
6. If the trailer wheels lock-up (indicated by squealing tires), reduce the
GAIN setting; if the trailer wheels turn freely, increase the GAIN setting.
Repeat Steps 5 and 6 until the GAIN setting is at a point just below
trailer wheel lock-up. If towing a heavier trailer, trailer wheel lockup may
not be attainable even with the maximum GAIN setting of 10.
Explanation of instrument cluster messages:
The TBC interacts with the instrument cluster message center. These
messages, accompanied by a single chime, will be displayed when the
TBC determines a malfunction in the trailer connection, TBC system, or
in the trailer. These messages are listed below:
TRAILER DISCONNECTED (if equipped with message center) or
CHECK TRAILER (if equipped with mini message center):This
message is displayed when a trailer connection was determined and then
a disconnection, either intentionally or unintentionally, has been sensed
during a given ignition cycle. It is also displayed if a trailer fault occurs
causing the trailer to appear disconnected. This message is also
displayed during manual activation without a trailer connected.
TBC FAULT:This message is displayed in response to faults sensed by
the TBC. In the event this message is seen, please take your vehicle to
an authorized dealer for diagnosis and repair. The TBC may still function,
but performance may be degraded.
WIRING FAULT ON TRAILER:The TBC is capable of determining
certain faults in the vehicle wiring and trailer wiring/brake system. These
faults do not mean there is anything wrong with the TBC. This message
is displayed when one of the following faults has occurred:
•Short circuit on the electric brake output wire:If the TRAILER
FAULT message is displayed with no trailer connected, the problem is
with the vehicle wiring from the TBC to the 7–pin connector in the
bumper. If the message is only displayed with a trailer connected, the
problem is related to the trailer wiring; consult your trailer dealer for
assistance. This can be a short to ground (i.e., chaffed wire) or a short
to voltage (i.e., pulled pin on trailer emergency break-away battery) or
trailer brakes drawing too much current.
Note:Your TBC can be diagnosed by your authorized dealer to
determine exactly which trailer fault has occurred; however, if the fault
is with the trailer this diagnosis isnotcovered under your Ford
warranty.
Points to Remember:
•Remember to adjust gain setting before using the TBC for the first
time.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
249

•Readjust GAIN setting on the TBC (according to procedure above)
whenever road, weather and trailer or vehicle loading conditions
change from those that existed when the gain was initially set.
•The sliding lever on the TBC should be used only for manual
activation of trailer brakes to assist with proper adjustment of the
GAIN. Misuse, such as application during trailer sway, could cause
instability of trailer and/or tow vehicle.
•Avoid towing in adverse weather conditions. The TBC does not
provide anti-lock control of the trailer wheels. Trailer wheels can
lock-up on slippery surfaces, resulting in reduced stability of trailer
and tow vehicle.
•The TBC interacts with the brake system of the vehicle, including
ABS, in order to reduce the likelihood of trailer wheel lockup.
Therefore, if these systems are not functioning properly the TBC may
not function at full performance.
•When the vehicle is turned off, the TBC Output is disabled and the
display is shut down. Reactivation of the ignition from 3 (OFF) to 4
(ON) will awaken the TBC module.
•The TBC is only a factory or dealer installed item. Ford is not
responsible for warranty or performance of the TBC due to misuse or
customer installation.
•Do not attempt removal of the TBC without consulting the
Workshop Manual.Damage to the unit may result.
Trailer lamps
Trailer lamps are required on most towed vehicles. Make sure all running
lights, brake lights, turn signals and hazard lights are working. See your
authorized dealer or trailer rental agency for proper instructions and
equipment for hooking up trailer lamps.
Using a step bumper (if equipped)
The rear bumper is equipped with an integral hitch and only requires a
ball with a one inch (2.5 cm) shank diameter. The bumper has a 5,000
lb. (2,270 kg) trailer weight and 500 lb. (227 kg) tongue weight capacity.
If it is necessary to relocate the trailer hitch ball position, a
frame-mounted trailer hitch must be installed.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
250

Transmission Drivetrain
configurationRequirements for
neutral towing
Manual 4x2 Place transmission
into (N) Neutral
1
Manual 4x4 with manual-shift
transfer caseTransmission in (N)
Neutral; Transfer case
in (N) (Neutral);
Hublocks set to FREE
1Automatic
Manual 4x4 with
electronic-shift
transfer caseDo not tow your
vehicle with any
wheels on the ground,
as vehicle or
transmission damage
may occur. It is
recommended to tow
your vehicle with all
four (4) wheels off the
ground such as when
using a car-hauling
trailer. Otherwise, no
recreational towing is
permitted. Automatic
1Always make sure that both hub locks are set to the same position.
In case of a roadside emergency with a disabled vehicle, seeWrecker
Towingin theRoadside Emergencieschapter.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
254

STARTING
Positions of the ignition
1. OFF/LOCK, shuts off the engine
and all accessories/locks the steering
wheel, gearshift lever and allows key
removal.
2. ACC, allows the electrical
accessories such as the radio to
operate while the engine is not
running. This position also unlocks
the steering wheel.
3. ON, all electrical circuits
operational. Warning lights illuminated. Key position when driving.
4. START, cranks the engine. Release the key as soon as the engine
starts.
Preparing to start your vehicle
Engine starting is controlled by the powertrain control system. This
system meets all Canadian Interference-Causing Equipment standard
requirements regulating the impulse electrical field strength of radio
noise.
When starting a fuel-injected engine, don’t press the accelerator before
or during starting. Only use the accelerator when you have difficulty
starting the engine. For more information on starting the vehicle, refer to
Starting the enginein this chapter.
Extended idling at high engine speeds can produce very high
temperatures in the engine and exhaust system, creating the risk
of fire or other damage.
Do not park, idle, or drive your vehicle in dry grass or other dry
ground cover. The emission system heats up the engine
compartment and exhaust system, which can start a fire.
Do not start your vehicle in a closed garage or in other enclosed
areas. Exhaust fumes can be toxic. Always open the garage door
before you start the engine. SeeGuarding against exhaust fumesin
this chapter for more instructions.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
255

