2009 GMC YUKON service

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

Off-roading can be great fun but has some denite
hazards. The greatest of these is the terrain itself. When
off-road driving, traffic lanes are not marked, curves
are not banked, and there are no road signs. Surfaces
can be slippery, rough, uphill, or downhill.
Avoid sharp turns and abrupt maneuvers. Failure to
operate the vehicle correctly off-road could result in loss
of vehicle control or vehicle rollover.
Off-roading involves some new skills. That is why it is
very important that you read these driving tips and
suggestions to help make off-road driving safer
and more enjoyable.
Before You Go Off-Roading
Have all necessary maintenance and service
work done.
Make sure there is enough fuel, that uid levels are
where they should be, and that the spare tire, if the
vehicle has one, is fully inated.
Be sure to read all the information about
four-wheel-drive vehicles in this manual.
Make sure all underbody shields, if the vehicle has
them, are properly attached.
Know the local laws that apply to off-roading where
you will be driving or check with law enforcement
people in the area.
Be sure to get the necessary permission if you will
be on private land.
If you think you will need some more ground clearance
at the front of your vehicle, you can remove the front
fascia lower air dam. The air dam is held in place by
two bolts and 10 snaps accessible from underneath the
front fascia.
To remove the air dam:
1. Remove the two outboard air dam bolts.
2. With a at-blade tool, disengage the snaps.
3. After the bolts are removed and the snaps are
disengaged, push forward on the air dam until it
is free.
Notice:Operating your vehicle for extended
periods without the front fascia lower air dam
installed can cause improper air ow to the engine.
Always be sure to replace the front fascia air
dam when you are nished off-road driving.
After off-roading, be sure to reinstall the air dam:
1. Line up the snaps and push the air dam rearward
to engage the snaps.
2. Install the two outboard bolts.
4-13

Driving in Water
{CAUTION:
Driving through rushing water can be dangerous.
Deep water can sweep your vehicle downstream
and you and your passengers could drown. If it is
only shallow water, it can still wash away the
ground from under your tires, and you could lose
traction and roll the vehicle over. Do not drive
through rushing water.
Heavy rain can mean ash ooding, and ood waters
demand extreme caution.
Find out how deep the water is before driving through it.
Do not try it if it is deep enough to cover the wheel
hubs, axles, or exhaust pipe — you probably will not get
through. Deep water can damage the axle and other
vehicle parts.If the water is not too deep, drive slowly through it. At
faster speeds, water splashes on the ignition system and
the vehicle can stall. Stalling can also occur if you get the
tailpipe under water. If the tailpipe is under water, you will
never be able to start the engine. When going through
water, remember that when the brakes get wet, it might
take longer to stop. SeeDriving in Rain and on Wet
Roads on page 4-26.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis, or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires, and exhaust system
for damage and check the fuel lines and cooling system
for any leakage.
The vehicle requires more frequent service due to
off-road use. Refer to the Maintenance Schedule for
additional information.
4-24

Before Leaving on a Long Trip
To prepare your vehicle for a long trip, consider having
it serviced by your dealer/retailer before departing.
Things to check on your own include:
Windshield Washer Fluid:Reservoir full? Windows
clean — inside and outside?
Wiper Blades:In good shape?
Fuel, Engine Oil, Other Fluids:All levels checked?
Lamps:Do they all work and are lenses clean?
Tires:Are treads good? Are tires inated to
recommended pressure?
Weather and Maps:Safe to travel? Have
up-to-date maps?
Highway Hypnosis
Always be alert and pay attention to your surroundings
while driving. If you become tired or sleepy, nd a
safe place to park your vehicle and rest.
Other driving tips include:
Keep the vehicle well ventilated.
Keep interior temperature cool.
Keep your eyes moving — scan the road ahead
and to the sides.
Check the rearview mirror and vehicle instruments
often.
4-27

Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on at or rolling terrain. Tips for driving
in these conditions include:
Keep the vehicle serviced and in good shape.
Check all uid levels and brakes, tires, cooling
system, and transmission.
Going down steep or long hills, shift to a
lower gear.
{CAUTION:
If you do not shift down, the brakes could get so
hot that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Shift down to let the engine
assist the brakes on a steep downhill slope.
{CAUTION:
Coasting downhill in N (Neutral) or with the ignition
off is dangerous. The brakes will have to do all the
work of slowing down and they could get so hot
that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Always have the engine running
and the vehicle in gear when going downhill.
Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
Top of hills: Be alert — something could be in your
lane (stalled car, accident).
Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
SeeOff-Road Driving on page 4-12for information
about driving off-road.
4-28

