GMC YUKON 2012 Owner's Manual

Black plate (45,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-45
Braking in Emergencies
ABS allows the driver to steer and
brake at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Parking Brake
Set the parking brake by holding the
regular brake pedal down, then
pushing down the parking brake
pedal.If the ignition is on, the brake
system warning light will come on.
See
Brake System Warning Light on
page 5‑23.
Notice: Driving with the parking
brake on can overheat the brake
system and cause premature
wear or damage to brake system
parts. Make sure that the parking
brake is fully released and the
brake warning light is off before
driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the parking brake pedal.
If the parking brake is not released
when you begin to drive, the brake
system warning light will flash and a
chime will sound warning you that
the parking brake is still on.
If you are towing a trailer and are
parking on a hill, see Driving
Characteristics and Towing Tips on
page 9‑68.
Brake Assist
This vehicle has a brake assist
feature designed to assist the driver
in stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement the
power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle. The
stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time is
normal and the driver should
continue to apply the brake pedal as
the driving situation dictates. The
brake assist feature will
automatically disengage when the
brake pedal is released or brake
pedal pressure is quickly
decreased.

Black plate (46,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-46 Driving and Operating
Hill Start Assist (HSA)
Non‐hybrid vehicles with StabiliTrak
have a Hill Start Assist (HSA)
feature, which may be useful when
the vehicle is stopped on a grade.
This feature is designed to prevent
the vehicle from rolling, either
forward or rearward, during vehicle
drive off. After the driver completely
stops and holds the vehicle in a
complete standstill on a grade, HSA
will be automatically activated.
During the transition period between
when the driver releases the brake
pedal and starts to accelerate to
drive off on a grade, HSA holds the
braking pressure for a maximum oftwo seconds to ensure that there is
no rolling. The brakes will
automatically release when the
accelerator pedal is applied within
the two‐second window. If the
vehicle is equipped with the
Integrated Trailer Brake Control
(ITBC) system, HSA may also apply
the trailer brakes. It will not activate
if the vehicle is in a drive gear and
facing downhill or if the vehicle is
facing uphill and in R (Reverse).
There may be situations on minor
hills (less than 5% grade) with a
loaded vehicle or while pulling a
trailer where HSA will not activate.
Ride Control Systems
StabiliTrak®System
The vehicle has a vehicle stability
enhancement system called
StabiliTrak. It is an advanced
computer-controlled system that
assists the driver with directional
control of the vehicle in difficult
driving conditions.
StabiliTrak activates when the
computer senses a discrepancy
between the intended path and the
direction the vehicle is actually
traveling. StabiliTrak selectively
applies braking pressure at any one
of the vehicle's brakes to assist the
driver with keeping the vehicle on
the intended path.

Black plate (47,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-47
StabiliTrak is on automatically
whenever the vehicle is started. To
assist with directional control of the
vehicle, the system should always
be left on. Trailer Sway Control
(TSC) is also on automatically when
the vehicle is started. SeeTrailer
Sway Control (TSC) on page 9‑86
for more information.
When the vehicle is started and
begins to move, the system
performs several diagnostic checks
to insure there are no problems.
The system may be heard or felt
while it is working. This is normal
and does not mean there is a
problem with the vehicle. The
system should initialize before the
vehicle reaches 32 km/h (20 mph).
In some cases, it may take
approximately 3.2 km (2 mi) of
driving before the system initializes. If cruise control is being used when
StabiliTrak activates, the cruise
control automatically disengages.
The cruise control can be
re-engaged when road conditions
allow. See
Cruise Control on
page 9‑51.
If the system fails to turn on or
activate, the StabiliTrak light along
with a message will be displayed on
the Driver Information Center (DIC).
If a DIC message appears, make
sure the StabiliTrak system has not
been turned off using the Traction
Control System (TCS)/StabiliTrak
button. Then turn the vehicle off,
wait 15 seconds, and then turn it
back on again to reset the system.
If any of the messages still appear
on the DIC, the vehicle should be
taken in for service. For more
information on the DIC messages,
see Ride Control System Messages
on page 5‑43.
The StabiliTrak light will flash on the
instrument panel cluster when the
system or the TSC feature is both
on and activated.
The system may be heard or felt
while it is working; this is normal.
The TCS/StabiliTrak button is
located on the instrument panel.
The traction control part of
StabiliTrak can be turned off by
pressing and releasing the TCS/
StabiliTrak button if both systems
(traction control and StabiliTrak)
were previously on.

