light GMC YUKON 2020 Service Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Instruments and Controls 137
If towing a trailer, reduce the
amount of cargo being hauled as
soon as possible.
If the light continues to flash, find a
safe place to park. Turn the vehicle
off and wait at least 10 seconds
before restarting the engine. If the
light is still flashing, follow the
previous guidelines and see your
dealer for service as soon as
possible.
If the light is on steady :A
malfunction has been detected.
Diagnosis and service may be
required.
Check the following:
. If fuel has been added to the
vehicle using the capless fuel
funnel adapter, make sure that it
has been removed. See “Filling
the Tank with a Portable Gas
Can” under Filling the Tank
0 256. The diagnostic system
can detect if the adapter has
been left installed in the vehicle,
allowing fuel to evaporate into the atmosphere. A few driving
trips with the adapter removed
may turn off the light.
. Poor fuel quality can cause
inefficient engine operation and
poor driveability, which may go
away once the engine is warmed
up. If this occurs, change the
fuel brand. It may require at
least one full tank of the proper
fuel to turn the light off. See
Recommended Fuel (L83 5.3L
V8 Engine) 0254 or
Recommended Fuel (L86 6.2L
V8 Engine) 0254.
If the light remains on, see your
dealer.
Emissions Inspection and
Maintenance Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the
test equipment will likely connect to
the vehicle's Data Link
Connector (DLC).
The DLC is under the instrument
panel to the left of the steering
wheel. Connecting devices that are
not used to perform an Emissions
Inspection/Maintenance test or to
service the vehicle may affect
vehicle operation. See Add-On
Electrical Equipment 0280. See
your dealer if assistance is needed.
The vehicle may not pass
inspection if:
. The light is on when the engine
is running.
. The light does not come on
when the ignition is in
Service Mode.
. Critical emission control systems
have not been completely
diagnosed. If this happens, the
vehicle would not be ready for
inspection and might require
several days of routine driving

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
138 Instruments and Controls
before the system is ready for
inspection. This can happen if
the 12-volt battery has recently
been replaced or run down, or if
the vehicle has been recently
serviced.
See your dealer if the vehicle will
not pass or cannot be made ready
for the test.
Brake System Warning
Light
MetricEnglish
This light should come on briefly
when the vehicle is turned on. 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 vehicle 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, there is a brake problem.
Have the brake system inspected
right away.
If the light comes on while driving,
pull off the road and stop carefully.
The brake pedal might be harder to
push, or the brake pedal may go
closer to the floor. It could take
longer to stop. If the light is still on,
have the vehicle towed for service.
See
Towing the Vehicle 0363.
{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 warning light should come on
briefly when the vehicle is turned
on. 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,
safely stop as soon as it is possible
and turn off the vehicle. Then turn
on the vehicle again to reset the
system.
If the ABS warning light stays on,
or comes on again while driving, the
vehicle needs service. A chime may
also sound when the light stays on.
If the ABS warning light is the only
light on, the vehicle has regular
brakes, but ABS is not functioning.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Instruments and Controls 139
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
0 138.
Four-Wheel-Drive Light
The four-wheel-drive light comes on
when the 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 0219.
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 0218.
Lane Keep Assist (LKA)
Light
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) 0251.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
140 Instruments and Controls
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.
SeeForward Collision Alert (FCA)
System 0245.
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/ESC
button.
This light and the StabiliTrak/ESC
OFF light come on when StabiliTrak/
Electronic Stability Control (ESC) is
turned off.
If the TCS is off, wheel spin is not
limited. Adjust driving accordingly.
See Traction Control/Electronic
Stability Control 0226.
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/Electronic Stability
Control (ESC) system is turned off.
If StabiliTrak/ESC is off, the Traction
Control System (TCS) is also off.
If StabiliTrak/ESC and TCS are off,
the system does not assist in
controlling the vehicle. Turn on the
TCS and the StabiliTrak/ESC
systems, and the warning light
turns off.
See Traction Control/Electronic
Stability Control 0226.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Instruments and Controls 141
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/
ESC 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/ESC
system is actively working.See
Traction Control/Electronic
Stability Control 0226.
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
(Continued)
Caution (Continued)
engine and it may not be covered
by the vehicle warranty. See
Engine Overheating0300.
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 0300.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
142 Instruments and Controls
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 0333.
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 0336.Engine Oil Pressure Light
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 Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Instruments and Controls 143
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
(Key Access) 036 or
Immobilizer Operation (Keyless
Access) 036.
