2020 GMC SIERRA DENALI service

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Instruments and Controls 141
If both the ABS warning light and
the brake system warning light are
on, ABS is not functioning and there
is a problem with the regular brakes.
See your dealer for service.
SeeBrake System Warning Light
0 139.
Four-Wheel-Drive Light
Auto Mode Shown, Other Modes
Similar
If equipped, the four-wheel-drive
light displays what mode the vehicle
is in. The light will show each mode:
2WD, 4HI, AUTO (all transfer
cases); 4LOW and N (two-speed
transfer case only).
The light will flash when a shift is in
progress. Once the shift is complete
the light will be steady. If the light turns amber, there may
be a malfunction with the
four-wheel-drive system. See your
dealer.
See
Four-Wheel Drive 0227.
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 0227.
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)
0 237.
Lane Departure Warning
(LDW) Light (2500/3500
Series)
If equipped, this light comes on
briefly while starting the vehicle. If it
does not come on, have the vehicle
serviced.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
142 Instruments and Controls
SeeLane Departure Warning (LDW)
(2500/3500 Series) 0276.
Lane Keep Assist (LKA)
Light (1500 Series)
After the vehicle is started, this light
turns off and stays off if LKA has not
been turned on or is unavailable.
If available, this light is white if LKA
is turned on, but not ready to assist.
This light is green if LKA is turned
on and is ready to assist.
LKA may assist by gently turning
the steering wheel if the vehicle
approaches a detected lane
marking. The LKA light is amber
when assisting.
This light flashes amber as a Lane
Departure Warning (LDW) alert, to
indicate that the lane marking has
been crossed. LKA will not assist or alert if the turn
signal is active in the direction of
lane departure, or if LKA detects
that you are accelerating, braking,
or actively steering.
See
Lane Keep Assist (LKA) (1500
Series) 0278.
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 0268.
Pedestrian Ahead
Indicator
If equipped, this indicator will
display amber when a nearby
pedestrian is detected in front of the
vehicle.
See Front Pedestrian Braking (FPB)
System (1500 Series) 0272.
Traction Off Light
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Instruments and Controls 143
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/ESC button.
This light and the Electronic Stability
Control (ESC) OFF light come on
when ESC is turned off.
If the TCS is off, wheel spin is not
limited. Adjust driving accordingly.
SeeTraction Control/Electronic
Stability Control 0235.
Traction Control System
(TCS)/Electronic Stability
Control Light
If equipped, the Electronic Stability
Control (ESC) or TCS indicator/
warning 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 ESC
system have been disabled.
If the indicator/warning light is on
and flashing, the TCS and/or the
ESC system is actively working.
See Traction Control/Electronic
Stability Control 0235.
Trailer Sway Control Light
(Uplevel Cluster)
This light will flash when Trailer
Sway Control is active. See Trailer
Sway Control (TSC) 0308.
Electronic Stability
Control (ESC) 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 ESC
system is turned off. If ESC is off,
the Traction Control System (TCS)
is also off.
If the ESC and TCS are off, the
system does not assist in controlling
the vehicle. Turn on the TCS and
the ESC systems and the warning
light turns off.
See Traction Control/Electronic
Stability Control 0235.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
144 Instruments and Controls
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 Overheating0351. 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 0351.
Driver Mode Control Light
This light comes on when Sport
Mode is selected (1500 Series).
This light comes on when Snow/Ice
Mode is selected.
This light comes on when Terrain
Mode is selected (1500 Series).
This light comes on when Off-Road
Mode is selected.
Tire Pressure Light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Instruments and Controls 145
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 0387.
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 0390.Engine Oil Pressure Light
(Uplevel Cluster)
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.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
146 Instruments and Controls
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.
If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system. SeeImmobilizer Operation
0 37.
High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer 0167.
IntelliBeam Light
This light comes on when the
IntelliBeam system, if equipped, is
enabled. See Exterior Lamp
Controls 0165.
