
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
362 Vehicle Care
To dinghy tow:1. Position the vehicle being towed behind the tow vehicle,
facing forward and on a level
surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Apply the parking brake and start the engine.
4. Shift the transfer case to N (Neutral). See “Shifting into
N (Neutral)” underFour-Wheel
Drive 0226. Check that the
vehicle is in N (Neutral) by
starting the engine and shifting
the transmission to
R (Reverse) and then to D
(Drive). There should be no
movement of the vehicle while
shifting.
5. Shift the transmission into D (Drive). Turn the engine off.Caution
Failure to disconnect the negative
battery cable or to have it contact
the terminals can cause damage
to the vehicle.
6. Disconnect the negative battery cable at the battery and
secure the nut and bolt. Cover
the negative battery post with a
non-conductive material to
prevent any contact with the
negative battery terminal.
7. Shift the transmission to P (Park).
Caution
If the steering column is locked,
vehicle damage may occur.
8. Move the steering wheel to make sure the steering column
is unlocked. 9. With a foot on the brake pedal,
release the parking brake.
10. Keep the ignition key in the towed vehicle in ACC/
ACCESSORY to prevent the
steering column from locking.
If equipped with Keyless
Access, keep the RKE
transmitter outside of the
vehicle, and manually lock the
doors. Access the vehicle as if
it has a dead RKE transmitter
battery, by using the key in the
door lock.
Disconnecting the Towed Vehicle
Before disconnecting the towed
vehicle: 1. Park on a level surface.
2. Set the parking brake, then shift the transmission to
P (Park).
3. Connect the battery.
4. Apply the brake pedal.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
382 Service and Maintenance
Battery
The 12-volt battery supplies power
to start the engine and operate any
additional electrical accessories.
.To avoid break-down or failure to
start the vehicle, maintain a
battery with full cranking power.
. Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts
. Belts may need replacing if they
squeak or show signs of
cracking or splitting.
. Trained dealer technicians have
access to tools and equipment
to inspect the belts and
recommend adjustment or
replacement when necessary. Brakes
Brakes stop the vehicle and are
crucial to safe driving.
.
Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
. Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle’s systems
and components. See
Recommended Fluids and
Lubricants 0384 for GM approved
fluids.
. Engine oil and windshield
washer fluid levels should be
checked at every fuel fill.
. Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled. Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks.
With a multi-point inspection, your
dealer can inspect the hoses and
advise if replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.
Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking.
. With a multi-point inspection,
your dealer can check the lamps
and note any concerns.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Customer Information 397
.Lock-Out Service: Service to
unlock the vehicle if you are
locked out. A remote unlock may
be available if you have OnStar.
For security reasons, the driver
must present identification
before this service is given.
. Emergency Tow from a Public
Road or Highway: Tow to the
nearest GMC dealer for warranty
service, or if the vehicle was in a
crash and cannot be driven.
Assistance is not given when the
vehicle is stuck in the sand,
mud, or snow.
. Flat Tire Change: Service to
change a flat tire with the spare
tire. The spare tire, if equipped,
must be in good condition and
properly inflated. It is the owner's
responsibility for the repair or
replacement of the tire if it is not
covered by the warranty.
. Battery Jump Start: Service to
jump start a dead battery. .
Trip Interruption Benefits and
Assistance: If your trip is
interrupted due to a warranty
event, incidental expenses may
be reimbursed within the
Powertrain warranty period.
Items considered are reasonable
and customary hotel, meals,
rental car, or a vehicle being
delivered back to the customer,
up to 500 miles.
Services Not Included in
Roadside Assistance
. Impound towing caused by
violation of any laws
. Legal fines
. Mounting, dismounting,
or changing of snow tires,
chains, or other traction devices
Service is not provided if a vehicle
is in an area that is not accessible
to the service vehicle or is not a
regularly traveled or maintained
public road, which includes ice and
winter roads. Off-road use is not
covered.
Services Specific to
Canadian-Purchased Vehicles
. Fuel Delivery: Reimbursement
is up to 7 L. Diesel fuel delivery
may be restricted. Propane and
other fuels are not provided
through this service.
. Lock-Out Service: Vehicle
registration is required.
. Trip Interruption Benefits and
Assistance: Must be over
150 km from where your trip was
started to qualify.
Pre-authorization, original
detailed receipts, and a copy of
the repair orders are required.
Once authorization has been
received, the Roadside
Assistance advisor will help to
make arrangements and explain
how to receive payment.