Black plate (48,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-48 Driving and Operating
To disable both TCS and
StabiliTrak, press and hold the
TCS/StabiliTrak button until the
StabiliTrak OFF light illuminates and
the appropriate DIC message
displays. This will also disable the
TSC feature.
Traction control and StabiliTrak
can be turned on by pressing and
releasing the TCS/StabiliTrak button
if they are not automatically shut off
for any other reason. This will also
enable the TSC feature.
When the TCS or StabiliTrak system
is turned off, the StabiliTrak light
and the appropriate message will be
displayed on the DIC to warn the
driver. The vehicle will still havebrake-traction control when traction
control is off, but will not be able to
use the engine speed management
system. See
“Traction Control
Operation” next for more
information.
When the TCS has been turned off,
system noises may still be heard as
a result of the brake-traction control
coming on.
It is recommended to leave the
system on for normal driving
conditions, but it may be necessary
to turn the system off if the vehicle
is stuck in sand, mud, ice or snow,
and you want to “rock”the vehicle to
attempt to free it. It may also be
necessary to turn off the system
when driving in extreme off-road
conditions where high wheel spin is
required. See If the Vehicle Is Stuck
on page 9‑15.
When the transfer case is in 4LO,
the stability system is automatically
disabled, the StabiliTrak light comes on, and the appropriate message
will appear on the DIC. Both traction
control and StabiliTrak are
automatically disabled in this
condition.Traction Control Operation
The TCS is part of the StabiliTrak
system. Traction control limits wheel
spin by reducing engine power to
the wheels (engine speed
management) and by applying
brakes to each individual wheel
(brake-traction control) as
necessary.
The TCS is enabled automatically
when the vehicle is started. It will
activate and the StabiliTrak light will
flash if it senses that any of the
wheels are spinning or beginning to
lose traction while driving.
If traction control is turned off, only
the brake-traction control portion of
traction control will work. The
engine speed management will be

Black plate (49,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-49
disabled. In this mode, engine
power is not reduced automatically
and the driven wheels can spin
more freely. This can cause the
brake-traction control to activate
constantly.
Notice:If the wheel(s) of one axle
is allowed to spin excessively
while the StabiliTrak
®, ABS, brake
warning lights, and any relevant
DIC messages are displayed, the
transfer case could be damaged.
The repairs would not be covered
by the vehicle warranty. Reduce
engine power and do not spin the
wheel(s) excessively while these
lights and messages are
displayed.
The TCS may activate on dry or
rough roads or under conditions
such as heavy acceleration while
turning or abrupt upshifts/downshifts
of the transmission. When this happens, a reduction in
acceleration may be noticed, or a
noise or vibration may be heard.
This is normal.
If cruise control is being used when
the system activates, the StabiliTrak
light will flash and cruise control will
automatically disengage. Cruise
control may be reengaged when
road conditions allow. See
Cruise
Control on page 9‑51.
StabiliTrak may also turn off
automatically if it determines that a
problem exists with the system.
If the problem does not clear itself
after restarting the vehicle, see your
dealer for service.
Non-hybrid vehicles with StabiliTrak
have a Trailer Sway Control (TSC)
feature. See Trailer Sway Control
(TSC) on page 9‑86. Non-hybrid vehicles with StabiliTrak
have a Hill Start Assist (HSA)
feature. See
Hill Start Assist (HSA)
on page 9‑46.
Adding non‐dealer accessories can
affect the vehicle's performance.
See Accessories and Modifications
on page 10‑3.
Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.

