2015 GMC SIERRA 1500 warning light

Black plate (19,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Instruments and Controls 5-19
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF, or the symbol
for on and off, will light for several
seconds as a system check. Then,
after several more seconds, the
status indicator ON or OFF, or either
the on or off symbol, will light to let
you know the status of the front
outboard passenger frontal airbag.
When the front outboard passenger
frontal airbag is manually turned off
using the airbag on-off switch on the instrument panel endcap, the OFF
indicator light or the off symbol will
come on and stay on as a reminder
that the airbag has been turned off.
This light will go off when the airbag
has been turned on. See
Airbag
On-Off Switch on page 3-28 for
more information, including
important safety information.
{Warning
If the front outboard passenger
frontal airbag is turned off for a
person who is not in a risk group
identified by the national
government, that person will not
(Continued)
Warning (Continued)
have the extra protection of an
airbag. In a crash, the airbag will
not be able to inflate and help
protect the person sitting there.
Do not turn off the front outboard
passenger frontal airbag unless
the person sitting there is in a risk
group identified by the national
government. SeeAirbag On-Off
Switch on page 3-28 for more
information, including important
safety information.
{Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. For
example, the front outboard
(Continued)

Black plate (20,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-20 Instruments and Controls
Warning (Continued)
passenger frontal airbag could
inflate even though the airbag
on-off switch is turned off.
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.
If the word ON or the on symbol is
lit, it means that the front outboard
passenger frontal airbag is enabled
(may inflate). See Airbag On-Off
Switch on page 3-28 for more
information, including important
safety information.
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 airbag
on-off switch. See your dealer for
service.
Passenger Airbag Status
Indicator
If the vehicle has one of the
following indicators, then the vehicle
has a passenger sensing system for
the front outboard passenger
position unless there is an airbag
on-off switch on the instrument
panel endcap. If there is an airbag
on-off switch, the vehicle does not
have a passenger sensing system.
See Airbag On-Off Switch on
page 3-28.
The passenger airbag status
indicator is on the overhead
console. See Passenger Sensing
System on page 3-30 for important
safety information.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF, or the symbol
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.

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 (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 (26,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-26 Instruments and Controls
Tow/Haul Mode Light
For vehicles with the Tow/Haul
Mode feature, this light comes on
when the Tow/Haul Mode has been
activated.
SeeTow/Haul Mode on page 9-37.
Hill Descent Control Light
If equipped, the Hill Descent Control
light comes on steady when the
system is ready for use. When the
light flashes, the system is active. See
Hill Descent Control (HDC) on
page 9-52.
Lane Departure Warning
(LDW) Light
If equipped, this light briefly comes
on while starting the vehicle.
If it does not, have the vehicle
serviced by your dealer. If the
system is working normally, the
indicator light then turns off.
This light comes on green when the
system is on and ready to operate.
When the system determines that
the vehicle is leaving its lane
without using the turn signal, this
light will change to amber and flash.
See Lane Departure Warning (LDW)
on page 9-62.
Vehicle Ahead Indicator
If equipped, this light displays green
when a vehicle is detected ahead.
This light will display amber when
you are following a vehicle ahead
much too closely.
See Forward Collision Alert (FCA)
System on page 9-59.
Traction Off Light

Black plate (27,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Instruments and Controls 5-27
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your
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/StabiliTrak
button.
This light and the StabiliTrak OFF
light come on when StabiliTrak is
turned off.
If the TCS is off, wheel spin is not
limited. Adjust driving accordingly.
SeeTraction Control/Electronic
Stability Control on page 9-50.StabiliTrak®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
StabiliTrak system is turned off.
If StabiliTrak is off, the Traction
Control System (TCS) is also off.
If the StabiliTrak and TCS are off,
the system does not assist in
controlling the vehicle. Turn on the
TCS and the StabiliTrak systems
and the warning light turns off.
See Traction Control/Electronic
Stability Control on page 9-50.
Traction Control System
(TCS)/StabiliTrak®Light
This 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 StabiliTrak
system have been disabled. A DIC
message may display. Check the
DIC messages to determine which
feature(s) is no longer functioning
and whether the vehicle requires
service.

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.