. Alternative Service: If
assistance cannot be provided
right away, the Roadside
Assistance advisor may give
permission to get local
emergency road service. You will
receive payment, up to $100,

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
406 OnStar
OnStar
OnStar Overview
OnStar Overview . . . . . . . . . . . . . 406
OnStar Services
Emergency . . . . . . . . . . . . . . . . . . . 407
Security . . . . . . . . . . . . . . . . . . . . . . 408
Navigation . . . . . . . . . . . . . . . . . . . . 408
Connections . . . . . . . . . . . . . . . . . . 409
Diagnostics . . . . . . . . . . . . . . . . . . . 411
OnStar Additional Information
OnStar AdditionalInformation . . . . . . . . . . . . . . . . . . 412
OnStar Overview
=Voice Command Button
QBlue OnStar Button
>Red Emergency Button
This vehicle may be equipped with a
comprehensive, in-vehicle system
that can connect to an OnStar
Advisor for Emergency, Security,
Navigation, Connections, and
Diagnostics Services. OnStar
services may require a paid service
plan and data plan. OnStar requires
the vehicle battery and electrical
system, cellular service, and GPS
satellite signals to be available and
operating. OnStar acts as a link to
existing emergency service
providers. OnStar may collect information about you and your
vehicle, including location
information. See OnStar User
Terms, Privacy Statement, and
Software Terms for more details
including system limitations at
www.onstar.com (U.S.) or
www.onstar.ca (Canada).
The OnStar system status light is
next to the OnStar buttons. If the
status light is:
.
Solid Green: System is ready.
. Flashing Green: On a call.
. Red: Indicates a problem.
. Off: System is active. Press
Q
twice to speak with an OnStar
Advisor.
Press
Qor call 1-888-4ONSTAR
(1-888-466-7827) to speak to an
Advisor.
Functionality of the Voice Command
button may vary by vehicle and
region.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
OnStar 407
Press=to:
. Open the OnStar app on the
infotainment display. See the
infotainment manual for
information on how to use the
OnStar app.
Or
. Make a call, end a call,
or answer an incoming call.
. Give OnStar Hands-Free Calling
voice commands.
. Give OnStar Turn-by-Turn
Navigation voice commands.
. Obtain and customize the Wi-Fi
hotspot name or SSID and
password, if equipped. PressQto connect to an
Advisor to:
. Verify account information or
update contact information.
. Get driving directions.
. Receive a Diagnostic check of
the vehicle's key operating
systems.
. Receive Roadside Assistance.
. Manage Wi-Fi Settings,
if equipped.
Press
>to get a priority connection
to an OnStar Advisor available
24/7 to:
. Get help for an emergency.
. Be a Good Samaritan or
respond to an AMBER Alert.
. Get assistance in severe
weather or other crisis situations
and find evacuation routes.
OnStar Services
Emergency
Emergency Services require an
active, OnStar service plan
(excludes Basic Plan). With
Automatic Crash Response, built-in
sensors can automatically alert a
specially trained OnStar Advisor
who is immediately connected in to
the vehicle to help.
Press
>for a priority connection to
an OnStar Advisor who can contact
emergency service providers, direct
them to your exact location, and
relay important information.
With OnStar Crisis Assist, specially
trained Advisors are available
24 hours a day, 7 days a week, to
provide a central point of contact,
assistance, and information during a
crisis.
With Roadside Assistance, Advisors
can locate a nearby service provider
to help with a flat tire, a battery
jump, or an empty gas tank.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
OnStar 411
3. Say the entire number withoutpausing, including a “1”and the
area code. System responds:
“OK, calling.”
Calling 911 Emergency
1. Press=. System responds:
“OnStar ready.”
2. Say “Call.”System responds:
“Call. Please say the name or
number to call.”
3. Say “911”without pausing.
System responds: “911.”
4. Say “Call.”System responds:
“OK, dialing 911.”
Retrieve My Number
1. Press=. System responds:
“OnStar ready.”
2. Say “My number.” System
responds: “Your OnStar
Hands-Free Calling number is,”
then says the number.
End a Call
Press=. System responds: “Call
ended.”
Verify Minutes and Expiration
Press=and say “Minutes” then
“Verify” to check how many minutes
remain and their expiration date.
Diagnostics
By monitoring and reporting on the
vehicle’s key systems, OnStar
Advanced Diagnostics provides a
way to keep up on maintenance.
Capabilities vary by model. See
www.onstar.com for details and
system limitations. Message and
data rates may apply.
Advanced Diagnostics requires an
active OnStar paid service plan,
e-mail address on file, and
enrollment in Advanced Diagnostics.
Includes:
. Diagnostic Alerts: Set
preferences to receive real-time
e-mails, texts, or monthly
reports of the vehicle’s health.
Or press
Qto have an Advisor
initiate a remote diagnostic
report. .
Proactive Alerts: Receive a
real-time e-mail or text message
regarding potential issues with
key vehicle components, such
as the battery, fuel system,
or starter system. Alerts for
potential issues appear on the
infotainment display. Proactive
Alerts are designed to help
predict specific types of issues
based on information collected
from the vehicle. Other factors
may affect vehicle performance.
Not all issues will deliver alerts.
In some cases, a dealer service
check may be required to
confirm the accuracy of the
alerts.
. Dealer Maintenance Notification:
Have the vehicle notify your
preferred dealer when it is time
for maintenance. Your dealer will
then contact you to set up an
appointment.
To begin, pressQto speak to an
Advisor, or see www.onstar.com.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
414 OnStar
Global Positioning
System (GPS)
.Obstruction of the GPS can
occur in a large city with tall
buildings; in parking garages;
around airports; in tunnels and
underpasses; or in an area with
very dense trees. If GPS signals
are not available, the OnStar
system should still operate to
call OnStar. However, OnStar
could have difficulty identifying
the exact location.