Black plate (50,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-50 Driving and Operating
Continuous Damping
Control (CDC)
This vehicle may have a continuous
damping control system called
Autoride
®or MagneRide™. With
this feature, improved vehicle ride
and handling is provided under a
variety of passenger and loading
conditions.
Autoride and MagneRide are fully
automatic and use a computer
controller to continuously monitor
vehicle speed, wheel to body
position, lift/dive and steering
position of the vehicle. The
controller then sends signals to
each shock absorber to
independently adjust the damping
level to provide the optimum
vehicle ride. Autoride and MagneRide also
interact with the tow/haul mode that,
when activated, will provide
additional control of the shock
absorbers. This additional control
results in better ride and handling
characteristics when the vehicle is
loaded or towing a trailer. See
“Tow/
Haul Mode” underTrailer Towing on
page 9‑72 for more information.
Automatic Level Control
The automatic level control rear
suspension is available on light‐duty
vehicles and comes as a part of the
Continuous Damping Control (CDC)
suspension, if equipped.
This type of level control is fully
automatic and will provide a better
leveled riding position as well as
better handling under a variety of
passenger and loading conditions. An air compressor connected to the
rear shocks will raise or lower the
rear of the vehicle to maintain
proper vehicle height. The system is
activated when the ignition key is
turned to ON/RUN and will
automatically adjust vehicle height
thereafter. The system may exhaust
(lower vehicle height) for up to
ten minutes after the ignition key
has been turned off. You may hear
the air compressor operating when
the height is being adjusted.
If a weight‐distributing hitch is being
used, it is recommended to allow
the shocks to inflate, thereby
leveling the vehicle prior to adjusting
the hitch.

Black plate (51,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-51
Cruise Control
{WARNING
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. So, do not use
the cruise control on winding
roads or in heavy traffic.
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.
With cruise control, a speed of
about 40 km/h (25 mph) or more can
be maintained without keeping your
foot on the accelerator. Cruise
control does not work at speeds
below about 40 km/h (25 mph).
When the brakes are applied, cruise
control is turned off. If the vehicle has StabiliTrak and the
system begins to limit wheel spin,
cruise control will automatically
disengage. See
StabiliTrak
®System
on page 9‑46. When road conditions
allow the cruise control to be safely
used again, it can be turned
back on.
I(On/Off): Press to turn the
system on or off. The indicator light
is on when cruise control is on and
turns off when cruise control is off. +RES (Resume/Accelerate):
Press briefly to make the vehicle
resume to a previously set speed,
or press and hold to accelerate.
SET−
(Set/Coast): Press to set the
speed and activate cruise control or
make the vehicle decelerate.
[(Cancel): Press to disengage
cruise control without erasing the
set speed from memory.
Setting Cruise Control
If the cruise button is on when not in
use, it could get bumped and go into
cruise when not desired. Keep the
cruise control switch off when cruise
is not being used.
The cruise control light on the
instrument panel cluster comes on
after the cruise control has been set
to the desired speed.
1. Press the
Ibutton.
2. Get up to the desired speed.

Black plate (52,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-52 Driving and Operating
3. Press the SET−button located
on the steering wheel and
release it.
4. Take your foot off the accelerator.
Resuming a Set Speed
If the cruise control is set at a
desired speed and then the brakes
are applied, the cruise control is
disengaged without erasing the set
speed from memory.
Once the vehicle speed reaches
about 40 km/h (25 mph) or more,
press the +RES button on the
steering wheel. The vehicle returns
to the previous set speed and stays
there.
Increasing Speed While Using
Cruise Control
If the cruise control system is
already activated,
.Press and hold the +RES button
on the steering wheel until the
desired speed is reached, then
release it.
.To increase vehicle speed in
small amounts, press the +RES
button. Each time this is done,
the vehicle goes about 1.6 km/h
(1 mph) faster.
Reducing Speed While Using
Cruise Control
If the cruise control system is
already activated,
.Press and hold the SET– button
on the steering wheel until the
desired lower speed is reached,
then release it.
.To slow down in small amounts,
press the SET– button on the
steering wheel briefly. Each time
this is done, the vehicle goes
about 1.6 km/h (1 mph) slower.
Passing Another Vehicle While
Using Cruise Control
Use the accelerator pedal to
increase the vehicle speed. When
you take your foot off the pedal, the
vehicle will slow down to the
previous set cruise speed. Using Cruise Control on Hills
How well the cruise control works
on hills depends on the vehicle
speed, the load, and the steepness
of the hills. When going up steep
hills, pressing the accelerator pedal
may be necessary to maintain
vehicle speed.
While going downhill, the Cruise
Grade Braking feature may
automatically shift to a lower gear to
keep the vehicle's speed down.
It may be necessary to apply the
brake or manually shift the
transmission to a lower gear. The
vehicle may shift to a higher gear
when grade braking assistance is
no longer required. Cruise Grade
Braking is not available while in
Range Selection Mode. See "Range
Selection Mode" under
Manual
Mode on page 9‑35.
When the brakes are manually
applied the cruise control is
disengaged.