Towing
Towing Your Vehicle
To avoid damage, the disabled vehicle should be towed
with all four wheels off the ground. Consult your
dealer/retailer or a professional towing service if the
disabled vehicle must be towed. SeeRoadside
Assistance Program on page 7-7.
To tow the vehicle behind another vehicle for
recreational purposes (such as behind a motorhome),
see “Recreational Vehicle Towing” following.
Recreational Vehicle Towing
Recreational vehicle towing means towing the vehicle
behind another vehicle – such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as dinghy towing and dolly towing.
Dinghy towing is towing the vehicle with all four wheels
on the ground. Dolly towing is towing the vehicle
with two wheels on the ground and two wheels up on a
device known as a dolly.Here are some important things to consider before
recreational vehicle towing:
What is the towing capacity of the towing vehicle?
Be sure to read the tow vehicle manufacturer’s
recommendations.
What is the distance that will be travelled? Some
vehicles have restrictions on how far and how
long they can tow.
Is the proper towing equipment going to be used?
See your dealer/retailer or trailering professional
for additional advice and equipment
recommendations.
Is the vehicle ready to be towed? Just as preparing
the vehicle for a long trip, make sure the vehicle is
prepared to be towed. SeeBefore Leaving on a
Long Trip on page 4-27.
4-44

The Trailer Brake Display Page can be displayed by
performing any of the following actions:
Scrolling through the DIC menu pages using the
odometer trip stem or the DIC Vehicle Information
button (if equipped).
Pressing a Trailer Gain button – If the Trailer Brake
Display Page is not currently displayed, pressing a
Trailer Gain button will rst recall the current
Trailer Gain setting. After the Trailer Brake Display
Page is displayed, each press and release of
the gain buttons will then cause the Trailer Gain
setting to change.
Activating the Manual Trailer Brake Apply lever
Connecting a trailer equipped with electric trailer
brakes
All DIC warning and service messages must rst be
acknowledged by the driver by pressing the odometer trip
stem or the DIC Vehicle Information button (if equipped)
before the Trailer Brake Display Page can be displayed
and Trailer Gain can be adjusted.
TRAILER GAIN – This setting is displayed anytime the
Trailer Brake Display Page is active. This setting can be
adjusted from 0.0 to 10.0 with either a trailer connected or
disconnected. To adjust the Trailer Gain, press one of the
Trailer Gain adjustment buttons located on the TrailerBrake Control Panel. Press and hold a gain button to
cause the Trailer Gain to continuously adjust. To turn the
output to the trailer off, adjust the Trailer Gain setting to
0.0 (zero).
0.0 (zero) gain is the factory default setting. To properly
adjust trailer gain, see the Trailer Gain Adjustment
Procedure later in this section.
TRAILER OUTPUT – This is displayed any time a trailer
with electric brakes is connected. Output to the electric
brakes is based on the amount of vehicle braking
present and relative to the Trailer Gain setting. Output is
displayed from 0 to 10 bars for each gain setting.
The Trailer Output will indicate “------“ontheTrailer
Brake Display Page whenever the following occur:No trailer is connected.
A trailer without electric brakes is connected (no
DIC message is displayed).
A trailer with electric brakes has become
disconnected (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
There is a fault present in the wiring to the electric
trailer brakes (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
There is a fault in the ITBC system (a SERVICE
TRAILER BRAKE SYSTEM message will also
be displayed in the DIC).
4-64

Manual Trailer Brake Apply
The Manual Trailer Brake Apply Lever is located on the
Trailer Brake Control Panel and is used to apply the
trailer’s electric brakes independent of the vehicle’s
brakes. This lever is used in the Trailer Gain Adjustment
Procedure to properly adjust the power output to the
trailer brakes. Sliding the lever to the left will apply only
the trailer brakes. The power output to the trailer is
indicated in the Trailer Brake Display Page in the DIC.
If the vehicle’s service brakes are applied while using the
Manual Trailer Brake Apply Lever, the trailer output
power will be the greater of the two.
The trailer and the vehicle’s brake lamps will come on
when either vehicle braking or manual trailer brakes are
applied.
Trailer Gain Adjustment Procedure
Trailer Gain should be set for a specic trailering
condition and must be adjusted any time vehicle loading,
trailer loading or road surface conditions change.
Setting the Trailer Gain properly is needed for the best
trailer stopping performance. A trailer that is over-gained
may result in locked trailer brakes. A trailer that is
under-gained may result in not enough trailer braking.
Both of these conditions may result in poorer stopping
and stability of the vehicle and trailer.Use the following procedure to correctly adjust Trailer
Gain for each towing condition:
1. Make sure the trailer brakes are in proper working
condition.
2. Connect a properly loaded trailer to the vehicle and
make all necessary mechanical and electrical
connections. SeeLoading the Vehicle on page 4-33
for more information.
3. After the electrical connection is made to a trailer
equipped with electric brakes:
A TRAILER CONNECTED message will be
briey displayed on the DIC display.
The Trailer Brake Display Page will appear on
the DIC showing TRAILER GAIN and TRAILER
OUTPUT.
In the Trailer Output display on the DIC, “------“
will disappear if there is no error present.
Connecting a trailer without electric brakes
will not clear the six dashed lines.
4. Adjust the Trailer Gain by using the gain adjustment
(+ / -) buttons on the Trailer Brake Control Panel.
4-65