High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer 0166.
IntelliBeam Light
This light comes on when the
IntelliBeam system, if equipped, is
enabled.
See Exterior Lamp Controls 0164.
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 0169.
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 0164.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
144 Instruments and Controls
Cruise Control Light
The cruise control light is white
when the cruise control is on and
ready, and turns green when the
cruise control is set and active.
SeeCruise Control 0230.
Adaptive Cruise Control Light
This light is white when the Adaptive
Cruise Control (ACC, if equipped) is
on and ready, and turns green when
the ACC is set and active. See
Adaptive Cruise Control 0232.
Door Ajar Light
This light comes on when a door is
open or not securely latched. Before
driving, check that all doors are
properly closed.
Information Displays
Driver Information
Center (DIC)
The DIC displays are shown in the
center of the instrument cluster in
the Info app. See Instrument Cluster
0 126. The displays show the status
of many vehicle systems. The
controls for the DIC are on the right
steering wheel control.
worx: Press to move up or
down in a list.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Instruments and Controls 145
oorp:Press to move between
the interactive display zones in the
cluster.
V: Press to open a menu or select
a menu item. Press and hold to
reset values on certain screens.
DIC Info Page Options
The info pages on the DIC can be
turned on or off through the
Options menu.
1. Press
oto access the cluster
applications.
2. Press
worxto scroll to the
Options application.
3. Press
Vto enter the
Options menu.
4. Scroll to Info Pages and press
p.
5. Press
worxto move
through the list of possible
information displays. 6. Press
Vwhile an item is
highlighted to select or
deselect that item. When an
item is selected, a checkmark
will appear next to it.
DIC Info Pages
The following is the list of all
possible DIC info page displays.
Some may not be available for your
particular vehicle. Some items may
not be turned on by default but can
be turned on through the Options
app. See “DIC Info Page Options”
earlier in this section.
Speed : Shows the vehicle speed in
either kilometers per hour (km/h) or
miles per hour (mph). The vehicle
odometer is also shown on
this page.
Trip A or Trip B, Average Fuel
Economy, and Average Speed :
Shows the current distance traveled,
in either kilometers (km) or
miles (mi), since the trip odometer
was last reset. The Average Fuel Economy display
shows the approximate average
liters per 100 kilometers (L/100 km)
or miles per gallon (mpg). This
number is calculated based on the
number of L/100 km (mpg) recorded
since the last time this menu item
was reset. This number reflects only
the approximate average fuel
economy that the vehicle has right
now, and will change as driving
conditions change.
The Average Speed display shows
the average speed of the vehicle in
kilometers per hour (km/h) or miles
per hour (mph). This average is
calculated based on the various
vehicle speeds recorded since the
last reset of this value.
Press and hold
Vwhile this display
is active to reset the trip odometer,
the average fuel economy, and the
average speed. Or press
pand
select reset in the menu.
Fuel Range and Instantaneous
Fuel Economy : Shows the
approximate distance the vehicle

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Instruments and Controls 149
!:Press to select the display
view. Each press will change the
display view.
D: Lift and hold to brighten the
display. Press and hold to dim the
display. Continue to hold to turn the
display off.
The HUD image will automatically
dim and brighten to compensate for
outside lighting. The HUD
brightness control can also be
adjusted as needed.
The HUD image can temporarily
light up depending on the angle and
position of sunlight on the HUD
display. This is normal.
Polarized sunglasses could make
the HUD image harder to see.
Head-Up Display (HUD) Rotation
Option
This feature allows for adjusting the
angle of the HUD image.
If equipped, this feature allows for
adjusting the angle of the HUD
image. Press
pon the steering
wheel controls while Head-up Display Rotation is highlighted to
enter Adjust Mode. Press
worx
to adjust the angle of the HUD
display. Press
Vto confirm and
save the setting. To cancel the
setting, press
o. The vehicle must
be in P (Park). See Instrument
Cluster 0126.
HUD Views
There are four views in the HUD.
Some vehicle information and
vehicle messages or alerts may be
displayed in any view.
Metric
English
Speed View : This displays digital
speed in English or metric units,
speed limit, vehicle ahead indicator,
Lane Departure Warning/Lane Keep
Assist, and Adaptive Cruise Control
and set speed. Some information
only appears on vehicles that have
these features, and when they are
active.
Metric