
Black plate (21,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Instruments and Controls 5-21
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
enabled (may inflate).
If the word OFF or the off symbol is
lit on the 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 on page 5-18 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.
See
Battery Voltage and Charging
Messages on page 5-35.
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.

Black plate (22,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-22 Instruments and Controls
Malfunction
Indicator Lamp
A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors the operation
of the vehicle to ensure emissions
are at acceptable levels, helping to
maintain a clean environment. The
malfunction indicator lamp comes
on when the vehicle is placed in
ON/RUN, as a check to show it is
working. If it does not, have the
vehicle serviced by your dealer. See
Ignition Positions on page 9-24.
If the malfunction indicator lamp
comes on while the engine is
running, this indicates that the OBD
II system has detected a problem
and diagnosis and service might be
required.Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system also
assists the service technician in
correctly diagnosing any
malfunction.
{Caution
If the vehicle is continually driven
with this light on, the emission
controls might not work as well,
the vehicle fuel economy might
not be as good, and the engine
might not run as smoothly. This
could lead to costly repairs that
might not be covered by the
vehicle warranty.
{Caution
Modifications made to the engine,
transmission, exhaust, intake,
or fuel system of the vehicle or
the replacement of the original
tires with other than those of the
same Tire Performance Criteria
(TPC) can affect the vehicle's
emission controls and can cause
this light to come on.
Modifications to these systems
could lead to costly repairs not
covered by the vehicle warranty.
This could also result in a failure
to pass a required Emission
Inspection/Maintenance test. See
Accessories and Modifications on
page 10-3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and

Black plate (24,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-24 Instruments and Controls
The DLC is under the instrument
panel to the left of the steering
wheel. See your dealer if assistance
is needed.
The vehicle may not pass
inspection if:
.The malfunction indicator lamp is
on with the engine running, or if
the light does not come on when
the ignition is turned to ON/RUN
while the engine is off. See your
dealer for assistance in verifying
proper operation of the
malfunction indicator lamp.
.The OBD II (On-Board
Diagnostics) system determines
that critical emission control
systems have not been
completely diagnosed. The
vehicle would be considered not
ready for inspection. This canhappen if the 12-volt battery has
recently been replaced or run
down. The diagnostic system is
designed to evaluate critical
emission control systems during
normal driving. This can take
several days of routine driving.
If this has been done and the
vehicle still does not pass the
inspection for lack of OBD II
system readiness, your dealer
can prepare the vehicle for
inspection.
Brake System Warning
Light
The vehicle brake system consists
of two hydraulic circuits. If one
circuit is not working, the remaining
circuit can still work to stop the
vehicle. For normal braking
performance, both circuits need to
be working.
If the warning light comes on, there
is a brake problem. Have the brake
system inspected right away.
MetricEnglish
This light should come on briefly
when the engine is started. If it does
not come on then, have it fixed so it
will be ready to warn if there is a
problem.
When the ignition is on, the brake
system warning light also comes on
when the parking brake is set. The
light stays on if the parking brake
does not fully release. If it stays on
after the parking brake is fully
released, it means the vehicle has a
brake problem.
If the light comes on while driving,
pull off the road and stop carefully.
The pedal might be harder to push,
or the pedal can go closer to the
floor. It may take longer to stop.

Black plate (25,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Instruments and Controls 5-25
If the light is still on, have the
vehicle towed for service. See
Towing the Vehicle on page 10-93.
{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.
Antilock Brake System
(ABS) Warning Light
This light comes on briefly when the
engine is started.
If it does not, have the vehicle
serviced by your dealer.
If the ABS light stays on, turn the
ignition off.
If the light comes on while driving,
stop as soon as it is safely possible
and turn off the vehicle. Then start
the engine again to reset the
system. If the ABS light stays on,
or comes on again while driving, the
vehicle needs service. A chime may
also sound when the light comes on
steady.
If the ABS light is the only light on,
the vehicle has regular brakes, but
the antilock brakes are not
functioning.
If both the ABS and the brake
system warning light are on, the
vehicle's antilock brakes are not
functioning and there is a problem
with the regular brakes. See your
dealer for service.See
Brake System Warning Light on
page 5-24 andBrake System
Messages on page 5-36.
Four-Wheel-Drive Light
The four-wheel-drive light comes on
when a vehicle with a manual
transfer case is shifted into
four-wheel drive and the front axle
engages.
Some delay between the shifting
and the light coming on is normal.
See Four-Wheel Drive on page 9-38
for more information.

Black plate (28,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-28 Instruments and Controls
If the indicator/warning light is on
and flashing, the TCS and/or the
StabiliTrak system is actively
working.
SeeTraction Control/Electronic
Stability Control on page 9-50.
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. See
Tire Messages on
page 5-42. Stop as soon as
possible, and inflate the tires to the
pressure value shown on the Tire
and Loading Information label. See
Tire Pressure on page 10-59.
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 on page 10-62.
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
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.

