warning light GMC YUKON XL 2015 Repair Manual

Black plate (22,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-22 Vehicle Care
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove brake fluid,
as necessary, only when work is
done on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system. See“Checking Brake
Fluid” in this section.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5-22. Refer to the Maintenance Schedule
to determine when to check the
brake fluid. See
Maintenance
Schedule on page 11-2.
Checking Brake Fluid
Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview on
page 10-5.
The fluid level should be above
MIN. If it is not, have the brake
hydraulic system checked to see if
there is a leak. After work is done on the brake
hydraulic system, make sure the
level is above MIN but not over the
MAX mark.
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11-12.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it. This
helps keep dirt from entering the
reservoir.
{Warning
With the wrong kind of fluid in the
brake hydraulic system, the
brakes might not work well. This
could cause a crash. Always use
the proper brake fluid.

Black plate (30,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-30 Vehicle Care
Bulb Replacement
For the proper type of replacement
bulbs, seeReplacement Bulbs on
page 10-33.
For any bulb‐changing procedure
not listed in this section, contact
your dealer.
High Intensity Discharge
(HID) Lighting
{Warning
The high intensity discharge
lighting system operates at a very
high voltage. If you try to service
any of the system components,
you could be seriously injured.
Have your dealer or a qualified
technician service them.
After an HID headlamp bulb has
been replaced, the beam might be a
slightly different shade than it was
originally. This is normal.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Headlamps
Driver Side
1. Low-Beam Headlamp
2. High-Beam Headlamp
See your dealer for passenger side
replacement.
Headlamp
1. Open the hood. See Hood on
page 10-4
2. Remove the headlamp bulb assembly cover by turning it
counterclockwise.
3. Turn the bulb socket counterclockwise to remove it
from the headlamp assembly
and pull it straight out.
4. Unplug the electrical connector from the old bulb by releasing
the clip on the bulb socket.
Front Turn Signal Lamps
1. Open the hood. See Hood on
page 10-4
2. Reach in and access the bulb socket from inside the engine
compartment.
3. Turn the bulb socket counterclockwise to remove it
from the headlamp assembly
and pull it straight out.

Black plate (54,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-54 Vehicle Care
Please note that the TPMS is not a
substitute for proper tire
maintenance, and it is the driver's
responsibility to maintain correct tire
pressure, even if under-inflation has
not reached the level to trigger
illumination of the TPMS low tire
pressure telltale.
Your vehicle has also been
equipped with a TPMS malfunction
indicator to indicate when the
system is not operating properly.
The TPMS malfunction indicator is
combined with the low tire pressure
telltale. When the system detects a
malfunction, the telltale will flash for
approximately one minute and then
remain continuously illuminated.
This sequence will continue upon
subsequent vehicle start-ups as
long as the malfunction exists.
When the malfunction indicator is
illuminated, the system may not be
able to detect or signal low tire
pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires orwheels on the vehicle that prevent
the TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow the
TPMS to continue to function
properly.
See
Tire Pressure Monitor
Operation on page 10-54.
See Radio Frequency Statement on
page 13-12.
Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in the tires and transmit the tire
pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.
If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure
shown on the Tire and Loading
Information label. See
Vehicle Load
Limits on page 9-14.
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires are
inflated to the correct inflation
pressure. If the vehicle has DIC

Black plate (55,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
Vehicle Care 10-55
buttons, tire pressure levels can be
viewed. For additional information
and details about the DIC operation
and displays, seeDriver Information
Center (DIC) on page 5-28 andTire
Messages on page 5-40.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
could be an early indicator that the
air pressure is getting low and
needs to be inflated to the proper
pressure.
A Tire and Loading Information label
shows the size of the original
equipment tires and the correct
inflation pressure for the tires when
they are cold. See Vehicle Load
Limits on page 9-14, for an example
of the Tire and Loading Information
label and its location. Also see Tire
Pressure on page 10-51. The TPMS can warn about a low
tire pressure condition but it does
not replace normal tire
maintenance. See
Tire Inspection
on page 10-58, Tire Rotation on
page 10-58 andTires on
page 10-44.
{Caution
Tire sealant materials are not all
the same. A non-approved tire
sealant could damage the TPMS
sensors. TPMS sensor damage
caused by using an incorrect tire
sealant is not covered by the
vehicle warranty. Always use only
the GM approved tire sealant
available through your dealer or
included in the vehicle.
TPMS Malfunction Light and
Message
The TPMS will not function properly
if one or more of the TPMS sensors
are missing or inoperable. When the
system detects a malfunction, the
low tire pressure warning light
flashes for about one minute and
then stays on for the remainder of
the ignition cycle. A DIC warning
message also displays. The
malfunction light and DIC warning
message come on at each ignition
cycle until the problem is corrected.
Some of the conditions that can
cause these to come on are:
.One of the road tires has been
replaced with the spare tire. The
spare tire does not have a
TPMS sensor. The malfunction
light and the DIC message
should go off after the road tire
is replaced and the sensor
matching process is performed
successfully. See "TPMS Sensor
Matching Process" later in this
section.

