2021 GMC YUKON warning lights

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
44 Seats and Restraints
Obstructions
If something has blocked the driver seat
while recalling a memory position, the recall
may stop. Remove the obstruction and try
the recall again. If the memory position still
does not recall, see your dealer.
Heated and Ventilated Front
Seats
{Warning
If temperature change or pain to the skin
cannot be felt, the seat heater may cause
burns. To reduce the risk of burns, use
care when using the seat heater,
especially for long periods of time. Do
not place anything on the seat that
insulates against heat, such as a blanket,
cushion, cover, or similar item. This may
cause the seat heater to overheat. An
overheated seat heater may cause a burn
or may damage the seat.Heated and Ventilated Seat Buttons Shown,Heated Seat Buttons Similar
If equipped, the buttons are near the
climate controls on the center stack. To
operate, the engine must be on.
Press
Ior+to heat the driver or
passenger seatback.
Press
Jorzto heat the driver or
passenger seatback and cushion.
Press
Cor{, if available, to ventilate the
driver or passenger seat. A ventilated seat
has a fan that pulls or pushes air through
the seat. The air is not cooled. When this feature is off, the heated and
ventilated seat symbols on the buttons are
white. When a heated seat is turned on, the
symbol turns red. When a ventilated seat is
turned on, the symbol turns blue.
Press the button once for the highest
setting. With each press of the button, the
seat will change to the next lower setting,
and then to the off setting. The indicator
lights next to the buttons indicate three for
the highest setting and one for the lowest.
If the heated seats are on high, the level
may automatically be lowered after
approximately 30 minutes.
The passenger seat may take longer to
heat up.
Auto Heated and Ventilated Seats
When the vehicle is on, this feature will
automatically activate the heated or
ventilated seats at the level required by the
vehicle’s interior temperature.
The active high, medium, low, or off heated
or ventilated seat level will be indicated by
the manual heated or ventilated seat
buttons on the center stack. Use the manual
heated or ventilated seat buttons on the
center stack to turn auto heated or
ventilated seats off. If the passenger seat is

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Seats and Restraints 45
unoccupied, the auto heated or ventilated
seats feature will not activate that seat. The
auto heated or ventilated seats feature can
be programmed to always be enabled when
the vehicle is on.
SeeVehicle Personalization 0126.
Remote Start Heated and Ventilated Seats
During a remote start, the heated or
ventilated seats, if equipped, can be turned
on automatically. When it is cold outside,
the heated seats turn on, and when it is hot
outside the ventilated seats turn on. If the
auto heated or ventilated seats feature,
if equipped, is not turned on, the heated or
ventilated seats may be canceled when the
ignition is turned on. If necessary, press the
heated or ventilated seat button to use the
heated or ventilated seats after the vehicle
is started.
The heated or ventilated seat indicator lights
may turn on during a remote start.
The temperature performance of an
unoccupied seat may be reduced. This is
normal. The remote start heated or ventilated seats
may be enabled or disabled in the vehicle
personalization menu. See
Remote Vehicle
Start 014 and
Vehicle Personalization 0126.
Rear Seats
Rear Seat Reminder
If equipped, the message REAR SEAT
REMINDER LOOK IN REAR SEAT displays
under certain conditions indicating there
may be an item or passenger in the rear
seat. Check before exiting the vehicle.
This feature will activate when a second row
door is opened while the vehicle is on or up
to 10 minutes before the vehicle is turned
on. There will be an alert when the vehicle
is turned off. The alert does not directly
detect objects in the rear seat; instead,
under certain conditions, it detects when a
rear door is opened and closed, indicating
that there may be something in the
rear seat.
The feature is active only once each time
the vehicle is turned on and off, and will
require reactivation by opening and closing
the second row doors. There may be an
alert even when there is nothing in the rear seat; for example, if a child entered the
vehicle through the rear door and left the
vehicle without the vehicle being shut off.
The feature can be turned on or off. See
Vehicle Personalization
0126.
Heated Rear Seats
{Warning
If temperature change or pain to the skin
cannot be felt, the seat heater may cause
burns. See the Warning under Heated
and Ventilated Front Seats 044.
