traction control FORD EXPEDITION 2008 3.G User Guide

conditions. If these messages display when driving in 2H, contact your
authorized dealer as soon as possible. Refer toWarning lights and
chimesin theInstrument Clusterchapter.
•4X4 AUTO– displays when 4A is selected.
•4X4– displays when 4H is selected.
•4X4 LOW– displays when 4L is selected.
Positions of the Control Trac system
The Control Trac system functions
in four modes:
•2H (2WD)delivers power to the
rear wheels only. This is
appropriate for normal on-road
driving on dry pavement.
•4A (4X4 AUTO)provides
electronic control four-wheel
drive with power delivered to all
four wheels, as required, for
increased traction. The RTT location in the message center will
display “4X4 AUTO” when this position is selected. This is appropriate
for all on-road driving conditions, such as dry road surfaces, wet
pavement, snow or gravel.
•4H (4X4)provides electronically locked four-wheel drive power to
front and rear wheels. The RTT location in the message center will
display “4X4” when this position is selected. This position is not
recommended for use on dry pavement. This position is only intended
for severe winter or off-road conditions, such as deep snow, ice or
shallow sand.
•4L (4X4 LOW)provides electronically locked four-wheel drive when
extra power at reduced speeds is required. The RTT location in the
message center will display “4X4 LOW” when this position is selected.
This position is not recommended for use on dry pavement. Use this
position for off-road low-speed operation or when extra power is
required, such as climbing steep grades, going through deep sand or
pulling a boat out of the water.
Note:If your vehicle is equipped with AdvanceTrac
with RSC, the
AdvanceTrac
with RSC system will automatically turn off the stability
enhancement feature when you shift the Control Trac four-wheel drive
system into 4L (4X4 LOW). The brake traction enhancement feature will
still be enabled.
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Do not spin the wheels at over 35 mph (56 km/h). The tires may
fail and injure a passenger or bystander.
Emergency maneuvers
•In an unavoidable emergency situation where a sudden sharp turn
must be made, remember to avoid “over-driving” your vehicle, i.e.,
turn the steering wheel only as rapidly and as far as required to avoid
the emergency. Excessive steering will result in less vehicle control,
not more. Additionally, smooth variations of the accelerator and/or
brake pedal pressure should be utilized if changes in vehicle speed are
called for. Avoid abrupt steering, acceleration or braking which could
result in an increased risk of loss of vehicle control, vehicle rollover
and/or personal injury. Use all available road surface to return the
vehicle to a safe direction of travel.
•In the event of an emergency stop, avoid skidding the tires and do not
attempt any sharp steering wheel movements.
Vehicles with a higher center of gravity such as utility and
four-wheel drive vehicles handle differently than vehicles with a
lower center of gravity. Utility and four-wheel drive vehicles arenot
designed for cornering at speeds as high as passenger cars any more
than low-slung sports cars are designed to perform satisfactorily under
off-road conditions. Avoid sharp turns, excessive speed and abrupt
maneuvers in these vehicles. Failure to drive cautiously could result in
an increased risk of loss of vehicle control, vehicle rollover, personal
injury and death.
•If the vehicle goes from one type of surface to another (i.e., from
concrete to gravel) there will be a change in the way the vehicle
responds to a maneuver (steering, acceleration or braking). Again,
avoid these abrupt inputs.
Control Trac four–wheel drive system (if equipped)
When a four–wheel drive mode is selected, the Control Trac system uses
all four wheels to power the vehicle. This increases traction, enabling
you to drive over terrain and road conditions that a conventional
two-wheel drive vehicle cannot.
Power is supplied to all four wheels through a transfer case. On
four–wheel drive vehicles, the transfer case allows you to select
four–wheel drive when necessary. Information on transfer case operation
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and shifting procedures can be found in this chapter. Information on
transfer case maintenance can be found in theMaintenance and
Specificationschapter. You should become thoroughly familiar with this
information before you operate your vehicle.
Normal characteristics
On some four–wheel drive models, the initial shift from two-wheel drive to
four–wheel drive while the vehicle is moving can cause some momentary
clunk and ratcheting sounds. This is the front drivetrain coming up to
speed and engaging the front wheels, and is not cause for concern.
Sand
When driving over sand, try to keep all four wheels on the most solid
area of the trail. Avoid reducing the tire pressures but shift to a lower
gear and drive steadily through the terrain. Apply the accelerator slowly
and avoid spinning the wheels.
Note:If air is released from your tires, the Tire Pressure Monitoring
System (TPMS) indicator light may illuminate.
Avoid excessive speed because vehicle momentum can work against you
and cause the vehicle to become stuck to the point that assistance may
be required from another vehicle. Remember, you may be able to back
out the way you came if you proceed with caution.
If your vehicle is equipped with AdvanceTrac
with RSC, press the
AdvanceTrac
with RSC button (refer toAdvanceTrac
with Roll
Stability Control (RSC) Stability Enhancement Systemin this
chapter) while driving in deep sand if you experience excessive engine
power reduction.
Mud and water
If you must drive through high
water, drive slowly. Traction or
brake capability may be limited.
When driving through water,
determine the depth; avoid water
higher than the bottom of the hubs
(if possible) and proceed slowly. If the ignition system gets wet, the
vehicle may stall.
