2009 GMC YUKON ECO mode

Problem Recommended Action
No power. The ignition might not be
turned ON/RUN or in
ACC/ACCESSORY.
The picture does not
ll the screen. There
are black borders on
the top and bottom or
on both sides or it looks
stretched out.Check the display mode
settings in the setup menu
by pressing the display
menu button on the
remote control.
In auxiliary mode, the
picture moves or scrolls.Check the auxiliary input
connections at both
devices.
The remote control does
not work.Check to make sure there
is no obstruction between
the remote control and the
transmitter window.
Check the batteries to
make sure they are not
dead or installed
incorrectly.
After stopping the player,
I push Play but sometimes
the DVD starts where I left
off and sometimes at the
beginning.If the stop button was
pressed one time, the DVD
player resumes playing
where the DVD was
stopped. If the stop button
was pressed two times the
DVD player begins to play
from the beginning of
the DVD.Problem Recommended Action
The auxiliary source is
running but there is no
picture or sound.Check that the RSE video
screen is in the auxiliary
source mode.
Check the auxiliary input
connections at both
devices.
Sometimes the wireless
headphone audio cuts out
or buzzes.Check for obstructions,
low batteries, reception
range, and interference
from cellular telephone
towers or by using a
cellular telephone in the
vehicle.
Check that the
headphones are on
correctly using the L (left)
and R (right) on the
headphones.
I lost the remote and/or
the headphones.See your dealer/retailer
for assistance.
The DVD is playing, but
there is no picture or
sound.Check that the RSE video
screen is sourced to the
DVD player.
3-133

Braking
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
SeeBrake System Warning Light on page 3-40.
Braking action involves perception time and reaction
time. Deciding to push the brake pedal is perception
time. Actually doing it is reaction time.
Average reaction time is about three-fourths of a
second. But that is only an average. It might be less
with one driver and as long as two or three seconds or
more with another. Age, physical condition, alertness,
coordination, and eyesight all play a part. So do alcohol,
drugs, and frustration. But even in three-fourths of a
second, a vehicle moving at 60 mph (100 km/h) travels
66 feet (20 m). That could be a lot of distance in an
emergency, so keeping enough space between
the vehicle and others is important.
And, of course, actual stopping distances vary greatly
with the surface of the road, whether it is pavement or
gravel; the condition of the road, whether it is wet, dry, or
icy; tire tread; the condition of the brakes; the weight of
the vehicle; and the amount of brake force applied.Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This
is a mistake. The brakes might not have time to
cool between hard stops. The brakes will wear out
much faster with a lot of heavy braking. Keeping pace
with the traffic and allowing realistic following distances
eliminates a lot of unnecessary braking. That means
better braking and longer brake life.
If the engine ever stops while the vehicle is being
driven, brake normally but do not pump the brakes.
If the brakes are pumped, the pedal could get harder
to push down. If the engine stops, there will still be some
power brake assist but it will be used when the brake
is applied. Once the power assist is used up, it can
take longer to stop and the brake pedal will be harder
to push.
Adding non-dealer/non-retailer accessories can affect
vehicle performance. SeeAccessories and Modifications
on page 5-3.
4-4

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. SeeIf Your Vehicle is Stuck in
Sand, Mud, Ice, or Snow on page 4-31
Traction Control Operation
The traction control system 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 traction control system is enabled automatically
when the vehicle is started. It will activate and the
StabiliTrak light will ash 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 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 and 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 traction control system 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 ash and cruise control will
automatically disengage. Cruise control may be
reengaged when road conditions allow. SeeCruise
Control on page 3-12
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/retailer for service.
4-8

Level Control
Automatic Level Control
The automatic level control rear suspension is available
on light-duty vehicles and comes as a part of the
Autoride
®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 inate, thereby
leveling the vehicle prior to adjusting the hitch.
Autoride®
With this feature, improved vehicle ride and handling is
provided under a variety of passenger and loading
conditions.
The system is fully automatic and uses 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 also interacts 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”
underTowing a Trailer on page 4-52for more
information.
4-51

