GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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258 Driving and Operating
Warning (Continued)
or ice, or if the windshield is
damaged. It may also not detect a
vehicle on winding or hilly roads,
or in conditions that can limit
visibility such as fog, rain,
or snow, or if the headlamps or
windshield are not cleaned or in
proper condition. Keep the
windshield, headlamps, and FCA
sensors clean and in good repair.
Collision Alert
With HUD
Without HUD
When your vehicle approaches
another detected vehicle too rapidly,
the red FCA display will flash on the
windshield. Also, eight rapid
high-pitched beeps will sound from
the front, or both sides of the Safety
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
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 263
If the LCA displays do not light up
when moving vehicles are in the
side blind zone or are 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
0 403.
Lane Departure
Warning (LDW)
If equipped, LDW may help avoid
crashes due to unintentional lane
departures. It may provide a
warning if the vehicle is crossing a
detected lane marking without using
a turn signal in the lane departure
direction. Since this system is part
of the Lane Keep Assist (LKA)
system, read the entire LKA section
before using this feature.
Lane Keep Assist (LKA)
If equipped, LKA may help avoid
crashes due to unintentional lane
departures. It may assist by gently
turning the steering wheel if the
vehicle approaches a detected lane
marking without using a turn signal
in that direction. It may also provide
a Lane Departure Warning (LDW)
system alert as the lane marking is
crossed. The LKA system will not
assist or provide an LDW alert if it
detects that you are actively
steering. Override LKA by turning
the steering wheel. LKA uses a
camera to detect lane markings
between 60 km/h (37 mph) and
180 km/h (112 mph).
{Warning
The LKA system does not
continuously steer the vehicle.
It may not keep the vehicle in the
lane or give a Lane Departure
Warning (LDW) alert, even if a
lane marking is detected.
(Continued)
Warning (Continued)
The LKA and LDW systems
may not:
. Provide an alert or enough
steering assist to avoid a
lane departure or 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.
If LKA only detects lane markings
on one side of the road, it will
only assist or provide an LDW
alert when approaching the lane
on the side where it has detected
a lane marking. Even with LKA
and LDW, you must steer the (Continued)
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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264 Driving and Operating
Warning (Continued)
vehicle. 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 LKA in
bad weather conditions.
{Warning
Using LKA while towing a trailer
or on slippery roads could cause
loss of control of the vehicle and
a crash. Turn the system off.
How the System Works
The LKA camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LKA on and off, press
A
to the left of the steering wheel.When on,
Ais green if LKA is
available to assist and provide LDW
alerts. It may assist by gently
turning the steering wheel and
display
Aas amber if the vehicle
approaches a detected lane marking
without using a turn signal in that
direction. It may also provide an
LDW alert by flashing
Aamber
as the lane marking is crossed.
Additionally, there may be three
beeps, or the driver seat may pulse
three times, on the right or left,
depending on the lane departure
direction.
Take Steering
The LKA system does not
continuously steer the vehicle.
If LKA does not detect active driver
steering, an alert, chime, or DIC
message may be provided. Move
the steering wheel to dismiss.
When the System Does Not
Seem to Work Properly
The system performance may be
affected by:
. Close vehicles ahead.
. Sudden lighting changes, such
as when driving through tunnels.
. Banked roads.
. Roads with poor lane markings,
such as two-lane roads.
If the LKA system is not functioning
properly when lane markings are
clearly visible, cleaning the
windshield may help.
LKA assistance and/or LDW alerts
may occur due to tar marks,
shadows, cracks in the road,
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LKA off if these
conditions continue.
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 271
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing
More passing distance is needed
when towing a trailer. The
combination will not accelerate as
quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making TurnsCaution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a lower
gear before starting down a long or
steep downgrade. If the transmission is not shifted down, the
brakes might get hot and no longer
work well.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
When towing, use the Tow/Haul
Mode to prevent damage to the
engine or transmission. See
Tow/
Haul Mode 0234.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine
off. If the overheat warning comes
on, see Engine Overheating 0302.
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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272 Driving and Operating
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if
facing downhill or into traffic if
facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular
brakes until the chocks absorb
the load.
4. Reapply the brake pedal. Then apply the parking brake and
shift into P (Park). 5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake
pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule 0376.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip. Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
Do not tow a trailer during break-in.
See
New Vehicle Break-In 0217.
Before towing a trailer, see
"Hands-Free Operation" under
Liftgate 044.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too heavy
or the trailer brakes are
inadequate for the load, the
vehicle may not stop as expected.
The driver and passengers could
be seriously injured. The vehicle
may also be damaged; the
resulting repairs would not be
covered by the vehicle warranty.
Pull a trailer only if all the steps in
this section have been followed.
(Continued)
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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278 Driving and Operating
.When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benefit to the
selection of Tow/Haul when the
vehicle is unloaded. Such a
selection when unloaded may result
in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large or
heavy load.
Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for use with electric trailer brakes or
most electric-over-hydraulic trailer
brakes.
