2023 GMC SIERRA service indicator

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Introduction 3
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
Q:Keep Fuse Block Covers Properly
Installed
|: Lane Change Alert
@:Lane Departure Warning
A:Lane Keep Assist
*: Malfunction Indicator Lamp
::Oil Pressure
X:Park Assist
~:Pedestrian Ahead Indicator
O:Power
7:Rear Cross Traffic Alert
I:Registered Technician
/:Remote Vehicle Start
h:Risk of Electrical Fire

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
70 Seats and Restraints
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 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 0405 and
Event Data Recorders 0406.
.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.
United States
Canada
The words ON and OFF, or the symbols for
on and off, will be visible during the system
check. When the system check is complete,
either the word ON or OFF, or the symbol
for on or off, will be visible. See Passenger
Airbag Status Indicator 0119.
The passenger sensing system turns off the
front outboard passenger frontal airbag
under certain conditions. No other airbag is
affected by the passenger sensing system.
The passenger sensing system works with
sensors that are part of the front outboard
passenger seat and seat belt. The sensors
are designed to detect the presence of a
properly seated occupant and determine if
the front outboard passenger frontal airbag
should be allowed to inflate or not.
According to accident statistics, children are
safer when properly secured in a rear seat
in the correct child restraint for their weight
and size.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
72 Seats and Restraints
{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 0119
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.
2. Remove the child restraint from the vehicle.
3. Remove any additional items from the seat such as blankets, cushions, seat
covers, seat heaters, or seat massagers. 4. Reinstall the child restraint following the
directions provided by the child restraint
manufacturer and refer to Securing Child
Restraints (With the Seat Belt in the
Center Front Seat) 099 or
Securing Child Restraints (With the Seat
Belt in the Rear Seat) 092 or
Securing Child Restraints (With the Seat
Belt in the Front Passenger Seat) 096.
Make sure the seat belt retractor is
locked by pulling the shoulder belt all
the way out of the retractor when
installing the child restraint, even if the
child restraint is equipped with a seat
belt lock off. When the retractor lock is
set, the belt can be tightened but not
pulled out of the retractor.
5. If, after reinstalling the child restraint and restarting the vehicle, the ON
indicator is still lit, turn the vehicle off.
Then slightly recline the vehicle seatback
and adjust the seat cushion,
if adjustable, to make sure that the
vehicle seatback is not pushing the child
restraint into the seat cushion.
Also make sure the child restraint is not
trapped under the vehicle head restraint.
If this happens, adjust the head restraint.
See Head Restraints 049. 6. Restart the vehicle.
The passenger sensing system may or may
not turn off the airbag for a child in a child
restraint depending upon the child’s size.
It is better to secure child restraints in the
rear seat. Consider using another vehicle to
transport the child when a rear seat is not
available. Never put a rear-facing child
restraint in the front seat, even if the ON
indicator is not lit.
If the Off Indicator Is Lit for an
Adult-Sized Occupant
If a person of adult size is sitting in the
front outboard passenger seat, but the OFF
indicator is lit, it could be because that
person is not sitting properly in the seat or