Black plate (59,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
Vehicle Care 10-59
SeeTire Pressure on
page 10-51 andVehicle Load
Limits on page 9-14.
Reset the Tire Pressure Monitor
System. See Tire Pressure
Monitor Operation on
page 10-54.
Check that all wheel nuts are
properly tightened. See “Wheel
Nut Torque” underCapacities
and Specifications on
page 12-2.
{Warning
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
make wheel nuts become loose
after time. The wheel could come
off and cause an accident. When
changing a wheel, remove any
rust or dirt from places where the
wheel attaches to the vehicle. In
an emergency, a cloth or a paper
(Continued)
Warning (Continued)
towel can be used; however, use
a scraper or wire brush later to
remove all rust or dirt.
Lightly coat the center of the
wheel hub with wheel bearing
grease after a wheel change or
tire rotation to prevent corrosion
or rust build-up. Do not get
grease on the flat wheel
mounting surface or on the
wheel nuts or bolts.
When It Is Time for New
Tires
Factors, such as maintenance,
temperatures, driving speeds,
vehicle loading, and road conditions
affect the wear rate of the tires.
Treadwear indicators are one way to
tell when it is time for new tires.
Treadwear indicators appear when
the tires have only 1.6 mm (1/16 in)
or less of tread remaining. Some
commercial truck tires may not have
treadwear indicators. See Tire
Inspection on page 10-58 andTire
Rotation on page 10-58 for
additional information.
The rubber in tires ages over time.
This also applies to the spare tire,
if the vehicle has one, even if it is
never used. Multiple factors
including temperatures, loading
conditions, and inflation pressure

Black plate (62,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-62 Vehicle Care
low-pressure warning if non-TPC
Spec rated tires are installed.
SeeTire Pressure Monitor
System on page 10-53.
The Tire and Loading
Information label indicates the
original equipment tires on the
vehicle. See Vehicle Load Limits
on page 9-14 for the label
location and more information
about the Tire and Loading
Information label.
Different Size Tires and
Wheels
If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, electronic stability control, or All-Wheel Drive, the performance
of these systems can also be
affected.
{Warning
If different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This
increases the chance of a crash
and serious injury. Only use GM
specific wheel and tire systems
developed for the vehicle, and
have them properly installed by a
GM certified technician.
See Buying New Tires on
page 10-60 andAccessories and
Modifications on page 10-3.
Uniform Tire Quality
Grading
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires by
treadwear, traction, and
temperature performance. This
applies only to vehicles sold in
the United States. The grades
are molded on the sidewalls of
most passenger car tires. The
Uniform Tire Quality Grading
(UTQG) system does not apply
to deep tread, winter tires,
compact spare tires, tires with
nominal rim diameters of
10 to 12 inches (25 to 30 cm),
or to some limited-production
tires.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they

Black plate (64,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-64 Vehicle Care
test wheel than the minimum
required by law. Warning: The
temperature grade for this tire is
established for a tire that is
properly inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire
Balance
The tires and wheels were aligned
and balanced at the factory to
provide the longest tire life and best
overall performance. Adjustments to
wheel alignment and tire balancing
are not necessary on a regular
basis. Consider an alignment check
if there is unusual tire wear or the
vehicle is significantly pulling to one
side or the other. Some slight pull to
the left or right, depending on the
crown of the road and/or other road
surface variations such as troughs
or ruts, is normal. If the vehicle isvibrating when driving on a smooth
road, the tires and wheels may need
to be rebalanced. See your dealer
for proper diagnosis.
Wheel Replacement
Replace any wheel that is bent,
cracked, or badly rusted or
corroded. If wheel nuts keep coming
loose, the wheel, wheel bolts, and
wheel nuts should be replaced.
If the wheel leaks air, replace it.
Some aluminum wheels can be
repaired. See your dealer if any of
these conditions exist.
Your dealer will know the kind of
wheel that is needed.
Each new wheel should have the
same load-carrying capacity,
diameter, width, offset, and be
mounted the same way as the one it
replaces.
Replace wheels, wheel bolts, wheel
nuts, or Tire Pressure Monitor
System (TPMS) sensors with new
GM original equipment parts.
{Warning
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
a crash. Always use the correct
wheel, wheel bolts, and wheel
nuts for replacement.
{Caution
The wrong wheel can also cause
problems with bearing life, brake
cooling, speedometer or
odometer calibration, headlamp
aim, bumper height, vehicle
ground clearance, and tire or tire
chain clearance to the body and
chassis.