Black plate (36,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-36 Instruments and Controls
Brake System Messages
BRAKE FLUID LOW
This message is displayed when the
brake fluid level is low. SeeBrake
Fluid on page 10-29.
SERVICE BRAKE ASSIST
This message may be displayed
when there is a problem with the
brake boost assist system. When
this message is displayed, the brake
boost assist motor might be heard
operating and you might notice
pulsation in the brake pedal. This is
normal under these conditions. Take
the vehicle to your dealer for
service.
SERVICE TRAILER BRAKE
SYSTEM
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message displays and a chime
may sound when there is a problem
with the ITBC system. When this message displays, power
is no longer available to the trailer
brakes.
As soon as it is safe to do so,
carefully pull your vehicle over to
the side of the road and turn the
ignition off. Check the wiring
connection to the trailer and turn the
ignition back on. If this message still
displays, either your vehicle or the
trailer needs service. See your
dealer.
See
“Integrated Trailer Brake
Control System” underTowing
Equipment on page 9-87 for more
information.
Compass Messages
Dashes may be displayed if the
vehicle temporarily loses
communication with the Global
Positioning System (GPS).
Door Ajar Messages
DOOR OPEN
This message displays and a chime
may sound if a door is not fully
closed. Stop and turn off the
vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
HOOD OPEN
This message displays and a chime
may sound if the hood is not fully
closed. Stop and turn off the
vehicle, check the hood for
obstructions, and close the hood
again. Check to see if the message
still appears on the DIC.

Black plate (40,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-40 Instruments and Controls
SERVICE PARKING ASSIST
This message displays if there is a
problem with the Parking Assist
system. Do not use this system to
help you park. See your dealer for
service.
Ride Control System
Messages
SERVICE STABILITRAK
If this message displays, it means
there may be a problem with the
StabiliTrak system. If you see this
message, try to reset the system.
Stop; turn off the engine for at least
15 seconds; then start the engine
again. If this message still comes
on, it means there is a problem. You
should see your dealer for service.
The vehicle is safe to drive;
however, you do not have the
benefit of StabiliTrak, so reduce
your speed and drive accordingly.
SERVICE TRACTION
CONTROL
This message displays when there
is a problem with the Traction
Control System (TCS). When this
message displays, the system will
not limit wheel spin. Adjust your
driving accordingly. See your dealer
for service. SeeTraction Control/
Electronic Stability Control on
page 9-50.
STABILITRAK INITIALIZING
This message may come on if the
StabiliTrak system has not fully
initialized because of road
conditions or the incorrect tire size.
When the StabiliTrak system is fully
initialized, the message will turn off.
See Traction Control/Electronic
Stability Control on page 9-50. If this
message continues to be displayed
for multiple ignition cycles and on
different road surfaces, see your
dealer for service.
TRACTION CONTROL OFF
This message displays when the
traction control has been turned off.
See Traction Control/Electronic
Stability Control on page 9-50.
TRACTION CONTROL ON
This message displays when the
traction control is active. See
Traction Control/Electronic Stability
Control on page 9-50.
STABILITRAK OFF
This message displays when the
StabiliTrak system has been turned
off. Adjust your driving accordingly.
To limit wheel spin and realize the
full benefits of the stability
enhancement system, you should
normally leave StabiliTrak on. See
Traction Control/Electronic Stability
Control on page 9-50.

Black plate (42,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-42 Instruments and Controls
Tire Messages
SERVICE TIRE MONITOR
SYSTEM
If equipped with the Tire Pressure
Monitor System (TPMS), this
message displays if a part on the
system is not working properly. The
tire pressure light also flashes and
then remains on during the same
ignition cycle. SeeTire Pressure
Light on page 5-28. Several
conditions may cause this message
to appear. See Tire Pressure
Monitor Operation on page 10-62.
If the warning comes on and stays
on, there may be a problem with the
TPMS. See your dealer.
TIRE LEARNING ACTIVE
If equipped with the Tire Pressure
Monitor System (TPMS), this
message displays when the system
is relearning the tire positions on
your vehicle. The tire positions must
be relearned after rotating the tires
or after replacing a tire or sensor.
See Tire Inspection on page 10-66, Tire Rotation on page 10-61,
Tire
Pressure Monitor System on
page 10-61, and Tire Pressure on
page 10-59.
TIRE PRESSURE LOW ADD
AIR TO TIRE
If equipped with the Tire Pressure
Monitor System (TPMS), this
message displays when the
pressure in one or more of the
vehicle's tires is low. This message
also displays with a vehicle picture
to indicate the location of the low
tire. The low tire pressure warning
light will also come on. See Tire
Pressure Light on page 5-28. You
can receive more than one tire
pressure message at a time. If a tire
pressure message appears on the
DIC, stop as soon as you can. Have
the tire pressures checked and set
to those shown on the Tire and
Loading Information label. See Tires
on page 10-50, Vehicle Load Limits
on page 9-15, and Tire Pressure on
page 10-59. The DIC also shows
the tire pressure values. See
Driver Information Center (DIC)
(Base Level) on page 5-30 orDriver
Information Center (DIC) (Uplevel)
on page 5-32.
Transmission Messages
4WD OFF
If equipped with four-wheel drive,
this message displays when the
four-wheel-drive system is
temporarily disabled due to an
overheated condition. The vehicle
will run in two-wheel drive when this
message is present. Once the
four-wheel-drive system cools down,
the message turns off and the
four-wheel-drive system returns to
normal operation.
4WD SHIFT IN PROGRESS
This message will display while the
four-wheel-drive system is shifting.