Black plate (4,1)GMC Yukon/Yukon XL Owner Manual - 2011
9-4 Driving and Operating
Braking
SeeBrake System Warning Light on
page 5‑23.
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
100 km/h (60 mph) travels 20 m
(66 ft). 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 accessories can
affect vehicle performance. See
Accessories and Modifications on
page 10‑3.
Black plate (6,1)GMC Yukon/Yukon XL Owner Manual - 2011
9-6 Driving and Operating
The fact that such emergency
situations are always possible is a
good reason to practice defensive
driving at all times and wear safety
belts properly.
Off-Road Recovery
The vehicle's right wheels can drop
off the edge of a road onto the
shoulder while driving.
If the level of the shoulder is
only slightly below the pavement,
recovery should be fairly easy. Ease
off the accelerator and then, if thereis nothing in the way, steer so that
the vehicle straddles the edge of
the pavement. Turn the steering
wheel 8 to 13 cm (3 to 5 in), about
one-eighth turn, until the right front
tire contacts the pavement edge.
Then turn the steering wheel to go
straight down the roadway.
Loss of Control
Let us review what driving experts
say about what happens when the
three control systems
—brakes,
steering, and acceleration —do not
have enough friction where the tires
meet the road to do what the driver
has asked.
In any emergency, do not give up.
Keep trying to steer and constantly
seek an escape route or area of
less danger.
Skidding
In a skid, a driver can lose control of
the vehicle. Defensive drivers avoid
most skids by taking reasonable
care suited to existing conditions,
and by not overdriving those
conditions. But skids are always
possible.
The three types of skids correspond
to the vehicle's three control
systems. In the braking skid, the
wheels are not rolling. In the
steering or cornering skid, too much
speed or steering in a curve causes
tires to slip and lose cornering force.
And in the acceleration skid, too
much throttle causes the driving
wheels to spin.
If the vehicle starts to slide, ease
your foot off the accelerator pedal
and quickly steer the way you
want the vehicle to go. If you start
steering quickly enough, the vehicle
may straighten out. Always be ready
for a second skid if it occurs.
Black plate (11,1)GMC Yukon/Yukon XL Owner Manual - 2011
Driving and Operating 9-11
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.
Black plate (14,1)GMC Yukon/Yukon XL Owner Manual - 2011
9-14 Driving and Operating
Exit on the uphill side and stay clear
of the path the vehicle would take if
it rolled downhill. If the vehicle has
a transfer case with a N (Neutral)
position, do not shift the transfer
case to Neutral when you leave the
vehicle. Leave it in some gear.
{WARNING
If the vehicle has the two‐speed
automatic transfer case, shifting
the transfer case to Neutral can
cause your vehicle to roll even if
the transmission is in P (Park).
This is because the Neutral
position on the transfer case
overrides the transmission. You
or someone else could be injured.
If you are going to leave your
vehicle, set the parking brake
and shift the transmission to
P (Park). But, if the vehicle has
a two‐speed automatic transfer
case, do not shift the transfer
case to Neutral.
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.
Black plate (18,1)GMC Yukon/Yukon XL Owner Manual - 2011
9-18 Driving and Operating
Driving 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.(Continued)
WARNING (Continued)
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
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.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road
is wet enough and you are going
fast enough. When the vehicle is
hydroplaning, it has little or no
contact with the road. There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping
equipment in good shape.
.Keep the windshield washer fluid
reservoir filled.
.Have good tires with proper
tread depth. See
Tires on
page 10‑48.
.Turn off cruise control.
Black plate (21,1)GMC Yukon/Yukon XL Owner Manual - 2011
Driving and Operating 9-21
WARNING (Continued)
If the vehicle is stuck in the snow:
.Clear away snow from around
the base of your vehicle,
especially any that is blocking
the exhaust pipe.
.Check again from time to
time to be sure snow does
not collect there.
.Open a window about 5 cm
(2 in) on the side of the
vehicle that is away from the
wind to bring in fresh air.
.Fully open the air outlets on
or under the instrument
panel.(Continued)
WARNING (Continued)
.Adjust the climate control
system to a setting that
circulates the air inside the
vehicle and set the fan speed
to the highest setting. See
Climate Control System in the
Index.
For more information about
carbon monoxide, see Engine
Exhaust on page 9‑36.
Snow can trap exhaust gases
under your vehicle. This can
cause deadly CO (Carbon
Monoxide) gas to get inside. CO
could overcome you and kill you.
You cannot see it or smell it, so
you might not know it is in your
vehicle. Clear away snow from
around the base of your vehicle,
especially any that is blocking the
exhaust. Run the engine for short periods
only as needed to keep warm, but
be careful.
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.
Black plate (22,1)GMC Yukon/Yukon XL Owner Manual - 2011
9-22 Driving and Operating
If the Vehicle is Stuck
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
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).For information about using tire
chains on the vehicle, see
Tire
Chains on page 10‑70.
Rocking the Vehicle to Get
it Out
Turn the steering wheel left and
right to clear the area around the
front wheels. For four-wheel-drive
vehicles, shift into Four‐Wheel High
or, if the vehicle has a two‐speed
automatic transfer case, Four‐Wheel
Low. For vehicles with StabiliTrak
®,
turn the traction control part of the
system off. 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, see
Towing the
Vehicle on page 10‑93.
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.
Black plate (30,1)GMC Yukon/Yukon XL Owner Manual - 2011
9-30 Driving and Operating
3. Come to a complete stop, shiftto P (Park), and turn the ignition
to LOCK/OFF. On vehicles with
an automatic transmission, the
shift lever must be in P (Park) to
turn the ignition switch to the
LOCK/OFF position.
4. Set the parking brake. See Parking Brake on page 9‑51.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
doesn't work, then the vehicle needs
service.
Notice: Using a tool to force the
key to turn in the ignition could
cause damage to the switch or
break the key. Use the correct
key, make sure it is all the way in,
and turn it only with your hand.
If the key cannot be turned by
hand, see your dealer. B (ACC/ACCESSORY):
This
position lets things like the radio
and the windshield wipers operate
while the engine is off. Use this
position if the vehicle must be
pushed or towed.
C (ON/RUN): This position can
be used to operate the electrical
accessories and to display some
instrument panel cluster warning
and indicator lights. The switch
stays in this position when the
engine is running. The transmission
is also unlocked in this position on
automatic transmission vehicles.
If you leave the key in the ACC/
ACCESSORY or ON/RUN position
with the engine off, the battery could
be drained. You may not be able to
start the vehicle if the battery is
allowed to drain for an extended
period of time. D (START):
This is the position that
starts the engine. When the engine
starts, release the key. The ignition
switch returns to ON/RUN for
driving.
A warning tone will sound when
the driver door is opened and the
ignition is in ACC/ACCESSORY or
LOCK/OFF, and the key is in the
ignition.
Starting the Engine
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Move the shift lever to P (Park) or
N (Neutral). The engine will not start
in any other position. To restart the
engine when the vehicle is already
moving, use N (Neutral) only.