light GMC YUKON DENALI 2010 Owners Manual

Surface Obstacles :Unseen or hidden obstacles can
be hazardous. A rock, log, hole, rut, or bump can startle
you if you are not prepared for them. Often these
obstacles are hidden by grass, bushes, snow, or even
the rise and fall of the terrain itself.
Some things to consider:
.Is the path ahead clear?
.Will the surface texture change abruptly up ahead?
.Does the travel take you uphill or downhill?
.Will you have to stop suddenly or change direction
quickly?
When driving over obstacles or rough terrain, keep a
firm grip on the steering wheel. Ruts, troughs, or other
surface features can jerk the wheel out of your hands.
When driving over bumps, rocks, or other obstacles, the
wheels can leave the ground. If this happens, even with
one or two wheels, you cannot control the vehicle as
well or at all.
Because you will be on an unpaved surface, it is
especially important to avoid sudden acceleration,
sudden turns, or sudden braking.
Off-roading requires a different kind of alertness from
driving on paved roads and highways. There are no
road signs, posted speed limits, or signal lights. Use
good judgment about what is safe and what is not.
Driving on Hills
Off-road driving often takes you up, down, or across a
hill. Driving safely on hills requires good judgment and
an understanding of what the vehicle can and cannot
do. There are some hills that simply cannot be driven,
no matter how well built the vehicle.
{WARNING:
Many hills are simply too steep for any vehicle.
If you drive up them, you will stall. If you drive
down them, you cannot control your speed. If you
drive across them, you will roll over. You could be
seriously injured or killed. If you have any doubt
about the steepness, do not drive the hill.
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Driving Downhill
When off-roading takes you downhill, consider:
.How steep is the downhill? Will I be able to
maintain vehicle control?
.What is the surface like? Smooth? Rough?
Slippery? Hard-packed dirt? Gravel?
.Are there hidden surface obstacles? Ruts? Logs?
Boulders?
.What is at the bottom of the hill? Is there a hidden
creek bank or even a river bottom with large
rocks?
If you decide you can go down a hill safely, try to keep
the vehicle headed straight down. Use a low gear so
engine drag can help the brakes so they do not have to
do all the work. Descend slowly, keeping the vehicle
under control at all times.
{WARNING:
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could
cause loss of control and a serious accident.
Apply the brakes lightly when descending a hill
and use a low gear to keep vehicle speed under
control. Things not to do when driving down a hill:
.When driving downhill, avoid turns that take you
across the incline of the hill. A hill that is not too
steep to drive down might be too steep to drive
across. The vehicle could roll over.
.Never go downhill with the transmission in
N (Neutral), called free-wheeling. The brakes will
have to do all the work and could overheat
and fade.
Vehicles are much more likely to stall when going uphill,
but if it happens when going downhill: 1. Stop the vehicle by applying the regular brakes and apply the parking brake.
2. Shift to P (Park) and, while still braking, restart the engine.
3. Shift back to a low gear, release the parking brake, and drive straight down.
4. If the engine will not start, get out and get help.
5-20

Driving at Night
Night driving is more dangerous than day driving
because some drivers are likely to be impaired—by
alcohol or drugs, with night vision problems, or by
fatigue.
Night driving tips include:
.Drive defensively.
.Do not drink and drive.
.Reduce headlamp glare by adjusting the inside
rearview mirror.
.Slow down and keep more space between you and
other vehicles because headlamps can only light
up so much road ahead.
.Watch for animals.
.When tired, pull off the road.
.Do not wear sunglasses.
.Avoid staring directly into approaching headlamps.
.Keep the windshield and all glass on your vehicle
clean —inside and out.
.Keep your eyes moving, especially during turns or
curves.
No one can see as well at night as in the daytime. But,
as we get older, these differences increase.
A 50-year-old driver might need at least twice as much
light to see the same thing at night as a 20-year-old.
Driving in Rain and on Wet Roads
Rain and wet roads can reduce vehicle traction and
affect your ability to stop and accelerate. Always drive
slower in these types of driving conditions and avoid
driving through large puddles and deep‐standing or
flowing water.
{WARNING:
Wet brakes can cause crashes. They might not
work as well in a quick stop and could cause
pulling to one side. You could lose control of the
vehicle.
After driving through a large puddle of water or a
car/vehicle wash, lightly apply the brake pedal
until the brakes work normally.
Flowing or rushing water creates strong forces.
Driving through flowing water could cause your
vehicle to be carried away. If this happens, you
and other vehicle occupants could drown. Do not
ignore police warnings and be very cautious about
trying to drive through flowing water.
5-24

