2015 GMC YUKON XL service indicator

Black plate (38,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
9-38 Driving and Operating
ignition is turned on and one will
stay on. If the lights display
momentarily when the ignition is in
ON/RUN, but none stay on, the
knob may have been turned while
the vehicle was off. To see the
indicator, turn the knob to another
position so that it matches the
actual transfer case setting. If no
lights display, take the vehicle to
your dealer for service. An indicator
light flashes while shifting the
transfer case and remains
illuminated when the shift is
complete.
If the transfer case cannot make a
requested shift, it will return to the
last chosen setting. Turn the knob
back to the previous transfer case
setting to see the indicator.
The settings are:
N (Neutral):Use only when the
vehicle needs to be towed. See
Recreational Vehicle Towing on
page 10-81 orTowing the Vehicle
on page 10-81. 2m(Two-Wheel Drive High):
Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy.
AUTO (Automatic Four-Wheel
Drive): Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on
driving conditions. This setting
provides slightly lower fuel economy
than 2
m.
4
m(Four-Wheel Drive High): Use
this position when extra traction is
needed, such as when driving on
snowy or icy roads, when
off-roading, or when plowing snow.
4
n(Four-Wheel Drive Low): This
setting engages the front axle and
delivers extra torque. Choose 4
n
when driving off-road in deep sand,
deep mud, or deep snow, and while
climbing or descending steep hills. Shifting into 4
nwill turn Traction
Control and StabiliTrak off. See
Traction Control/Electronic Stability
Control on page 9-44.
Shifting Into 4
mor AUTO
Turn the knob to the 4
mor AUTO
position at any speed, except from 4
n. The indicator light will flash while
shifting and will remain on when the
shift is completed.
Shifting Into 2
m
Turn the knob to 2mat any speed,
except when shifting from 4
n. The
indicator light will flash while shifting
and will remain on when the shift is
completed.
Shifting Into 4
n
When 4nis engaged, keep vehicle
speed below 72 km/h (45 mph).

Black plate (41,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
Driving and Operating 9-41
indicator, turn the knob to another
position so that it matches the
actual transfer case setting. If no
lights display, take the vehicle to
your dealer for service. An indicator
light flashes while shifting the
transfer case and remains
illuminated when the shift is
complete.
If the transfer case cannot make a
requested shift, it will return to the
last chosen setting. Turn the knob
back to the previous transfer case
setting to see the indicator.
The settings are:
2
m(Two-Wheel Drive High):Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy.
AUTO (Automatic Four-Wheel
Drive): Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on driving conditions. This setting
provides slightly lower fuel economy
than 2
m.
4
m(Four-Wheel Drive High): Use
this position when extra traction is
needed, such as when driving on
snowy or icy roads, when
off-roading, or when plowing snow.
Shifting Into 4
mor AUTO
Turn the knob to the 4
mor AUTO
position. This can be done at any
speed. The indicator light will flash
while shifting. It will remain on when
the shift is completed.
Shifting Into 2
m
Turn the knob to the 2mposition.
This can be done at any speed. The
indicator light will flash while
shifting. It will remain on when the
shift is completed.
Brakes
Antilock Brake
System (ABS)
This vehicle has ABS, an advanced
electronic braking system that helps
prevent a braking skid.
When the vehicle begins to drive
away, ABS checks itself.
A momentary motor or clicking noise
might be heard while this test is
going on, and it might even be
noticed that the brake pedal moves
a little. This is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
on page 5-23.

