check engine light GMC YUKON 2020 Owner's Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Introduction 7
21. Data Link Connector (DLC)(Out of View). See Malfunction
Indicator Lamp (Check Engine
Light) 0136.
22. Automatic Transfer Case Knob (If Equipped). See Four-Wheel
Drive 0219.
23. Parking Brake 0225.
24. Exterior Lamp Controls 0164.
Fog Lamps 0169 (If
Equipped).
25. Instrument Panel Illumination
Control 0170.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Keys, Doors, and Windows 13
If two currently recognized keys are
not available, follow this procedure
to program the first key.
This procedure will take
approximately 30 minutes to
complete for the first key. The
vehicle must be off and all of the
keys must be with you.1. Insert the new vehicle key into the ignition.
2. Turn the ignition on without starting the engine. The
security light will come on.
3. Wait 10 minutes until the security light turns off.
4. Turn the ignition off.
5. Repeat Steps 2–4 two more times. After the third time, turn
the ignition on; the key is
learned and all previously
known keys will no longer work
with the vehicle.
6. To learn the second key, turn the ignition off, insert the
second key to be learned, and
turn the ignition on without
starting the engine. After the two keys are learned,
remaining keys can be learned by
following the procedure in
“Programming with Two Recognized
Keys (Key Vehicles Only).”
See your dealer if a replacement
key or additional key is needed.
If locked out of the vehicle, see
Roadside Assistance Program
0
400.
With an active OnStar or connected
service plan, an OnStar Advisor
may remotely unlock the vehicle.
See OnStar Overview 0410.
Remote Keyless Entry
(RKE) System
See Radio Frequency Statement
0 405.
If there is a decrease in the Remote
Keyless Entry (RKE) operating
range:
. Check the distance. The
transmitter may be too far from
the vehicle. .
Check the location. Other
vehicles or objects may be
blocking the signal.
. Check the transmitter's battery.
See “Battery Replacement” later
in this section.
. If the transmitter is still not
working correctly, see your
dealer or a qualified technician
for service.
Remote Keyless Entry
(RKE) System Operation
(Key Access)
The RKE transmitter functions may
work up to 60 m (197 ft) away from
the vehicle.
Other conditions can affect the
performance of the transmitter. See
Remote Keyless Entry (RKE)
System 013.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
36 Keys, Doors, and Windows
Immobilizer
SeeRadio Frequency Statement
0 405.
Immobilizer Operation
(Key Access)
This vehicle has a passive
theft-deterrent system.
The system does not have to be
manually armed or disarmed.
The vehicle is automatically
immobilized when the vehicle is
turned off.
The system is automatically
disarmed when the ignition is turned
from off to on.
The security light, in the instrument
cluster, comes on if there is a
problem with arming or disarming
the theft-deterrent system. When trying to start the vehicle, the
security light comes on briefly when
the ignition is turned on.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the engine still does not start, and
the key appears to be undamaged,
try another ignition key. It may be
necessary to check the fuse. See
Fuses and Circuit Breakers
0315.
If the engine still does not start with
the other key, the vehicle needs
service. If the vehicle does start, the
first key may be faulty. See your
dealer.
It is possible for the immobilizer
system to learn new or replacement
keys. Up to eight keys can be
programmed for the vehicle. To
program additional keys, see Keys
(Keyless Access) 09or
Keys (Key Access) 010. To
program additional transmitters, see
your dealer. Do not leave the key or device that
disarms or deactivates the vehicle
theft system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system.
Immobilizer Operation
(Keyless Access)
This vehicle has a passive
theft-deterrent system.
The system does not have to be
manually armed or disarmed.
The vehicle is automatically
immobilized when the transmitter
leaves the vehicle.
The immobilization system is
disarmed when ENGINE START/
STOP is pressed and a valid
transmitter is found in the vehicle.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Keys, Doors, and Windows 37
The security light in the instrument
cluster comes on when there is a
problem with arming or disarming
the theft-deterrent system.
The system has one or more
transmitters matched to an
immobilizer control unit in your
vehicle. Only a correctly matched
transmitter will start the vehicle.
If the transmitter is ever damaged,
you may not be able to start your
vehicle.
When trying to start the vehicle, the
security light comes on briefly when
the ignition is turned on.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
vehicle off and try again.
If the vehicle will not change ignition
modes (ACC/ACCESSORY, on, off),
and the RKE transmitter appears to
be undamaged, try another
transmitter. Or, you may try placing
the transmitter in the front
cupholder. See“Starting the Vehicle
with a Low Transmitter Battery” under
Remote Keyless Entry (RKE)
System Operation (Key Access)
0 13 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 16.
If the engine does not start with the
other transmitter or when the
transmitter is in the pocket in the
front cupholder, the vehicle needs
service. See your dealer who can
service the theft-deterrent system
and have a new transmitter
programmed to the vehicle.
