service indicator GMC SIERRA 2020 Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Introduction 3
Danger, Warning, and
Caution
Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{Danger
Danger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{Warning
Warning indicates a hazard that
could result in injury or death.
Caution
Caution indicates a hazard that
could result in property or vehicle
damage.
A circle with a slash through it is a
safety symbol which means“Do
Not,” “Do not do this,” or“Do not let
this happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M: Shown when the owner ’s
manual has additional instructions
or information.
*: Shown when the service
manual has additional instructions
or information.
0: Shown when there is more
information on another page —
“see page.” Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. See the
features in this manual for
information.
u:
Air Conditioning System
G:Air Conditioning Refrigerant Oil
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
$:Brake System Warning Light
9:Dispose of Used Components
Properly
P: Do Not Apply High Pressure
Water
B: Engine Coolant Temperature
_: Flame/Fire Prohibited
H:Flammable
[:Forward Collision Alert
R: Fuse Block Cover Lock
Location
+: Fuses
j:ISOFIX/LATCH System Child
Restraints

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
78 Seats and Restraints
The vehicle has a feature that may
automatically unlock the doors, turn
on the interior lamps and hazard
warning flashers, and shut off the
fuel system after the airbags inflate.
The feature may also activate,
without airbag inflation, after an
event that exceeds a predetermined
threshold. After turning the ignition
off and then on again, the fuel
system will return to normal
operation; the doors can be locked,
the interior lamps can be turned off,
and the hazard warning flashers can
be turned off using the controls for
those features. If any of these
systems are damaged in the crash
they may not operate as normal.
{Warning
A crash severe enough to inflate
the airbags may have also
damaged important functions in
the vehicle, such as the fuel
system, brake and steering
systems, etc. Even if the vehicle
appears to be drivable after a(Continued)
Warning (Continued)
moderate crash, there may be
concealed damage that could
make it difficult to safely operate
the vehicle.
Use caution if you should attempt
to restart the engine after a crash
has occurred.
In many crashes severe enough to
inflate the airbag, windshields are
broken by vehicle deformation.
Additional windshield breakage may
also occur from the front outboard
passenger airbag.
. Airbags are designed to inflate
only once. After an airbag
inflates, you will need some new
parts for the airbag system.
If you do not get them, the
airbag system will not be there
to help protect you in another
crash. A new system will include
airbag modules and possibly
other parts. The service manual
for the vehicle covers the need
to replace other parts. .
The vehicle has a crash sensing
and diagnostic module which
records information after a
crash. See Vehicle Data
Recording and Privacy 0474
and
Event Data Recorders 0475.
. Let only qualified technicians
work on the airbag systems.
Improper service can mean that
an airbag system will not work
properly. See your dealer for
service.
Passenger Sensing
System
The vehicle has a passenger
sensing system for the front
outboard passenger position. The
passenger airbag status indicator
will light on the overhead console
when the vehicle is started.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
80 Seats and Restraints
Warning (Continued)
secure child restraints in the rear
seat. Consider using another
vehicle to transport the child
when a rear seat is not available.
If the vehicle does not have a rear
seat that will accommodate a
rear-facing child restraint, a
rear-facing child restraint should not
be installed in the vehicle, even if
the airbag is off.
The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag if:
. The front outboard passenger
seat is unoccupied.
. The system determines an infant
is present in a child restraint.
. A front outboard passenger
takes his/her weight off of the
seat for a period of time.
. There is a critical problem with
the airbag system or the
passenger sensing system. When the passenger sensing
system has turned off the front
outboard passenger frontal airbag,
the OFF indicator will light and stay
lit as a reminder that the airbag is
off. See
Passenger Airbag Status
Indicator 0137.
The passenger sensing system is
designed to turn on the front
outboard passenger frontal airbag
anytime the system senses that a
person of adult size is sitting
properly in the front outboard
passenger seat.
When the passenger sensing
system has allowed the airbag to be
enabled, the ON indicator will light
and stay lit as a reminder that the
airbag is active.
For some children, including
children in child restraints, and for
very small adults, the passenger
sensing system may or may not turn
off the front outboard passenger
frontal airbag, depending upon the
person's seating posture and body
build. Everyone in the vehicle who
has outgrown child restraints should wear a seat belt properly
—whether
or not there is an airbag for that
person.