Once through water, always try the brakes. Wet brakes do not stop the
vehicle as effectively as dry brakes. Drying can be improved by moving
your vehicle slowly while applying light pressure on the brake pedal.
Be cautious of sudden changes in vehicle speed or direction when you
are driving in mud. Even four–wheel drive vehicles can lose traction in
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slick mud. As when you are driving over sand, apply the accelerator
slowly and avoid spinning your wheels. If the vehicle does slide, steer in
the direction of the slide until you regain control of the vehicle.
If the transmission, transfer case, front axle or rear axle are submerged
in water, their fluids should be checked and changed, if necessary.
Driving through deep water may damage the transmission.
If the front or rear axle is submerged in water, the axle lubricant should
be replaced.
After driving through mud, clean off residue stuck to rotating driveshafts
and tires. Excess mud stuck on tires and rotating driveshafts causes an
imbalance that could damage drive components.
“Tread Lightly” is an educational
program designed to increase public
awareness of land-use regulations
and responsibilities in our nations
wilderness areas. Ford Motor
Company joins the U.S. Forest Service and the Bureau of Land
Management in encouraging you to help preserve our national forest and
other public and private lands by “treading lightly.”
Driving on hilly or sloping terrain
Although natural obstacles may make it necessary to travel diagonally up
or down a hill or steep incline, you should always try to drive straight up
or straight down.Avoid driving crosswise or turning on steep
slopes or hills. A danger lies in losing traction, slipping sideways and
possibly rolling over. Whenever driving on a hill, determine beforehand
the route you will use. Do not drive over the crest of a hill without
seeing what conditions are on the other side. Do not drive in reverse
over a hill without the aid of an observer.
When climbing a steep slope or hill,
start in a lower gear rather than
downshifting to a lower gear from a
higher gear once the ascent has
started. This reduces strain on the
engine and the possibility of stalling.
If you do stall out, do not try to
turn around because you might roll
over. It is better to back down to a
safe location.
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Apply just enough power to the wheels to climb the hill. Too much
power will cause the tires to slip, spin or lose traction, resulting in loss of
vehicle control.
Descend a hill in the same gear you
would use to climb up the hill to
avoid excessive brake application
and brake overheating. Do not
descend in neutral; instead,
disengage overdrive or manually
shift to a lower gear. When
descending a steep hill, avoid
sudden hard braking as you could
lose control. When you brake hard,
the front wheels can’t turn and if
they aren’t turning, you won’t be
able to steer. The front wheels have to be turning in order to steer the
vehicle. Rapid pumping of the brake pedal will help you slow the vehicle
and still maintain steering control.
If your vehicle has anti-lock brakes, apply the brakes steadily. Do not
“pump” the brakes.
Driving on snow and ice
Four–wheel drive vehicles have advantages over two–wheel drive
vehicles in snow and ice but can skid like any other vehicle.
Should you start to slide while driving on snowy or icy roads, turn the
steering wheel in the direction of the slide until you regain control.
Avoid sudden applications of power and quick changes of direction on
snow and ice. Apply the accelerator slowly and steadily when starting
from a full stop.
Avoid sudden braking as well. Although a four–wheel drive vehicle may
accelerate better than a two-wheel drive vehicle in snow and ice, it won’t
stop any faster, because as in other vehicles, braking occurs at all four
wheels. Do not become overconfident as to road conditions.
Make sure you allow sufficient distance between you and other vehicles
for stopping. Drive slower than usual and consider using one of the lower
gears. In emergency stopping situations, apply the brake forcefully and
steadily. Do not “pump” the brakes. Refer to theBrakessection of this
chapter for additional information on the operation of the anti-lock brake
system.
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Maintenance and Modifications
The suspension and steering systems on your vehicle have been designed
and tested to provide predictable performance whether loaded or empty
and durable load carrying capability. For this reason, Ford Motor
Company strongly recommends that you do not make modifications such
as adding or removing parts (such as lift kits or stabilizer bars) or by
using replacement parts not equivalent to the original factory equipment.
Any modifications to a vehicle that raise the center of gravity can make
it more likely the vehicle will roll over as a result of a loss of control.
Ford Motor Company recommends that caution be used with any vehicle
equipped with a high load or device (such as ladder racks or pickup box
cover).
Failure to maintain your vehicle properly may void the warranty, increase
your repair cost, reduce vehicle performance and operational capabilities
and adversely affect driver and passenger safety. Frequent inspection of
vehicle chassis components is recommended if the vehicle is subjected to
heavy off-road usage.
DRIVING THROUGH WATER
If driving through deep or standing
water is unavoidable, proceed very
slowly especially when the depth is
not known. Never drive through
water that is higher than the bottom
of the wheel rims (for cars) or the
bottom of the hubs (for trucks).
When driving through water, traction or brake capability may be limited.
Also, water may enter your engine’s air intake and severely damage your
engine or your vehicle may stall.Driving through deep water where
the transmission vent tube is submerged may allow water into the
transmission and cause internal transmission damage.
Once through the water, always dry the brakes by moving your
vehicle slowly while applying light pressure on the brake pedal.
Wet brakes do not stop the vehicle as quickly as dry brakes.
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