Black plate (63,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
Driving and Operating 9-63
Alert Seat will pulse five times.
When this Collision Alert occurs, the
brake system may prepare for driver
braking to occur more rapidly which
can cause a brief, mild deceleration.
Continue to apply the brake pedal
as needed. Cruise control may be
disengaged when the Collision Alert
occurs.
Tailgating Alert
The vehicle-ahead indicator will
display amber when you are
following a vehicle ahead much too
closely.
Selecting the Alert Timing
The Collision Alert control is on the
steering wheel. Press
[/3to
set the FCA timing to Far, Medium,
Near, or on some vehicles, Off. The
first button press shows the current setting on the DIC. Additional button
presses will change this setting. The
chosen setting will remain until it is
changed and will affect the timing of
both the Collision Alert and the
Tailgating Alert features. The timing
of both alerts will vary based on
vehicle speed. The faster the
vehicle speed, the farther away the
alert will occur. Consider traffic and
weather conditions when selecting
the alert timing. The range of
selectable alert timing may not be
appropriate for all drivers and
driving conditions.
If your vehicle is equipped with
Adaptive Cruise Control (ACC),
changing the FCA timing setting
automatically changes the ACC
following gap setting (Far, Medium,
or Near).
Unnecessary Alerts
FCA may provide unnecessary
alerts for turning vehicles, vehicles
in other lanes, objects that are not
vehicles, or shadows. These alerts
are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to
operate properly, cleaning the
outside of the windshield in front of
the camera sensor behind the
rearview mirror, and cleaning the
front of the vehicle where radar
sensors are located, may correct
the issue.
For cleaning instructions, see
“Washing the Vehicle”
under
Exterior Care on page 10-86.
System operation may also be
limited under snow, heavy rain,
or road spray conditions.
Active Emergency
Braking System
If the vehicle has Adaptive Cruise
Control (ACC) it also has the Active
Emergency Braking System, which
includes Intelligent Brake
Assist (IBA) and the Automatic

Black plate (68,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
9-68 Driving and Operating
after cleaning both sides of the
vehicle toward the rear corners of
the vehicle, see your dealer.
If the LCA displays do not light up
when vehicles are in the side blind
zone or rapidly approaching this
zone and the system is clean, the
system may need service. Take the
vehicle to your dealer.
When LCA is disabled for any
reason other than the driver turning
it off, the Side Blind Zone Alert On
option will not be available on the
personalization menu.
Radio Frequency Information
SeeRadio Frequency Statement on
page 13-12.
Lane Departure
Warning (LDW)
If equipped, LDW may help avoid
crashes due to unintentional lane
departures. It may provide an alert if
the vehicle is crossing a lane
without using a turn signal in that
direction. LDW uses a camera sensor to detect the lane markings
at speeds of 56 km/h (35 mph) or
greater.
{Warning
The LDW system does not steer
the vehicle. The LDW system
may not:
.Provide enough time to avoid
a crash.
.Detect lane markings under
poor weather or visibility
conditions. This can occur if
the windshield or headlamps
are blocked by dirt, snow,
or ice; if they are not in
proper condition; or if the sun
shines directly into the
camera.
.Detect road edges.
.Detect lanes on winding or
hilly roads.
(Continued)
Warning (Continued)
If LDW only detects lane
markings on one side of the road,
it will only warn you when
departing the lane on the side
where it has detected a lane
marking. Always keep your
attention on the road and
maintain proper vehicle position
within the lane, or vehicle
damage, injury, or death could
occur. Always keep the
windshield, headlamps, and
camera sensors clean and in
good repair. Do not use LDW in
bad weather conditions.
How the System Works
The LDW camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LDW on and off, press
@to
the left of the steering wheel. The
control indicator will light when LDW
is on.

