2018 GMC SIERRA warning light

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).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
180 Lighting
There is a light sensor on top of the
instrument panel. Do not cover the
sensor, otherwise the headlamps
will come on when they are not
needed.
The system may also turn on the
headlamps when driving through a
parking garage or tunnel.
If the vehicle is started in a dark
garage, the automatic headlamp
system comes on immediately. If it
is light outside when the vehicle
leaves the garage, there is a slight
delay before the automatic
headlamp system changes to the
DRL. During that delay, the
instrument cluster may not be as
bright as usual. Make sure the
instrument panel brightness controlis in the full bright position. See
Instrument Panel Illumination
Control
0182.
When it is bright enough outside,
the headlamps will turn off or may
change to Daytime Running
Lamps (DRL).
The automatic headlamp system
turns off when the exterior lamp
control is turned toOor the ignition
is off.
Lights On with Wipers
If the windshield wipers are
activated in daylight with the engine
on, and the exterior lamp control is
in AUTO, the headlamps, parking
lamps, and other exterior lamps
come on. The transition time for the
lamps coming on varies based on
wiper speed. When the wipers are
not operating, these lamps turn off.
Move the exterior lamp control to
O
or;to disable this feature.
Hazard Warning Flashers
|: Press this button to make the
front and rear turn signal lamps
flash on and off. Press again to turn
the flashers off.
When the hazard warning flashers
are on, the vehicle's turn signals will
not work.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
242 Driving and Operating
Warning (Continued)
Apply the brakes lightly when
descending a hill and use a low
gear to keep vehicle speed under
control.
If the vehicle stalls on a hill: 1. Apply the brakes to stop the vehicle, and then apply the
parking brake.
2. Shift into P (Park) and then restart the engine.
.If driving uphill when the
vehicle stalls, shift to
R (Reverse), release the
parking brake, and back
straight down.
. Never try to turn the vehicle
around. If the hill is steep
enough to stall the vehicle,
it is steep enough to cause
it to roll over.
. If you cannot make it up the
hill, back straight down
the hill. .
Never back down a hill in
N (Neutral) using only the
brake. The vehicle can roll
backward quickly and you
could lose control.
. If driving downhill when the
vehicle stalls, shift to a
lower gear, release the
parking brake, and drive
straight down the hill.
3. If the vehicle cannot be restarted after stalling, set the
parking brake, shift into
P (Park), and turn the
vehicle off.
3.1. Leave the vehicle and seek help.
3.2. Stay clear of the path the vehicle would take if it
rolled downhill.
. Avoid turns that take the vehicle
across the incline of the hill.
A hill that can be driven straight
up or down might be too steep to
drive across. Driving across an
incline puts more weight on the downhill wheels, which could
cause a downhill slide or a
rollover.
. Surface conditions can be a
problem. Loose gravel, muddy
spots, or even wet grass can
cause the tires to slip sideways,
downhill. If the vehicle slips
sideways, it can hit something
that will trip it —a rock, a rut,
etc. —and roll over.
. Hidden obstacles can make the
steepness of the incline more
severe. If a rock is driven across
with the uphill wheels, or if the
downhill wheels drop into a rut
or depression, the vehicle can tilt
even more.
. If an incline must be driven
across, and the vehicle starts to
slide, turn downhill. This should
help straighten out the vehicle
and prevent the side slipping.