This symbol is on the Trailer Brake
Control Panel on vehicles with an
ITBC system. The power output to
the trailer brakes is based on the
amount of brake pressure being
applied by the vehicle’s brake
system, and on the type of trailer
brakes detected. This available
power output to the trailer brakes
can be adjusted to a wide range of
trailering situations.
The ITBC system is integrated with
the vehicle’ s brake, antilock brake,
and StabiliTrak systems. In trailering
conditions that cause the vehicle’s
antilock brake or StabiliTrak
systems to activate, power sent to
the trailer's brakes will be
automatically adjusted to minimize
trailer wheel lock-up. This does not
imply that the trailer has StabiliTrak.
If the vehicle’s brake, antilock brake,
or StabiliTrak systems are not
functioning properly, the ITBC system may not be fully functional
or may not function at all. Make sure
all of these systems are fully
operational to ensure full
functionality of the ITBC system.
The ITBC system is powered
through the vehicle's electrical
system. Turning the ignition off will
also turn off the ITBC system. The
ITBC system is fully functional only
when the ignition is in ON/RUN.
{Warning
Connecting a trailer that has an
air brake system may result in
reduced or complete loss of trailer
braking. There may be an
increase in stopping distance or
trailer instability which could
result in personal injury or
damage to the vehicle, trailer,
or other property. Use the ITBC
system only with electric or
electric over hydraulic trailer
brakes.
GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
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280 Driving and Operating
.A trailer with electric brakes has
become disconnected (a
CHECK TRAILER WIRING
message will also display on
the DIC).
. There is a fault present in the
wiring to the trailer brakes (a
CHECK TRAILER WIRING
message will also display on
the DIC).
. The ITBC system is not working
due to a fault (a SERVICE
TRAILER BRAKE SYSTEM
message will also display in
the DIC).
Manual Trailer Brake Apply
The Manual Trailer Brake Apply
Lever is used to apply the trailer ’s
electric brakes independent of the
vehicle’s brakes. Sliding the lever to
the left will apply only the trailer
brakes. Use this lever to adjust
Trailer Gain to properly adjust the
power output to the trailer brakes.
The trailer's and the vehicle's brake
lamps will come on when either
vehicle brakes or manual trailer
brakes are applied. Trailer Gain Adjustment Procedure
Trailer Gain should be set for a
specific trailering condition and must
be adjusted any time vehicle
loading, trailer loading, or road
surface conditions change.
{Warning
Trailer brakes that are
over-gained or under-gained may
not stop the vehicle and the trailer
as intended and can result in a
crash. Always follow the
instructions to set the Trailer Gain
for the proper trailer stopping
performance.
To adjust Trailer Gain for each
towing condition: 1. Drive the vehicle with the trailer attached on a level road
surface representative of the
towing condition and free of
traffic at about 32 to 40 km/h
(20 to 25 mph) and fully apply
the Manual Trailer Brake apply
lever. Adjusting Trailer Gain at
speeds lower than 32 to
40 km/h (20 to 25 mph) may
result in an incorrect gain
setting.
2. Adjust the Trailer Gain, using the Trailer Gain adjustment
buttons, to just below the point
of trailer wheel lock-up,
indicated by trailer wheel
squeal or tire smoke when a
trailer wheel locks.
Trailer wheel lock-up may not
occur if towing a heavily loaded
trailer. In this case, adjust the
Trailer Gain to the highest
allowable setting for the towing
condition.
3. Readjust Trailer Gain any time vehicle loading, trailer loading,
or road surface conditions
change or if trailer wheel
lock-up is noticed at any time
while towing.
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282 Driving and Operating
A GM dealer may be able to
diagnose and repair problems with
the trailer. However, any diagnosis
and repair of the trailer is not
covered under the vehicle warranty.
Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.
Trailer Sway
Control (TSC)
Vehicles with StabiliTrak have a
Trailer Sway Control (TSC) feature.
Trailer sway is unintended
side-to-side motion of a trailer while
being towed. If the vehicle is towing
a trailer and the TSC detects that
sway is increasing, the vehicle
brakes are selectively applied at
each wheel, to help reduce
excessive trailer sway. If the vehicle
is equipped with the Integrated
Trailer Brake Control (ITBC) system,
and the trailer has the electric
actuated brake system, StabiliTrak
may also apply the trailer brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak
warning light will flash on theinstrument cluster. Vehicle speed
must be reduced. If trailer sway
continues, StabiliTrak can reduce
engine torque to help slow the
vehicle. See
Traction Control/
Electronic Stability Control 0241.
{Warning
Even if the vehicle is equipped
with TSC, trailer sway could result
in loss of control and the vehicle
could crash. If excessive trailer
sway is detected, slow down to a
safe speed. Check the trailer and
vehicle to help correct possible
causes. These could include an
improperly or overloaded trailer,
unrestrained cargo, improper
trailer hitch configuration,
excessive vehicle-trailer speed,
or improperly inflated or incorrect
vehicle or trailer tires. See Towing
Equipment 0275 for trailer ratings
and hitch setup
recommendations. Adding non-dealer accessories can
affect the vehicle performance. See
Accessories and Modifications
0
286.