The buttons are on the rear of the center
console.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Instruments and Controls 95
Instruments and Controls
Controls
Steering Wheel Adjustment . . . . . . . . . . . . 96
Steering Wheel Controls . . . . . . . . . . . . . . . 96
Heated Steering Wheel . . . . . . . . . . . . . . . . . 96
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Windshield Wiper/Washer . . . . . . . . . . . . . . 97
Rear Window Wiper/Washer . . . . . . . . . . . 98
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Power Outlets . . . . . . . . . . . . . . . . . . . . . . . . . 100
Wireless Charging . . . . . . . . . . . . . . . . . . . . . 101
Warning Lights, Gauges, and Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Instrument Cluster . . . . . . . . . . . . . . . . . . . . 104
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . 106
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Fuel Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Engine Oil Pressure Gauge . . . . . . . . . . . . . 107
Engine Coolant Temperature Gauge . . . 108
Voltmeter Gauge . . . . . . . . . . . . . . . . . . . . . . 108
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . 109
Airbag Readiness Light . . . . . . . . . . . . . . . . 109
Passenger Airbag Status Indicator . . . . . . 110
Charging System Light . . . . . . . . . . . . . . . . . 111 Malfunction Indicator Lamp (Check
Engine Light) . . . . . . . . . . . . . . . . . . . . . . . . . 111
Brake System Warning Light . . . . . . . . . . . 112
Electric Parking Brake Light . . . . . . . . . . . . 113
Service Electric Parking Brake Light . . . . . 113
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . 114
Hill Descent Control Light . . . . . . . . . . . . . . 114
Lane Keep Assist (LKA) Light . . . . . . . . . . . 114
Vehicle Ahead Indicator . . . . . . . . . . . . . . . . 115
Pedestrian Ahead Indicator . . . . . . . . . . . . . 115
Traction Off Light . . . . . . . . . . . . . . . . . . . . . . 115
Traction Control System (TCS)/Electronic Stability Control Light . . . . . . . . . . . . . . . . 115
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Driver Mode Control Light . . . . . . . . . . . . . 116
Four Corner Air Suspension Light . . . . . . . 117
Tire Pressure Light . . . . . . . . . . . . . . . . . . . . . 118
Engine Oil Pressure Light . . . . . . . . . . . . . . 118
Low Fuel Warning Light . . . . . . . . . . . . . . . . 118
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . 119
High-Beam On Light . . . . . . . . . . . . . . . . . . . 119
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . 119
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 119
Cruise Control Light . . . . . . . . . . . . . . . . . . . . 119
Door Ajar Light . . . . . . . . . . . . . . . . . . . . . . . . 120
Information Displays
Driver Information Center (DIC) . . . . . . . . 120
Head-Up Display (HUD) . . . . . . . . . . . . . . . . 122
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . . . . . . . . . . . 125
Engine Power Messages . . . . . . . . . . . . . . . 125
Vehicle Speed Messages . . . . . . . . . . . . . . . 126
Vehicle Personalization
Vehicle Personalization . . . . . . . . . . . . . . . . 126
Universal Remote System
Universal Remote System . . . . . . . . . . . . . . 131
Universal Remote System Programming . . . . . . . . . . . . . . . . . . . . . . . . . 131
Universal Remote System Operation . . . 133

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Instruments and Controls 103
OSS Notice Information
To obtain the source code that is contained
in this product, please visit http://
opensource.lge.com. In addition to the
source code, all referred license terms,
warranty disclaimers and copyright notices
are available for download. LG Electronics
will also provide open source code to you
on CD-ROM for a charge covering the cost of
performing such distribution (such as the
cost of media, shipping, and handling) upon
email request to [email protected]. This
offer is valid for three (3) years from the
date on which you purchased the product.
Freescale-WCT library
Copyright (c) 2012-2014 Freescale
Semiconductor, Inc.. All rights reserved.1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following
disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following
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specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE
COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED
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ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.Warning Lights, Gauges, and
Indicators
Warning lights and gauges can signal that
something is wrong before it becomes
serious enough to cause an expensive repair
or replacement. Paying attention to the
warning lights and gauges could prevent
injury.
Some warning lights come on briefly when
the engine is started to indicate they are
working. When one of the warning lights
comes on and stays on while driving,
or when one of the gauges shows there
may be a problem, check the section that
explains what to do. Waiting to do repairs
can be costly and even dangerous.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
110 Instruments and Controls
pretensioners, the airbag modules, the
wiring, and the crash sensing and diagnostic
module. For more information on the airbag
system, seeAirbag System 060.
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.
Passenger Airbag Status Indicator
The vehicle has a passenger sensing system.
See Passenger Sensing System 066 for
important safety information. The overhead
console has a passenger airbag status
indicator.
United States and Canada
When the vehicle is started, the passenger
airbag status indicator will light ON and OFF,
and the symbols 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, and the symbol
for on or off, to let you know the status of
the front outboard passenger frontal airbag.