To save fuel, run the engine for only short periods as
needed to warm the vehicle and then shut the engine
off and close the window most of the way to save heat.
Repeat this until help arrives but only when you feel
really uncomfortable from the cold. Moving about to
keep warm also helps.
If it takes some time for help to arrive, now and then
when you run the engine, push the accelerator pedal
slightly so the engine runs faster than the idle speed.
This keeps the battery charged to restart the vehicle
and to signal for help with the headlamps. Do this as
little as possible to save fuel.If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free the
vehicle when stuck in sand, mud, ice, or snow. See
Rocking Your Vehicle to Get It Out on page 5‑30.
If the vehicle has a traction system, it can often help to
free a stuck vehicle. Refer to the vehicle's traction
system in the Index. If stuck too severely for the traction
system to free the vehicle, turn the traction system off
and use the rocking method.
{WARNING:
If the vehicle's tires spin at high speed, they can
explode, and you or others could be injured. The
vehicle can overheat, causing an engine
compartment fire or other damage. Spin the
wheels as little as possible and avoid going above
55 km/h (35 mph) as shown on the speedometer.
For information about using tire chains on the vehicle,
see Tire Chains on page 6‑78.
5-29

Rocking Your Vehicle to Get It Out
Turn the steering wheel left and right to clear the area
around the front wheels. Turn off any traction or stability
system. Shift back and forth between R (Reverse) and a
forward gear, spinning the wheels as little as possible.
To prevent transmission wear, wait until the wheels stop
spinning before shifting gears. Release the accelerator
pedal while shifting, and press lightly on the accelerator
pedal when the transmission is in gear. Slowly spinning
the wheels in the forward and reverse directions causes
a rocking motion that could free the vehicle. If that does
not get the vehicle out after a few tries, it might need to
be towed out. Recovery hooks can be used, if the
vehicle has them. If the vehicle does need to be towed
out, seeTowing Your Vehicle on page 5‑37.
Recovery Hooks
{WARNING:
These hooks, when used, are under a lot of force.
Always pull the vehicle straight out. Never pull on
the hooks at a sideways angle. The hooks could
break off and you or others could be injured from
the chain or cable snapping back.
Notice:Never use recovery hooks to tow the
vehicle. Your vehicle could be damaged and it
would not be covered by warranty.
Your vehicle has recovery hooks at the front of the
vehicle. You can use them if you are stuck off-road and
need to be pulled to some place where you can
continue driving.
5-30

5. Secure the vehicle to the dolly following themanufacturer's instructions.
6. Use an adequate clamping device designed for towing to ensure that the front wheels are locked
into the straight position.
7. Turn the ignition to LOCK/OFF.
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 inflate, 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”under
Towing a Trailer
on page 5‑42for more information.
5-41

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. See
Tow/Haul Mode
on
page 3‑34for 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 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.
5-48

Trailer Wiring Harness
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 qualified service center.
If charging a remote (non-vehicle) battery, press the
tow/haul mode button 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, turn on the headlamps as a second way
to boost the vehicle system and charge the battery.
5-59

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 instrument panel
contains blunt cut wires near the data link connector for
the trailer brake controller. The harness contains the
following wires:
.Dark Blue: Brake Signal to Trailer Connector
.Red/Black: Battery
.Light Blue/White: Brake Switch
.White: Ground
It should be installed by your dealer/retailer or a
qualified service center.
If the vehicle is equipped with an ITBC, the blunt cuts
exist, but are not connected further in the harness. If an
aftermarket trailer brake controller is installed, the ITBC
must be disconnected. Do not power both ITBC and
aftermarket controllers to control the trailer brakes at the
same time.
Trailer Recommendations
Subtract the hitch loads from the Cargo Weight Rating
(CWR). CWR is the maximum weight of the load the
vehicle can carry. It does not include the weight of the
people inside, but you can figure about 150 lbs. (68 kg)
for each passenger. The total cargo load must not be
more than the vehicles CWR.
Weigh the vehicle with the trailer attached, so the
GVWR or GAWR are not exceeded. If using a
weight-distributing hitch, weigh the vehicle without the
spring bars in place.
The best performance is obtained by correctly
spreading out the weight of the load and choosing the
correct hitch and trailer brakes.
For more information see Towing a Trailer
on
page 5‑42.
5-60

Gasoline Octane
Use premium unleaded gasoline with a posted octane
rating of 91 or higher. You can also use regular
unleaded gasoline rated at 87 octane or higher, but the
vehicle's acceleration could be slightly reduced, and a
slight audible knocking noise, commonly referred to as
spark knock, might be heard. If the octane is less than
87, you might notice a heavy knocking noise when you
drive. If this occurs, use a gasoline rated at 87 octane
or higher as soon as possible. Otherwise, you could
damage the engine. If heavy knocking is heard when
using gasoline rated at 87 octane or higher, the engine
needs service.
Gasoline Specifications
At a minimum, gasoline should meet ASTM
specification D 4814 in the United States or
CAN/CGSB‐3.5 or 3.511 in Canada. Some gasolines
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl (MMT).
We recommend against the use of gasolines containing
MMT. SeeAdditives
on page 6‑6for additional
information.
California Fuel
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 might fail a smog‐check test.
See Malfunction Indicator Lamp
on page 4‑35. If this
occurs, return to your authorized dealer/retailer for
diagnosis. If it is determined that the condition is caused
by the type of fuel used, repairs might not be covered
by the vehicle warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, nothing should have to be added to the fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. To help keep fuel
injectors and intake valves clean, or if the vehicle
6-6