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Seats and Restraints 73
that the child restraint locking feature is
engaged. Use the following steps to allow
the system to detect that person and enable
the front outboard passenger frontal airbag:1. Turn the vehicle off.
2. Remove any additional material from the seat, such as blankets, cushions, seat
covers, seat heaters, or seat massagers.
3. Place the seatback in the fully upright position.
4. Have the person sit upright in the seat, centered on the seat cushion, with legs
comfortably extended.
5. If the shoulder portion of the belt is pulled out all the way, the child restraint
locking feature will be engaged. This
may unintentionally cause the passenger
sensing system to turn the airbag off for
some adult-sized occupants. If this
happens, unbuckle the belt, let the belt
go back all the way, and then buckle the
belt again without pulling the belt out
all the way.
6. Restart the vehicle and have the person remain in this position for two to
three minutes after the ON indicator
is lit.{Warning
If the front outboard passenger airbag is
turned off for an adult-sized occupant,
the airbag will not be able to inflate and
help protect that person in a crash,
resulting in an increased risk of serious
injury or even death. An adult-sized
occupant should not ride in the front
outboard passenger seat, if the passenger
airbag OFF indicator is lit.
Additional Factors Affecting System
Operation
Seat belts help keep the passenger in
position on the seat during vehicle
maneuvers and braking, which helps the
passenger sensing system maintain the
passenger airbag status. See “Seat Belts”
and “Child Restraints” in the Index for
additional information about the importance
of proper restraint use.
A thick layer of additional material, such as
a blanket or cushion, or aftermarket
equipment such as seat covers, seat heaters,
and seat massagers can affect how well the
passenger sensing system operates. We
recommend that you not use seat covers or
other aftermarket equipment except when approved by GM for your specific vehicle.
See
Adding Equipment to the
Airbag-Equipped Vehicle 074 for more
information about modifications that can
affect how the system operates.
The ON indicator may be lit if an object,
such as a briefcase, handbag, grocery bag,
laptop, or other electronic device, is put on
an unoccupied seat. If this is not desired,
remove the object from the seat.
{Warning
Stowing articles under the passenger seat
or between the passenger seat cushion
and seatback may interfere with the
proper operation of the passenger
sensing system.
Servicing the Airbag-Equipped
Vehicle
Airbags affect how the vehicle should be
serviced. There are parts of the airbag
system in several places around the vehicle.
Your dealer and the service manual have
information about servicing the vehicle and
the airbag system. To purchase a service
manual, see Publication Ordering
Information 0404.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
104 Instruments and Controls
Instruments and Controls
Controls
Steering Wheel Adjustment . . . . . . . . . . . 105
Heated Steering Wheel . . . . . . . . . . . . . . . . 105
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Windshield Wiper/Washer . . . . . . . . . . . . 106
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Power Outlets . . . . . . . . . . . . . . . . . . . . . . . . . 107
Wireless Charging . . . . . . . . . . . . . . . . . . . . . 109
Warning Lights, Gauges, and Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Instrument Cluster . . . . . . . . . . . . . . . . . . . . . 111
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . . 115
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Fuel Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Engine Oil Pressure Gauge . . . . . . . . . . . . . 116
Engine Coolant Temperature Gauge . . . . 117
Voltmeter Gauge . . . . . . . . . . . . . . . . . . . . . . 118
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . 118
Airbag Readiness Light . . . . . . . . . . . . . . . . . 119
Passenger Airbag Status Indicator . . . . . . 119
Charging System Light . . . . . . . . . . . . . . . . 120
Malfunction Indicator Lamp (Check Engine Light) . . . . . . . . . . . . . . . . . . . . . . . . 120 Brake System Warning Light . . . . . . . . . . . 122
Electric Parking Brake Light . . . . . . . . . . . . 122
Service Electric Parking Brake Light . . . . 122
Antilock Brake System (ABS) Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . 123
Hill Descent Control Light . . . . . . . . . . . . . . 123
Lane Departure Warning (LDW) Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Vehicle Ahead Indicator . . . . . . . . . . . . . . . . 124
Traction Off Light . . . . . . . . . . . . . . . . . . . . . . 124
Traction Control System (TCS)/Electronic Stability Control Light . . . . . . . . . . . . . . . . 124
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Driver Mode Control Light . . . . . . . . . . . . . 125
Tire Pressure Light . . . . . . . . . . . . . . . . . . . . . 126
Engine Oil Pressure Light (Uplevel Cluster) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Low Fuel Warning Light . . . . . . . . . . . . . . . . 127
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . 127
High-Beam On Light . . . . . . . . . . . . . . . . . . . 127
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . 128
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 128
Cruise Control Light . . . . . . . . . . . . . . . . . . . . 128
Door Ajar Light . . . . . . . . . . . . . . . . . . . . . . . . 128
Information Displays
Driver Information Center (DIC) (Base Level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Driver Information Center (DIC) (Midlevel and Uplevel) . . . . . . . . . . . . . . . 130
Head-Up Display (HUD) . . . . . . . . . . . . . . . . 132
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . . . . . . . . . . . 135
Engine Power Messages . . . . . . . . . . . . . . . 135
Vehicle Speed Messages . . . . . . . . . . . . . . . 135
Universal Remote System
Universal Remote System . . . . . . . . . . . . . . 135
Universal Remote System
Programming . . . . . . . . . . . . . . . . . . . . . . . . 136
Universal Remote System Operation . . . 137

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
118 Instruments and Controls
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 0120. 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 070.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Instruments and Controls 119
When the vehicle is started, this light
flashes and a chime may come on to remind
passengers to fasten their seat belt.
Then the light stays on solid until the belt is
buckled. This cycle continues several times if
the front passenger remains or becomes
unbuckled while the vehicle is moving.
If the front passenger seat belt is buckled,
neither the chime nor the light comes on.
The front passenger seat belt reminder light
and chime may come on if an object is put
on the seat such as a briefcase, handbag,
grocery bag, laptop, or other electronic
device. To turn off the reminder light and/or
chime, remove the object from the seat or
buckle the seat belt.
Airbag Readiness Light
This light shows if there is an electrical
problem with the airbag system. It is
located in the instrument cluster. The
system check includes the airbag sensor(s),
the passenger sensing system, the
pretensioners, the airbag modules, the
wiring, and the crash sensing and diagnostic
module. For more information on the airbag
system, seeAirbag System 065.
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 070 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

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
120 Instruments and Controls
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 0119
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 (Key Access)
0 221 or
Ignition Positions (Keyless Access) 0223.
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.