If the word ON, and the on symbol, are lit
on the passenger airbag status indicator, it
means that the front outboard passenger
frontal airbag is allowed to inflate. If the word OFF, and the off symbol, are lit
on the passenger 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, if there are no
lights at all, or if the airbag readiness light
is on, there may be a problem with the
lights or the passenger sensing system. See
your dealer for service right away.{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. See
Airbag Readiness Light 0109
for more information, including important
safety information.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
134 Lighting
Lighting
Exterior Lighting
Exterior Lamp Controls . . . . . . . . . . . . . . . . 134
Exterior Lamps Off Reminder . . . . . . . . . . 136
Headlamp High/Low-Beam Changer . . . 136
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Daytime Running Lamps (DRL) . . . . . . . . . 136
Automatic Headlamp System . . . . . . . . . . 136
Hazard Warning Flashers . . . . . . . . . . . . . . 137
Turn and Lane-Change Signals . . . . . . . . . 138
Fog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Interior Lighting
Instrument Panel IlluminationControl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Reading Lamps . . . . . . . . . . . . . . . . . . . . . . . . 139
Lighting Features
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . 140
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Battery Load Management . . . . . . . . . . . . 140
Battery Power Protection . . . . . . . . . . . . . . 141
Exterior Lighting Battery Saver . . . . . . . . . 141
Exterior Lighting
Exterior Lamp Controls
The exterior lamp control is on the
instrument panel to the left of the steering
wheel.
There are four positions:
O: Turns off the automatic headlamps and
Daytime Running Lamps (DRL). Turn the
headlamp control to
Oagain to turn the
automatic headlamps or DRL back on.
For vehicles first sold in Canada, the off
position will only work when the vehicle is
shifted into P (Park). AUTO :
Automatically turns on the
headlamps, parking lamps, taillamps,
instrument panel lights, roof marker lamps
(if equipped), and license plate lamps.
;: Turns on the parking lamps including
all lamps, except the headlamps.
2: Turns on the headlamps with the
parking lamps and instrument panel lights.
When the headlamps are turned on while
the vehicle is on, the headlamps turn off
automatically 10 minutes after the ignition
is turned off. When the headlamps are
turned on while the vehicle is off, the
headlamps will stay on for 10 minutes
before turning off to prevent the battery
from being drained. Turn the headlamp
control off and then back to the headlamp
on position to make the headlamps stay on
for an additional 10 minutes.
To keep the lamps on for more than
10 minutes, the ignition must be on or in
ACC/ACCESSORY.
IntelliBeam System
If equipped, this system turns the vehicle's
high-beam headlamps on and off according
to surrounding traffic conditions.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Lighting 137
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 instrumentpanel brightness control is in the full bright
position. See
Instrument Panel Illumination
Control 0139.
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 to
Oor 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
Oor;to disable
this feature.
Hazard Warning Flashers
Yukon/Yukon XL is shown, Denali similar
|: 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 Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Driving and Operating 227
interference to the Keyless Access system.
SeeRemote Keyless Entry (RKE) System
Operation 08.
To shift out of P (Park), the ignition must be
on or in Service Mode, and the brake pedal
must be applied.
{Warning
Turning off the vehicle while moving may
cause loss of power assist in the brake
and steering systems and disable the
airbags. While driving, only shut the
vehicle off in an emergency.
Stopping the Engine/LOCK/OFF (No Indicator
Lights) : When the vehicle is stopped, press
ENGINE START/STOP once to turn the
engine off.
If the vehicle is in P (Park), the ignition will
turn off, and Retained Accessory Power (RAP)
will remain active. See Retained Accessory
Power (RAP) 0229.
If the vehicle is not in P (Park), the ignition
will return to ACC/ACCESSORY and display
the message SHIFT TO PARK in the Driver
Information Center (DIC). When the vehicle is
shifted into P (Park), the ignition system will
turn off. The vehicle may have an electric steering
column lock. The lock is activated when the
ignition is turned off and either front door is
opened. A sound may be heard as the lock
actuates or releases. The steering column
lock may not release with the wheels turned
off center. If this happens, the vehicle may
not start. Move the steering wheel from left
to right while attempting to start the
vehicle. If this does not work, the vehicle
needs service.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady pressure. Do not pump the brakes repeatedly. This
may deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the vehicle is moving.
After shifting to N (Neutral), firmly apply
the brakes and steer the vehicle to a
safe location.
3. Come to a complete stop. Hold the brake pedal down and shift to P (Park). The
vehicle must be in P (Park) to turn the
ignition off.
4. Continue to hold the brake pedal down. 5. Set the parking brake. See
Electric
Parking Brake 0240.
6. Press ENGINE START/STOP once to turn the ignition off.
7. Release the brake pedal.
If the vehicle cannot be pulled over, and
must be shut off while driving, press and
hold ENGINE START/STOP for longer than
two seconds, or press twice in five seconds.
ACC/ACCESSORY (Amber Indicator Light) :
This mode allows some electrical accessories
to be used when the engine is off.
With the ignition off, pressing the button
one time without the brake pedal applied
will place the ignition system in ACC/
ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to off after five minutes to
prevent battery rundown.
ON/RUN/START (Green Indicator Light) : This
mode is for driving and starting. With the
ignition off, and the brake pedal applied,
pressing the button once will turn the
ignition on. Once engine cranking begins,
release the button. Engine cranking will
continue until the engine starts. See Starting
the Engine 0228.