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 panel cluster
comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. SeeTow/Haul Mode
on page 2-35for more information.Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75 percent
of the vehicle’s Gross Combined Weight Rating (GCWR).
See “Weight of the Trailer” earlier in the section. Tow/
Haul is most useful under the following driving conditions:
When pulling a heavy trailer or a large or heavy load
through rolling terrain.
When pulling a heavy trailer or a large or heavy load
in stop and go traffic.
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 benet 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.
4-60

Heavy-Duty Trailer Wiring Harness
Package
The vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven-pin universal
trailer connector is attached to a bracket on the hitch
platform.The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed*
Dark Blue: Trailer Brake*
*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your
dealer/retailer or a qualied service center.
If charging a remote (non-vehicle) battery, press the
Tow/Haul mode button, if equipped, located 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, or the vehicle is not equipped with
Tow/Haul, turn on the headlamps as a second way to
boost the vehicle system and charge the battery.
4-72

Engine Fan Noise
If the vehicle has a clutched engine cooling fan, when the
clutch is engaged, the fan spins faster to provide more air
to cool the engine. In most everyday driving conditions,
the fan is spinning slower and the clutch is not fully
engaged. This improves fuel economy and reduces fan
noise. Under heavy vehicle loading, trailer towing, and/or
high outside temperatures, the fan speed increases as
the clutch more fully engages, so you may hear an
increase in fan noise. This is normal and should not be
mistaken as the transmission slipping or making extra
shifts. It is merely the cooling system functioning properly.
The fan will slow down when additional cooling is not
required and the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
If the vehicle has electric cooling fans, you may hear the
fans spinning at low speed during most everyday driving.
The fans may turn off if no cooling is required. Under
heavy vehicle loading, trailer towing, and/or high outside
temperatures, or if you are operating the air conditioning
system, the fans may change to high speed and you
may hear an increase in fan noise. This is normal and
indicates that the cooling system is functioning properly.
The fans will change to low speed when additional
cooling is no longer required.
Power Steering Fluid
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
SeeEngine Compartment
Overview on page 5-14for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering uid
unless you suspect there is a leak in the system or
you hear an unusual noise. A uid loss in this system
could indicate a problem. Have the system inspected
and repaired.
5-38

Load Index:An assigned number ranging from
1 to 279 that corresponds to the load carrying
capacity of a tire.
Maximum Ination Pressure
:The maximum air
pressure to which a cold tire can be inated. The
maximum air pressure is molded onto the sidewall.
Maximum Load Rating
:The load rating for a tire
at the maximum permissible ination pressure
for that tire.
Maximum Loaded Vehicle Weight
:The sum of
curb weight, accessory weight, vehicle capacity
weight, and production options weight.
Normal Occupant Weight
:The number of
occupants a vehicle is designed to seat multiplied
by 150 lbs (68 kg). SeeLoading the Vehicle on
page 4-33.
Occupant Distribution
:Designated seating
positions.
Outward Facing Sidewall
:The side of an
asymmetrical tire that has a particular side that
faces outward when mounted on a vehicle. The
side of the tire that contains a whitewall, bears
white lettering, or bears manufacturer, brand,
and/or model name molding that is higher or deeper
than the same moldings on the other sidewall of the
tire.Passenger (P-Metric) Tire
:A tire used on
passenger cars and some light duty trucks and
multipurpose vehicles.
Recommended Ination Pressure
:Vehicle
manufacturer’s recommended tire ination
pressure as shown on the tire placard. See
Inflation - Tire Pressure on page 5-70andLoading
the Vehicle on page 4-33.
Radial Ply Tire
:A pneumatic tire in which
the ply cords that extend to the beads are laid
at 90 degrees to the centerline of the tread.
Rim
:A metal support for a tire and upon which
the tire beads are seated.
Sidewall
:The portion of a tire between the tread
and the bead.
Speed Rating
:An alphanumeric code assigned to
a tire indicating the maximum speed at which a
tire can operate.
Traction
:The friction between the tire and the
road surface. The amount of grip provided.
Tread
:The portion of a tire that comes into
contact with the road.
5-69