warning light GMC SIERRA 2018 Owner's Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 147
passenger remains or becomes
unbuckled while the vehicle is
moving.
If the passenger seat belt is
buckled, neither the chime nor the
light comes on.
The front passenger seat belt
reminder light and chime may turn
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. The system check includes
the airbag sensor(s), passenger
sensing system (if equipped), the
pretensioners, the airbag modules,
the wiring, and the crash sensing
and diagnostic module. For more
information on the airbag system,
seeAirbag System 077.
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.
Airbag On-Off Light
If the vehicle has an airbag on-off
switch, it also has a passenger
airbag status indicator located in the
overhead console.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
148 Instruments and Controls
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. SeeAirbag
On-Off Switch 084 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
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. See Airbag On-Off
Switch 084 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
(Continued)
Warning (Continued)
with the airbag system. For
example, the front outboard
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 0147 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 084 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 149
Passenger Airbag Status
Indicator
If the vehicle has the passenger
sensing system, the overhead
console will have a passenger
airbag status indicator. See
Passenger Sensing System086 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.
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 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
(Continued)
Warning (Continued)
with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. SeeAirbag Readiness
Light 0147 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
152 Instruments and Controls
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 you 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.
If the light is still on, have the
vehicle towed for service. See
Towing the Vehicle
0430.
{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 the light does not come on, have it
fixed so it will be ready to warn if
there is a problem.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 153
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.
SeeBrake System Warning Light
0 152.
Four-Wheel-Drive Light
The four-wheel-drive light comes on
when the manual transfer case is
shifted into four-wheel drive and the
front axle engages. LO or HI will
also be next to this light when the
vehicle is in four-wheel low or
four-wheel high.
Some delay between the shifting
and the light coming on is normal.
See Four-Wheel Drive 0272.
Tow/Haul Mode Light
For vehicles with the Tow/Haul
Mode feature, this light comes on
when the Tow/Haul Mode has been
activated.
See Tow/Haul Mode 0271.
Hill Descent Control Light
If equipped, the Hill Descent Control
light comes on when the system is
ready for use. When the light
flashes, the system is active.
See Hill Descent Control (HDC)
0 284.
Lane Departure Warning
(LDW) Light (2500/3500)
If equipped, this light is green if
LDW is on and ready to operate.
This light changes to amber and
flashes to indicate that the lane
marking has been crossed without
using a turn signal in that direction.
On the base cluster, this light comes
on briefly while starting the vehicle.
If it does not come on, have the
vehicle serviced.
See Lane Departure Warning (LDW)
(2500/3500 Series) 0295.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
154 Instruments and Controls
Lane Keep Assist (LKA)
Light (1500 Series)
If available, this light comes on
briefly while starting the vehicle.
This light is green if LKA is available
to assist.
LKA may assist by gently turning
the steering wheel if the vehicle
approaches a detected lane marking
without using the turn signal in that
direction. The LKA light will turn
amber.
This light is amber and flashes as a
Lane Departure Warning (LDW)
alert, to indicate that the lane
marking has been crossed.
SeeLane Keep Assist (LKA) (1500
Series) 0297.
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 0292.
Traction Off Light
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.
See
Traction Control/Electronic
Stability Control 0282.
StabiliTrak OFF Light
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your
dealer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 155
This light comes on when the
StabiliTrak system is turned off.
If StabiliTrak is off, the Traction
Control System (TCS) is also off.
If 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.
SeeTraction Control/Electronic
Stability Control 0282.
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 Driver Information Center (DIC)
message may display. Check the
DIC messages to determine which
feature(s) is no longer functioning
and whether the vehicle requires
service.
If the light is on and flashing, the
TCS and/or the StabiliTrak system
is actively working.
See
Traction Control/Electronic
Stability Control 0282.
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
0363.
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 0363.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
156 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 0397. 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 0400.
Engine Oil Pressure Light
(Denali Only)
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 167
Maximum Startup Volume
This feature sets the maximum
startup volume. If the vehicle is
started and the volume is greater
than this level, the volume is
adjusted to this level. To set the
maximum startup volume, touch +
or−to increase or decrease.
Audio Cue Volume
This feature sets the volume of
audio files played at system startup
and shutdown.
Select On, then touch + or −to
increase or decrease the volume.
Vehicle
Select and the following may
display:
. Climate and Air Quality
. Collision/Detection Systems
. Comfort and Convenience
. Lighting
. Power Door Locks
. Remote Lock, Unlock, Start
Climate and Air Quality
Select and the following may
display:
.Auto Fan Speed
. Auto Rear Defog
Auto Fan Speed
This feature will set the auto fan
speed.
Select Low, Medium, or High.
Auto Rear Defog
This feature will automatically turn
on the rear defogger when it is cold
outside.
Select Off or On.
Collision/Detection Systems
Select and the following may
display:
. Alert Type
. Forward Collision System
. Park Assist Alert Type
This feature will set crash alerts to
beeps or seat vibrations. This
setting affects all crash alerts
including Forward Collision, Lane
Departure Warning, and Parking
Assist alerts.
Select Beeps or Safety Alert Seat.
Forward Collision System
This feature will turn on or off
Forward Collision Alert (FCA) and
Forward Automatic Braking (FAB).
The Off setting disables all FCA and
FAB functions. With the Alert and
Brake setting, both FCA and FAB
are available. The Alert setting
disables FAB. See
Forward
Automatic Braking (FAB) 0294.
Select Off, Alert and Brake, or Alert.
Park Assist
If equipped, this feature can assist
in backing up and parking the
vehicle. See Assistance Systems for
Parking or Backing 0289.
Select Off, On, or On with Towbar.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
176 Lighting
Lighting
Exterior Lighting
Exterior Lamp Controls . . . . . . . 176
Exterior Lamps OffReminder . . . . . . . . . . . . . . . . . . . 178
Headlamp High/Low-Beam Changer . . . . . . . . . . . . . . . . . . . . 179
Flash-to-Pass . . . . . . . . . . . . . . . . 179
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . 179
Automatic Headlamp System . . . . . . . . . . . . . . . . . . . . . . 179
Hazard Warning Flashers . . . . . 180
Turn and Lane-Change Signals . . . . . . . . . . . . . . . . . . . . . . 181
Fog Lamps . . . . . . . . . . . . . . . . . . . 181
Auxiliary Roof-Mounted Lamp . . . . . . . . 182
Interior Lighting
Instrument Panel IlluminationControl . . . . . . . . . . . . . . . . . . . . . . 182
Cargo Lamp . . . . . . . . . . . . . . . . . . 183
Dome Lamps . . . . . . . . . . . . . . . . . 183
Reading Lamps . . . . . . . . . . . . . . 183
Lighting Features
Entry Lighting . . . . . . . . . . . . . . . . 184
Exit Lighting . . . . . . . . . . . . . . . . . . 184
Battery Load Management . . . 184
Battery Power Protection . . . . . 185
Exterior Lighting Battery Saver . . . . . . . . . . . . . . . . . . . . . . . 185Exterior Lighting
Exterior Lamp Controls
The exterior lamp control is on the
instrument panel to the left of the
steering wheel.
O(Off) : Turns off the automatic
headlamps and Daytime Running
Lamps (DRL). Turn the headlamp
control to the off position again to
turn the automatic headlamps or
DRL back on.
For vehicles first sold in Canada, off
will only work when the vehicle is in
P (Park).