{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. See Airbag Readiness
Light 0136 for more information,
including important safety
information.
If the On Indicator Is Lit for a
Child Restraint
The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag if
the system determines that an infant
is present in a child restraint. If a
child restraint has been installed
and the ON indicator is lit:
1. Turn the vehicle off.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
118 Instruments and Controls
Instruments and
Controls
Controls
Steering Wheel Adjustment . . . 119
Steering Wheel Controls . . . . . . 120
Heated Steering Wheel . . . . . . . 120
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Windshield Wiper/Washer . . . . 120
Compass . . . . . . . . . . . . . . . . . . . . . 121
Clock . . . . . . . . . . . . . . . . . . . . . . . . . 121
Power Outlets . . . . . . . . . . . . . . . . 122
Wireless Charging . . . . . . . . . . . . 124
Warning Lights, Gauges, and
Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . 126
Instrument Cluster . . . . . . . . . . . . 127
Speedometer . . . . . . . . . . . . . . . . . 131
Odometer . . . . . . . . . . . . . . . . . . . . . 132
Trip Odometer . . . . . . . . . . . . . . . . 132
Tachometer . . . . . . . . . . . . . . . . . . . 132
Fuel Gauge . . . . . . . . . . . . . . . . . . . 132
Engine Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . . 133
Engine Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 134 Voltmeter Gauge . . . . . . . . . . . . . 135
Seat Belt Reminders . . . . . . . . . 136
Airbag Readiness Light . . . . . . . 136
Passenger Airbag Status
Indicator . . . . . . . . . . . . . . . . . . . . 137
Charging System Light . . . . . . . 138
Malfunction Indicator Lamp (Check Engine Light) . . . . . . . . 138
Brake System Warning Light . . . . . . . . . . . . . . . . . . . . . . . . 140
Electric Parking Brake Light . . . . . . . . . . . . . . . . . . . . . . . . 141
Service Electric Parking Brake Light . . . . . . . . . . . . . . . . . . . . . . . . 141
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . 141
Four-Wheel-Drive Light . . . . . . . 142
Tow/Haul Mode Light . . . . . . . . . 142
Hill Descent Control Light . . . . 142
Lane Departure Warning (LDW) Light (2500/3500
Series) . . . . . . . . . . . . . . . . . . . . . . 142
Lane Keep Assist (LKA) Light (1500 Series) . . . . . . . . . . . . . . . 143
Vehicle Ahead Indicator . . . . . . 143
Pedestrian Ahead Indicator . . . 143
Traction Off Light . . . . . . . . . . . . . 143
Traction Control System (TCS)/ Electronic Stability Control
Light . . . . . . . . . . . . . . . . . . . . . . . . 144 Electronic Stability Control
(ESC) Off Light . . . . . . . . . . . . . . 144
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . 145
Driver Mode Control Light . . . . 145
Tire Pressure Light . . . . . . . . . . . 145
Engine Oil Pressure Light
(Uplevel Cluster) . . . . . . . . . . . . 146
Low Fuel Warning Light . . . . . . 146
Security Light . . . . . . . . . . . . . . . . . 147
High-Beam On Light . . . . . . . . . . 147
Front Fog Lamp Light . . . . . . . . . 147
Lamps On Reminder . . . . . . . . . 147
Cruise Control Light . . . . . . . . . . 147
Door Ajar Light . . . . . . . . . . . . . . . 148
Information Displays
Driver Information Center (DIC) (Base Level) . . . . . . . . . . . . . . . . 148
Driver Information Center (DIC) (Midlevel and Uplevel) . . . . . . 149
Head-Up Display (HUD) . . . . . . 152
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . 156
Engine Power Messages . . . . . 156
Vehicle Speed Messages . . . . . 156
Vehicle Personalization
Vehicle Personalization . . . . . . . 157

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
126 Instruments and Controls
2. Redistributions in binary formmust reproduce the above
copyright notice, this list of
conditions and the following
disclaimer in the
documentation and/or other
materials provided with the
distribution.
3. Neither the name of the copyright holder nor the names
of its contributors may be used
to endorse or promote products
derived from this software
without specific prior written
permission.