. In emergency situations, OnStar
can use the last stored GPS
location to send to emergency
responders.
A temporary loss of GPS can cause
loss of the ability to send a
Turn-by-Turn Navigation route. The
Advisor may give a verbal route or
may ask for a call back after the
vehicle is driven into an open area.
Cellular and GPS Antennas
Cellular reception is required for
OnStar to send remote signals to
the vehicle. Do not place items over or near the antenna to prevent
blocking cellular and GPS signal
reception.
Unable to Connect to OnStar
Message
If there is limited cellular coverage
or the cellular network has reached
maximum capacity, this message
may come on. Press
Qto try the
call again or try again after driving a
few miles into another cellular area.
Vehicle and Power Issues
OnStar services require a vehicle
electrical system, wireless service,
and GPS satellite technologies to be
available and operating for features
to function properly. These systems
may not operate if the battery is
discharged or disconnected.
Add-on Electrical Equipment
The OnStar system is integrated
into the electrical architecture of the
vehicle. Do not add any electrical
equipment. See Add-On Electrical
Equipment 0279. Added electrical equipment may interfere with the
operation of the OnStar system and
cause it to not operate.
Vehicle Software Updates
OnStar or GM may remotely deliver
software updates or changes to the
vehicle without further notice or
consent. These updates or changes
may enhance or maintain safety,
security, or the operation of the
vehicle or the vehicle systems.
Software updates or changes may
affect or erase data or settings that
are stored in the vehicle, such as
OnStar Hands-Free Calling name
tags, saved navigation destinations,
or pre-set radio stations. Neither
OnStar nor GM is responsible for
any affected or erased data or
settings. These updates or changes
may also collect personal
information. Such collection is
described in the OnStar privacy
statement or separately disclosed at
the time of installation. These
updates or changes may also cause
a system to automatically
communicate with GM servers to
collect information about vehicle

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Index 419
Assistance Program,Roadside . . . . . . . . . . . . . . . . . . . . . . 396
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . . . 250
Assistance Systems for Parking and Backing . . . . . . . . . . 248
Automatic
Dimming Mirrors . . . . . . . . . . . . . . . . 56
Door Locks . . . . . . . . . . . . . . . . . . . . . 44
Forward Braking . . . . . . . . . . . . . . 253
Headlamp System . . . . . . . . . . . . 177
Level Control . . . . . . . . . . . . . . . . . 237
Transmission . . . . . . . . . . . . . . . . . 220
Transmission Fluid . . . . . . 290, 293
Automatic Transmission Manual Mode . . . . . . . . . . . . . . . . . 223
Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 307
Axle, Front . . . . . . . . . . . . . . . . . . . . . . 304
Axle, Rear . . . . . . . . . . . . . . . . . . . . . . 305
B
Battery Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . 182
Load Management . . . . . . . . . . . . 181 Battery (cont'd)
Power Protection . . . . . . . . . . . . . 182
Battery - North America . . . . 303, 356
Blade Replacement, Wiper . . . . . 308
Blind Spot Mirrors . . . . . . . . . . . . . . . 56
Brake Pedal and AdjustableThrottle . . . . . . . . . . . . . . . . . . . . . . 209
System Warning Light . . . . . . . . 148
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . 301 Antilock . . . . . . . . . . . . . . . . . . . . . . . 231
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 233
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Parking . . . . . . . . . . . . . . . . . . . . . . . 232
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 194 Automatic Forward . . . . . . . . . . . 253
Break-In, New Vehicle . . . . . . . . . . 209
Bulb Replacement Back-up Lamps . . . . . . . . . . . . . . . .311
Fog Lamps . . . . . . . . . . . . . . . . . . . .311
Headlamp Aiming . . . . . . . . . . . . . 310
Headlamps . . . . . . . . . . . . . . . . . . . .311
High Intensity Discharge(HID) Lighting . . . . . . . . . . . . . . . .311
License Plate Lamps . . . . . . . . . 312
Buying New Tires . . . . . . . . . . . . . . . 340
C
Calibration . . . . . . . . . . . . . . . . . . . . . . 129
California Fuel Requirements . . . . . . . . . . . 260
Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . 282
California Proposition
65 Warning . . . . . . . . . .281, 303, 356, Back Cover
Canadian Vehicle Owners . . . . . . . . 2
Capacities and Specifications . . . . . . . . . . . . . . . . . 389
Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . 219
Liftgate . . . . . . . . . . . . . . . . . . . . . . . . . 45
Winter Driving . . . . . . . . . . . . . . . . 202
Cargo Tie-Downs . . . . . . . . . . . . . . . . . . . . 123
Caution, Danger, and Warning . . . . 3
Center Console Storage . . . . . . . . 122
Chains, Tire . . . . . . . . . . . . . . . . . . . . 344
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . 132
Charging System Light . . . . . . . . . 145
Check Engine Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . 146