Front Fog Lamp Light
For vehicles with fog lamps, this
light comes on when the fog lamps
are on. The light goes out when the fog
lamps are turned off. See
Fog
Lamps 0170.
Lamps On Reminder
This light comes on when the
exterior lamps are in use, except
when only the Daytime Running
Lamps (DRL) are active. See
Exterior Lamp Controls 0165.
Cruise Control Light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Instruments and Controls 155
Clean the HUD lens with a soft cloth
sprayed with glass cleaner. Wipe
the lens gently, then dry it.
HUD Troubleshooting
Check that:
.Nothing is covering the
HUD lens.
. The HUD brightness setting is
not too dim or too bright.
. The HUD is adjusted to the
proper height.
. Polarized sunglasses are
not worn.
. The windshield and HUD lens
are clean.
If the HUD image is not correct,
contact your dealer.
The windshield is part of the HUD
system. See Windshield
Replacement 0365.
Vehicle Messages
Messages displayed on the Driver
Information Center (DIC) indicate
the status of the vehicle or some
action that may be needed to
correct a condition. Multiple
messages may appear one after
another.
The messages that do not require
immediate action can be
acknowledged and cleared by
pressing the thumbwheel. The
messages that require immediate
action cannot be cleared until that
action is performed.
All messages should be taken
seriously; clearing the message
does not correct the problem.
If a SERVICE message appears,
see your dealer.
Follow the instructions given in the
messages. The system displays
messages regarding the following
topics:
.
Service Messages
. Fluid Levels .
Vehicle Security
. Brakes
. Steering
. Ride Control Systems
. Driver Assistance Systems
. Cruise Control
. Lighting and Bulb Replacement
. Wiper/Washer Systems
. Doors and Windows
. Seat Belts
. Airbag Systems
. Engine and Transmission
. Tire Pressure
. Battery
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays when the
vehicle's propulsion power is
reduced. A reduction in propulsion
power can affect the vehicle's ability
to accelerate. If this message is on,
but there is no observed reduction

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
156 Instruments and Controls
in performance, proceed to your
destination. The performance may
be reduced the next time the vehicle
is driven. The vehicle may be driven
while this message is on, but
maximum acceleration and speed
may be reduced. Anytime this
message stays on, or displays
repeatedly, the vehicle should be
taken to your dealer for service as
soon as possible.
Under certain operating conditions,
propulsion will be disabled. Try
restarting after the vehicle has been
off for 30 seconds.
Vehicle Speed Messages
SPEED LIMITED TO
XXX KM/H (MPH)
This message shows that the
vehicle speed has been limited to
the speed displayed. The limited
speed is a protection for various
propulsion and vehicle systems,
such as lubrication, thermal, brakes,
suspension, Teen Driver if
equipped, or tires.
Vehicle
Personalization
The following are all possible
vehicle personalization features.
Depending on the vehicle, some
may not be available.
For System, Apps, and Personal
features and functions, see
“Settings”in the infotainment
manual.
To access the vehicle
personalization menu:
1. Touch the Settings icon on the Home Page of the infotainment
display.
2. Touch Vehicle to display a list of available options.
3. Touch to select the desired feature setting.
4. Touch
9orRto turn a feature
off or on.
5. Touch
zto go to the top level
of the Settings menu. The menu may contain the
following:
Rear Seat Reminder
This allows for a chime and a
message when the rear door has
been opened before or during
operation of the vehicle.
Touch Off or On.
Climate and Air Quality
Touch and the following may
display:
.
Auto Fan Speed
. Auto Defog
. Auto Rear Defog
Auto Fan Speed
This setting specifies the amount of
airflow when the climate control fan
setting is Auto Fan.
Touch Low, Medium, or High.
Auto Defog
This setting automatically directs air
to the windshield to assist in
defogging, based on temperature
and humidity conditions.