminder light near the passenger
airbag status indicator. See
Passenger
Sensing System 066.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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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 0114
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) 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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
116 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 Modifications0323.
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” underFilling the Tank (Pickup
Model) 0285 or
Filling the Tank (Chassis Cab Model) 0287. 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 (Except 6.2L
V8 Engine) 0283 or
Recommended Fuel (6.2L V8 Engine)
0 284.
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

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Instruments and Controls 117
service the vehicle may affect vehicle
operation. SeeAdd-On Electrical Equipment
0 318. See your dealer if assistance is
needed.
The vehicle may not pass inspection if:
.The light is on when the engine is
running.
.The light does not come on when the
ignition is on while the engine is off.
.Critical emission control systems have not
been completely diagnosed. If this
happens, the vehicle would not be ready
for inspection and might require
several days of routine driving before the
system is ready for inspection. This can
happen if the 12-volt battery has recently
been replaced or run down, or if the
vehicle has been recently serviced.
See your dealer if the vehicle will not pass
or cannot be made ready for the test.
Brake System Warning Light
MetricEnglish
This light should come on briefly when the
vehicle is turned on. If it does not come on
then, have it fixed so it will be ready to
warn you if there is a problem.
If the light comes on and stays on at start
up, there is a brake problem. Have the brake
system inspected right away.
If the light comes on while driving, pull off
the road and stop carefully. If equipped with
electric brake boost, vehicle speed may be
limited when the brake system warning
light comes on. The brake pedal might be
harder to push, or the brake pedal may go
closer to the floor. It could take longer to
stop. If the light is still on, have the vehicle
towed for service. See Towing the Vehicle
0 394.
{Warning
The brake system might not be working
properly if the brake system warning
light is on. Driving with the brake system
warning light on can lead to a crash.
If the light is still on after the vehicle has
been pulled off the road and carefully
stopped, have the vehicle towed for
service.
Electric Parking Brake Light
MetricEnglish
This light comes on when the parking brake
is applied. If the light continues flashing
after the parking brake is released, or while
driving, there is a problem with the Electric
Parking Brake system. A message may also
display in the Driver Information
Center (DIC).
If the light does not come on, or remains
flashing, see your dealer.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Instruments and Controls 121
serviced by your dealer. If the system is
working normally, the indicator light then
turns off. This light comes on when the
Electronic Stability Control (ESC) system is
turned off. If ESC is off, the Traction Control
System (TCS) is also off. To turn ESC off and
on, seeTraction Control/Electronic Stability
Control 0248.
If ESC and TCS are off, the systems do not
assist in controlling the vehicle. Adjust
driving accordingly.
Engine Coolant Temperature
Warning Light
This light comes on briefly while starting
the vehicle.
If it does not, have the vehicle serviced by
your dealer. If the system is working
normally the indicator light goes off.
Caution
The engine coolant temperature warning
light indicates that the vehicle has
overheated. Driving with this light on can
damage the engine and it may not be
covered by the vehicle warranty. See
Engine Overheating 0338.
The engine coolant temperature warning
light comes on when the engine has
overheated.
If this happens, pull over and turn off the
engine as soon as possible. See Engine
Overheating 0338.
Driver Mode Control Light
This light comes on when Sport Mode is
selected.
This light comes on when Snow/Ice Mode is
selected.
This light comes on when Terrain Mode is
selected.
This light comes on when Off-Road Mode is
selected.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
122 Instruments and Controls
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. SeeTire Pressure
0 367.
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
0 369.
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. If the light comes on and stays on, it means
that oil is not flowing through the engine
properly. The vehicle could be low on oil
and might have some other system
problem. See your dealer.
Low Fuel Warning Light
This light is near the fuel gauge and comes
on briefly when the ignition is turned on as
a check to show it is working.
It also comes on when the fuel tank is low
on fuel. The light turns off when fuel is
added. If it does not, have the vehicle
serviced.
Security Light

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Instruments and Controls 123
The security light should come on briefly as
the engine is started. If it does not come on,
have the vehicle serviced by your dealer.
If the system is working normally, the
indicator light turns off.
If the light stays on and the engine does
not start, there could be a problem with the
theft-deterrent system. SeeImmobilizer
Operation 032.
High-Beam On Light
This light comes on when the high-beam
headlamps are in use. See Headlamp High/
Low-Beam Changer 0141.
IntelliBeam Light
This light comes on when the IntelliBeam
system, if equipped, is enabled. See Exterior
Lamp Controls 0139.
Front Fog Lamp Light
For vehicles with fog lamps, this light comes
on when the fog lamps are on.
The light goes out when the fog lamps are
turned off. See Fog Lamps0143.
Lamps On Reminder
This light comes on when the exterior lamps
are in use, except when only the Daytime
Running Lamps (DRL) are active. See Exterior
Lamp Controls 0139.
Cruise Control Light
The cruise control light is white when the
cruise control is on and ready, and turns
green when the cruise control is set and
active.
See Cruise Control 0254.
Adaptive Cruise Control Light
If equipped, this light is white when the
Adaptive Cruise Control (ACC) is on and
ready, and turns green when the ACC is set
and active. When ACC is engaged and the
driver accelerates, the indicator will turn
blue. See Adaptive Cruise Control (Camera)
0 256.