Black plate (70,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
9-70 Driving and Operating
If the vehicle has a yellow fuel cap,
E85 or FlexFuel can be used in the
vehicle. SeeE85 or FlexFuel on
page 9-71.
Use regular unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 87 or
higher. Do not use gasoline with an
octane rating below 87, as it may
cause engine damage and will lower
fuel economy.
Use of Seasonal Fuels
Use summer and winter fuels in the
appropriate season. The fuels
industry automatically modifies the
fuel for the appropriate season.
If fuel is left in the vehicle tank for
long periods of time, driving or
starting could be affected. Drive the
vehicle until the fuel is at one-half
tank or less, then refuel with the
current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates
such as ethers and ethanol, as well
as reformulated gasolines, are available in some cities. If these
gasolines comply with the
previously described specification,
then they are acceptable to use.
However, E85 (85% ethanol) and
other fuels containing more than
15% ethanol must be used only in
FlexFuel vehicles.
{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Some gasolines, mainly high octane
racing gasolines, can contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use
gasolines and/or fuel additives with
MMT as they can reduce spark plug
life and affect emission control
system performance. The malfunction indicator lamp may turn
on. If this occurs, see your dealer
for service.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control
label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle may not pass a smog-check
test. See
Malfunction Indicator
Lamp on page 5-20. If this occurs,
return to your authorized dealer for
diagnosis. If it is determined that the
condition is caused by the type of
fuel used, repairs may not be
covered by the vehicle warranty.

Black plate (83,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
Driving and Operating 9-83
Since the vehicle is equipped with
StabiliTrak, the trailer brakes cannot
tap into the vehicle's hydraulic
system.
Trailer Wiring Harness
The seven-pin trailer connector is
mounted in the bumper. This
connector can be plugged into a
seven-pin universal heavy-duty
trailer connector available through
your dealer.
The seven-wire harness contains
the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Green/Violet: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red/Green: Battery Feed
.Dark Blue: Trailer Brake
If charging a remote (non-vehicle)
battery, press the Tow/Haul mode
button at the end of the shift lever. This will boost the vehicle system
voltage and properly charge the
battery. If the trailer is too light for
Tow/Haul mode, turn on the
headlamps as a second way to
boost the vehicle system and
charge the battery.
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part of
the trailer wiring package. These
provisions are for an electric brake
controller.
The harness should be installed by
your dealer or a qualified service
center.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.
This indicator light on the instrument
cluster comes on when the Tow/
Haul Mode is on.

Black plate (18,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-18 Vehicle Care
{Caution
If the pressure cap is not tightly
installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
{Caution
Running the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty.
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge in the vehicle's instrument
cluster. See Engine Coolant
Temperature Gauge on page 5-16. In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC). See
Engine Cooling System Messages
on page 5-33
andEngine Power
Messages on page 5-35.
If the decision is made not to lift the
hood when this warning appears,
get service help right away.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Check to see if the engine cooling
fan(s) are running. If the engine is
overheating, the fans should be
running. If they are not, do not
continue to run the engine and have
the vehicle serviced.
If Steam is Coming from the
Engine Compartment
{Warning
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Just turn it
off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
engine if it overheats, and get out
of the vehicle until the engine
is cool.

Black plate (20,1)GMC 2015i Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431503) - 2015 - crc - 8/11/14
10-20 Vehicle Care
fans will change to low speed when
additional cooling is no longer
required.
The electric engine cooling fans
may run after the engine has been
turned. off. This is normal and no
service is required.
Washer Fluid
What to Use
When windshield washer fluid needs
to be added, be sure to read the
manufacturer's instructions before
use. Use a fluid that has sufficient
protection against freezing in an
area where the temperature may fall
below freezing.
Adding Washer Fluid
The vehicle has a low washer fluid
message on the DIC that comes on
when the washer fluid is low. The
message is displayed for
15 seconds at the start of each
ignition cycle. When the WASHER
FLUID LOW ADD FLUID messagedisplays, washer fluid will need to
be added to the windshield washer
fluid reservoir.
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See
Engine
Compartment Overview on
page 10-5 for reservoir location.
{Caution
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
(Continued)
Caution (Continued)
to freeze and damage the
washer fluid tank and other
parts of the washer system.
.When using concentrated
washer fluid, follow the
manufacturer instructions for
adding water.
.Fill the washer fluid tank only
three-quarters full when it is
very cold. This allows for fluid
expansion if freezing occurs,
which could damage the tank
if it is completely full.
Brakes
Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time when the vehicle
is moving, except when applying the
brake pedal firmly.