Black plate (53,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-53
Ending Cruise Control
There are three ways to end cruise
control:
.To disengage cruise control,
step lightly on the brake pedal.
.Press the[on the steering
wheel.
.To turn off the cruise control,
press
Ion the steering wheel.
Erasing Speed Memory
The cruise control set speed is
erased from memory by pressing
the
Ibutton or if the ignition is
turned off.
Object Detection
Systems
Ultrasonic Parking Assist
If available, the Ultrasonic Rear
Parking Assist (URPA) system uses
sensors on the rear bumper to
assist with parking and avoiding
objects while in R (Reverse).
{WARNING
The URPA system does not
detect pedestrians, bicyclists,
animals, or any other objects
located below the bumper or that
are too close or too far from the
vehicle. To prevent injury, death,
or vehicle damage, even with
URPA, always check behind the
vehicle and check all mirrors
before backing.
How the System Works
URPA comes on automatically
when the shift lever is moved into
R (Reverse). A single tone sounds
to indicate the system is working.
URPA operates only at speeds less
than 8 km/h (5 mph).
An obstacle is indicated by
audible beeps. The time between
the beeps gets shorter as the
vehicle approaches the obstacle.
A continuous tone is heard when
the distance is less than
30 cm (12 in).
To be detected, objects must be at
least 25 cm (10 in) off the ground
and below liftgate level. Objects
must also be within 2.5 m (8 ft) from
the rear bumper. This distance may
be less during warmer or humid
weather.

Black plate (54,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-54 Driving and Operating
Turning the System On and Off
Press this button, located next to
the radio, to disable URPA.
The indicator light comes on and
PARK ASSIST OFF displays on the
Driver Information Center (DIC).
SeeObject Detection System
Messages on page 5‑42.
When the System Does Not
Seem to Work Properly
The following messages may be
displayed on the DIC:
SERVICE PARK ASSIST: this
message occurs, take the vehicle to
your dealer for repair. PARK ASSIST OFF:
This message
occurs if the driver disables the
system or if the vehicle is driven
above 8 km/h (5 mph) in
R (Reverse).
PARK ASST BLOCKED SEE
OWNERS MANUAL: This
message can occur under the
following conditions:
.The ultrasonic sensors are not
clean. Keep the rear bumper
free of mud, dirt, snow, ice,
slush, and frost. The message
may not clear until frost or ice
has melted all around and inside
the sensor.
.A trailer is attached to the
vehicle, or a bicycle or an object
hanging out of the liftgate during
the current or last drive cycle.
URPA will return to normal
operation after it is determined
the object is removed. This
could take a few drive cycles.
.A tow bar is attached to the
vehicle. Other conditions may affect system
performance, such as vibrations
from a jackhammer or the
compression of air brakes on a
very large truck.
Side Blind Zone
Alert (SBZA)
If available, the Side Blind Zone
Alert system is a lane changing aid
that assists drivers with avoiding
crashes that occur with vehicles in
the side blind zones.
{WARNING
SBZA does not detect vehicles
rapidly approaching outside of the
side blind zones, pedestrians,
bicyclists, or animals. Failure to
use proper care when changing
lanes may result in injury, death,
or vehicle damage. Always check
for other vehicles and use the
turn signals when changing lanes.