Do not leave the transmitter or
device that disarms or deactivates
the theft-deterrent system in the
vehicle.Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
114 Instruments and Controls
Instruments and
Controls
Controls
Steering Wheel Adjustment . . . 115
Steering Wheel Controls . . . . . . 116
Heated Steering Wheel . . . . . . . 116
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Windshield Wiper/Washer . . . . 116
Rear Window Wiper/Washer . . . . . . . . . . . . . . . . . . . . . . 118
Compass . . . . . . . . . . . . . . . . . . . . . 119
Clock . . . . . . . . . . . . . . . . . . . . . . . . . 119
Power Outlets . . . . . . . . . . . . . . . . 120
Wireless Charging . . . . . . . . . . . . 122
Warning Lights, Gauges, and
Indicators
Warning Lights, Gauges, and Indicators . . . . . . . . . . . . . . . . . . . 125
Instrument Cluster . . . . . . . . . . . . 126
Speedometer . . . . . . . . . . . . . . . . . 129
Odometer . . . . . . . . . . . . . . . . . . . . . 129
Trip Odometer . . . . . . . . . . . . . . . . 129
Tachometer . . . . . . . . . . . . . . . . . . . 129
Fuel Gauge . . . . . . . . . . . . . . . . . . . 130
Engine Oil Pressure
Gauge . . . . . . . . . . . . . . . . . . . . . . 130 Engine Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 131
Transmission Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 132
Voltmeter Gauge . . . . . . . . . . . . . 133
Seat Belt Reminders . . . . . . . . . 133
Airbag Readiness Light . . . . . . . 134
Passenger Airbag Status
Indicator . . . . . . . . . . . . . . . . . . . . 135
Charging System Light . . . . . . . 135
Malfunction Indicator Lamp (Check Engine Light) . . . . . . . . 136
Brake System Warning Light . . . . . . . . . . . . . . . . . . . . . . . . 138
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . 138
Four-Wheel-Drive Light . . . . . . . 139
Tow/Haul Mode Light . . . . . . . . . 139
Lane Keep Assist (LKA) Light . . . . . . . . . . . . . . . . . . . . . . . . 139
Vehicle Ahead Indicator . . . . . . 140
Traction Off Light . . . . . . . . . . . . . 140
StabiliTrak OFF Light . . . . . . . . . 140
Traction Control System (TCS)/ StabiliTrak Light . . . . . . . . . . . . . 141
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . 141
Tire Pressure Light . . . . . . . . . . . 141
Engine Oil Pressure Light . . . . 142
Low Fuel Warning Light . . . . . . 142 Security Light . . . . . . . . . . . . . . . . . 143
High-Beam On Light . . . . . . . . . . 143
Front Fog Lamp Light . . . . . . . . . 143
Lamps On Reminder . . . . . . . . . 143
Cruise Control Light . . . . . . . . . . 144
Door Ajar Light . . . . . . . . . . . . . . . 144
Information Displays
Driver Information
Center (DIC) . . . . . . . . . . . . . . . . 144
Head-Up Display (HUD) . . . . . . 147
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . 151
Engine Power Messages . . . . . 151
Vehicle Speed Messages . . . . . 152
Vehicle Personalization
Vehicle Personalization . . . . . . . 152
Universal Remote System
Universal Remote System . . . . 160
Universal Remote System Programming . . . . . . . . . . . . . . . 160
Universal Remote System Operation . . . . . . . . . . . . . . . . . . . 163

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Instruments and Controls 125
THIS SOFTWARE IS PROVIDED
BY THE COPYRIGHT HOLDERS
AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED
WARRANTIES OF
MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT
SHALL THE COPYRIGHT HOLDER
OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL,
EXEMPLARY, OR
CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITEDTO, PROCUREMENT OF
SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF
THE USE OF THIS SOFTWARE,
EVEN IF 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-13566587) - 2020 - CRC - 4/15/19
Instruments and Controls 135
Passenger Airbag Status
Indicator
The vehicle has a passenger
sensing system. SeePassenger
Sensing System 080 for important
safety information. The passenger
airbag status indicator is in the
overhead console.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF, or 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, or 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 0134 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 Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
136 Instruments and Controls
system. Have it checked by your
dealer. Driving while this light is on
could drain the battery.
When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a
message.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio
and air conditioner.
Malfunction Indicator
Lamp (Check Engine
Light)
This light is part of the vehicle’s
emission control on-board
diagnostic system. If this light is on
while the engine is running, a
malfunction has been detected and
the vehicle may require service. The
light should come on to show that it
is working when the ignition is in
Service Mode. SeeIgnition
Positions (Keyless Access) 0202 or
Ignition Positions (Key Access)
0 204.
Malfunctions are often indicated by
the system before any problem is
noticeable. Being aware of the light
and seeking service promptly when
it comes on may prevent damage.
Caution
If the vehicle is driven continually
with this light on, the emission
control system may not work as
well, the fuel economy may be
lower, and the vehicle may not
run smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty.
Caution
Modifications to the engine,
transmission, exhaust, intake,
or fuel system, or the use of
replacement tires that do not
meet the original tire
specifications, can cause this light
to come on. This could lead to
costly repairs not covered by the
vehicle warranty. This could also
affect the vehicle’s ability to pass
an Emissions Inspection/
Maintenance test. See
Accessories and Modifications
0283.
If the light is flashing : A
malfunction has been detected that
could damage the emission control
system and increase vehicle
emissions. Diagnosis and service
may be required.
To help prevent damage, reduce
vehicle speed and avoid hard
accelerations and uphill grades.

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
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.