THIS SOFTWARE IS PROVIDED
BY THE COPYRIGHT HOLDERS
AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED
WARRANTIES OF
MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT
SHALL THE COPYRIGHT HOLDER
OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED
TO, PROCUREMENT OF
SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF
THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Instruments and Controls 133
Uplevel English Fuel Gauge
Shown, Base Level and Midlevel Fuel Gauge 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 four things that some
owners ask about. None of these
show a problem with the fuel gauge: .
At the service station, the fuel
pump shuts off before the gauge
reads full.
. 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 or speeding up.
. 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Instruments and Controls 137
The airbag readiness light comes on
for several seconds when the
vehicle is started. If the light does
not come on then, have it fixed
immediately.
{Warning
If the airbag readiness light stays
on after the vehicle is started or
comes on while driving, it means
the airbag system might not be
working properly. The airbags in
the vehicle might not inflate in a
crash, or they could even inflate
without a crash. To help avoid
injury, have the vehicle serviced
right away.
If there is a problem with the airbag
system, a Driver Information Center
(DIC) message may also come on.
Passenger Airbag Status
Indicator
The vehicle has a passenger
sensing system. See Passenger
Sensing System 078 for important safety information. The overhead
console has a passenger airbag
status indicator.
United States
Canada
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF, or the
symbols for on and off, for several
seconds as a system check. Then,
after several more seconds, the
status indicator 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
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
138 Instruments and Controls
Warning (Continued)
away. SeeAirbag Readiness
Light 0136 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.
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)
0
208 or
Ignition Positions (Key Access)
0 210.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Instruments and Controls 143
SeeLane Departure Warning (LDW)
(2500/3500 Series) 0276.
Lane Keep Assist (LKA)
Light (1500 Series)
After the vehicle is started, this light
turns off and stays off if LKA has not
been turned on or is unavailable.
If available, this light is white if LKA
is turned on, but not ready to assist.
This light is green if LKA is turned
on and is ready to assist.
LKA may assist by gently turning
the steering wheel if the vehicle
approaches a detected lane
marking. The LKA light is amber
when assisting.
This light flashes amber as a Lane
Departure Warning (LDW) alert, to
indicate that the lane marking has
been crossed. LKA will not assist or alert if the turn
signal is active in the direction of
lane departure, or if LKA detects
that you are accelerating, braking,
or actively steering.
See
Lane Keep Assist (LKA) (1500
Series) 0278.
Vehicle Ahead Indicator
If equipped, this indicator will
display green when a vehicle is
detected ahead and amber when
you are following a vehicle ahead
much too closely.
See Forward Collision Alert (FCA)
System 0268.
Pedestrian Ahead
Indicator
If equipped, this indicator will
display amber when a nearby
pedestrian is detected in front of the
vehicle.
See Front Pedestrian Braking (FPB)
System (1500 Series) 0272.
Traction Off Light
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
144 Instruments and Controls
dealer. If the system is working
normally, the indicator light then
turns off.
The traction off light comes on when
the Traction Control System (TCS)
has been turned off by pressing and
releasing the TCS/ESC button.
This light and the Electronic Stability
Control (ESC) OFF light come on
when ESC is turned off.
If the TCS is off, wheel spin is not
limited. Adjust driving accordingly.
SeeTraction Control/Electronic
Stability Control 0235.
Traction Control System
(TCS)/Electronic Stability
Control Light
If equipped, the Electronic Stability
Control (ESC) or TCS indicator/
warning light comes on briefly when
the engine is started.
If the light 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 is on and not flashing, the
TCS, and potentially the ESC
system have been disabled.
If the indicator/warning light is on
and flashing, the TCS and/or the
ESC system is actively working.
See Traction Control/Electronic
Stability Control 0235.
Trailer Sway Control Light
(Uplevel Cluster)
This light will flash when Trailer
Sway Control is active. See Trailer
Sway Control (TSC) 0308.
Electronic Stability
Control (ESC) Off Light
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your
dealer.
This light comes on when the ESC
system is turned off. If ESC is off,
the Traction Control System (TCS)
is also off.
If the ESC and TCS are off, the
system does not assist in controlling
the vehicle. Turn on the TCS and
the ESC systems and the warning
light turns off.
See Traction Control/Electronic
Stability Control 0235.