Black plate (79,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
Vehicle Care 10-79
{Caution
If any accessories are left on or
plugged in during the jump
starting procedure, they could be
damaged. The repairs would not
be covered by the vehicle
warranty. Whenever possible, turn
off or unplug all accessories on
either vehicle when jump starting.
4. Turn off the ignition on both vehicles. Unplug unnecessary
accessories plugged into the
accessory power outlets. Turn
off the radio and all the lamps
that are not needed. This will
avoid sparks and help save both
batteries. And it could save the
radio! 5. Open the hood on the other
vehicle and locate the
positive (+) and negative (−)
terminal locations on that
vehicle.
The positive (+) terminal is under
a red plastic cover at the positive
battery post. To uncover the
positive (+) terminal, open the
red plastic cover.
For more information on the
location of the remote
positive (+) and remote negative
(−) terminals, see Engine
Compartment Overview on
page 10-5.
{Warning
An electric fan can start up even
when the engine is not running
and can injure you. Keep hands,
clothing and tools away from any
underhood electric fan.
{Warning
Using a match near a battery can
cause battery gas to explode.
People have been hurt doing this,
and some have been blinded.
Use a flashlight if you need more
light.
Battery fluid contains acid that
can burn you. Do not get it on
you. If you accidentally get it in
your eyes or on your skin, flush
the place with water and get
medical help immediately.
{Warning
Fans or other moving engine
parts can injure you badly. Keep
your hands away from moving
parts once the engine is running.

Black plate (86,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-86 Vehicle Care
case into Two-Wheel Drive High.
SeeFour-Wheel Drive on
page 9-37.
8. Turn the ignition to LOCK/OFF.
Four-Wheel Drive Vehicles with a
Two Speed Automatic
Transfer Case
Use the following procedure to dolly
tow a four-wheel drive vehicle from
the rear:
1. Attach the dolly to the tow vehicle following the dolly
manufacturer's instructions.
2. Drive the rear wheels onto the dolly.
3. Firmly set the parking brake. See Parking Brake on
page 9-42.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the manufacturer's
instructions. 6. Use an adequate clamping
device designed for towing to
ensure that the front wheels are
locked into the straight position.
{Warning
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
be injured. Set the parking brake
before shifting the transfer case
to N (Neutral).
7. Shift the transfer case to N (Neutral). See Four-Wheel
Drive on page 9-37.
8. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of
N (Neutral)” underFour-Wheel Drive
on page 9-37.
Appearance Care
Exterior Care
Locks
Locks are lubricated at the factory.
Use a de-icing agent only when
absolutely necessary, and have the
locks greased after using. See
Recommended Fluids and
Lubricants on page 11-12.
Washing the Vehicle
To preserve the vehicle's finish,
wash it often and out of direct
sunlight.
{Caution
Do not use petroleum-based,
acidic, or abrasive cleaning
agents as they can damage the
vehicle's paint, metal, or plastic
parts. If damage occurs, it would
not be covered by the vehicle
warranty. Approved cleaning
(Continued)

Black plate (1,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
INDEX i-1
A
Accessories andModifications . . . . . . . . . . . . . . . . . 10-3
Accessory Power . . . . . . . . . . . . . . 9-27
Active Emergency Braking System . . . . . . . . 1-20, 9-63
Active Fuel Management
®. . . . . 9-30
Adaptive Cruise Control . . . . . . . 9-50
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . . . 9-89
Additional Information
OnStar
®. . . . . . . . . . . . . . . . . . . . . . 14-6
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . . 11-9
Adjustable Throttle and Brake Pedal . . . . . . . . . . . . . . . . . . 9-20
Adjustments Lumbar, Front Seats . . . . . . . . . . . 3-4
Air Cleaner/Filter, Engine . . . . . 10-13
Air Filter, Passenger Compartment . . . . . . . . . . . . . . . . . 8-7
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 8-6 Airbag System
Check . . . . . . . . . . . . . . . . . . . . . . . . 3-41
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . 3-34
Passenger Sensing System . . . . . . . . . . . . . . . . . . . . . . 3-35
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . 3-33
What Will You See after an Airbag Inflates? . . . . . . . . . . . . . 3-34
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . 3-32
Where Are the Airbags? . . . . . . 3-30
Airbags Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . 3-40
Passenger Status Indicator . . . 5-18
Readiness Light . . . . . . . . . . . . . . 5-18
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . 3-40
System Check . . . . . . . . . . . . . . . . 3-28
Alarm Vehicle Security . . . . . . . . . . . . . . 2-24
Alert Lane Change . . . . . . . . . . . . . . . . . 9-66
Side Blind Zone (SBZA) . . . . . . 9-65 All-Season Tires . . . . . . . . . . . . . . 10-45
All-Terrain Tires . . . . . . . . . . . . . . . 10-46
Antilock Brake
System (ABS) . . . . . . . . . . . . . . . . 9-41
Warning Light . . . . . . . . . . . . . . . . . 5-23
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . 10-86
Interior . . . . . . . . . . . . . . . . . . . . . . 10-91
Armrest Storage . . . . . . . . . . . . . . . . 4-2
Assistance Program, Roadside . . . . . . . . . . . . . . . . . . . . . 13-5
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . . 9-61
Assistance Systems for Parking and Backing . . . . . . . . . 9-58
Automatic
Dimming Mirrors . . . . . . . . . . . . . . 2-30
Door Locks . . . . . . . . . . . . . . . . . . . 2-18
Headlamp System . . . . . . . . . . . . . 6-3
Level Control . . . . . . . . . . . . . . . . . 9-47
Transmission . . . . . . . . . . . . . . . . . 9-31
Transmission Fluid . . . . . . . . . 10-10
Automatic Transmission Manual Mode . . . . . . . . . . . . . . . . . 9-34
Shift Lock ControlFunction Check . . . . . . . . . . . 10-27