Note:If the engine does not start on the first try, turn the key to OFF,
wait 10 seconds and try again. If the engine still fails to start, press the
accelerator to the floor and try again; this will allow the engine to crank
with the fuel shut off in case the engine is flooded with fuel.
If your vehicle has an automatic transmission,it will have a
computer assisted cranking system. This feature assists in starting the
engine. If the ignition key is turned to the 4 (START) position, and then
released when the engine begins cranking, the engine may continue
cranking for up to 10 seconds or until the vehicle starts
Guarding against exhaust fumes
Carbon monoxide is present in exhaust fumes. Take precautions to avoid
its dangerous effects.
If you smell exhaust fumes inside your vehicle, have your dealer
inspect your vehicle immediately. Do not drive if you smell
exhaust fumes.
Important ventilating information
If the engine is idling while the vehicle is stopped for a long period of
time, open the windows at least one inch (2.5 cm) or adjust the heating
or air conditioning to bring in fresh air.
ENGINE BLOCK HEATER
An engine block heater warms the engine coolant which aids in starting
and allows the heater/defroster system to respond quickly. If your vehicle
is equipped with this system, your equipment includes a heater element
which is installed in your engine block and a wire harness which allows
the user to connect the system to a grounded 120 volt a/c electrical
source. The block heater system is most effective when outdoor
temperatures reach below 0°F (-18°C).
Failure to follow engine block heater instructions could result in
property damage or physical harm.
To reduce the risk of electrical shock, do not use your heater
with ungrounded electrical systems or two-pronged (cheater)
adapters.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
258

Prior to using the engine block heater, follow these recommendations for
proper and safe operation:
•For your safety, use an outdoor extension cord that is product
certified by Underwriter’s laboratory (UL ) or Canadian Standards
Association (CSA). Use only an extension cord that can be used
outdoors, in cold temperatures, and is clearly markedSuitable for Use
with Outdoor Appliances.Never use an indoor extension cord
outdoors; it could result in an electric shock or fire hazard.
•Use a 16 gauge outdoor extension cord, minimum.
•Use as short an extension cord as possible.
•Do not use multiple extension cords. Instead, use one extension cord
which is long enough to reach from the engine block heater cord to
the outlet without stretching.
•Make certain that the extension cord is in excellent condition (not
patched or spliced). Store your extension cord indoors at
temperatures above 32°F (0°C). Outdoor conditions can deteriorate
extension cords over a period of time.
•To reduce the risk of electrical shock, do not use your heater with
ungrounded electrical systems or two pronged (cheater) adapters.
Also ensure that the block heater, especially the cord, is in good
condition before use.
•Make sure that when in operation, the extension cord plug /engine
block heater cord plug connection is free and clear of water in order
to prevent possible shock or fire.
•Be sure that areas where the vehicle is parked are clean and clear of
all combustibles such as petroleum products, dust, rags, paper and
similar items.
•Be sure that the engine block heater, heater cord and extension cord
are solidly connected. A poor connection can cause the cord to
become very hot and may result in an electrical shock or fire. Be sure
to check for heat anywhere in the electrical hookup once the system
has been operating for approximately a half hour.
•Finally, have the engine block heater system checked during your fall
tune-up to be sure it’s in good working order.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
259

How to Use the Engine Block Heater
Ensure the receptacle terminals are clean and dry prior to use. To clean
them, use a dry cloth.
Depending on the type of factory installed equipment, your engine block
heater system may consume anywhere between 400 watts or 1000 watts
of energy per hour. Your factory installed block heater system does not
have a thermostat; however, maximum temperature is attained after
approximately 3 hours of operation. Block heater operation longer than 3
hours will not improve system performance and will unnecessarily use
additional electricity.
Make sure system is unplugged and properly stowed before driving the
vehicle. While not in use, make sure the protective cover seals the
prongs of the engine block heater cord plug.
BRAKES
Occasional brake noise is normal. If a metal-to-metal, continuous grinding
or continuous squeal sound is present, the brake linings may be worn-out
and should be inspected by your authorized dealer. If the vehicle has
continuous vibration or shudder in the steering wheel while braking, the
vehicle should be inspected by your authorized dealer.
Refer toBrake system warning
lightin theInstrument Cluster
chapter for information on the brake
system warning light.
Four-wheel anti-lock brake system (ABS)
Your vehicle is equipped with an Anti-lock Braking System (ABS). This
system helps you maintain steering control during emergency stops by
keeping the brakes from locking. Noise from the ABS pump motor and
brake pedal pulsation may be observed during ABS braking and the
brake pedal may suddenly travel a little farther as soon as ABS braking is
done and normal brake operation resumes. These are normal
characteristics of the ABS and should be no reason for concern.
P!
BRAKE
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
260

Vehicles with a higher center of gravity such as utility vehicles
and trucks handle differently than vehicles with a lower center
of gravity. Utility vehicles and trucks arenotdesigned 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 or 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.
Loaded vehicles, with a higher center of gravity, may handle
differently than unloaded vehicles. Do not overload your vehicle
and use extra precautions, such as driving at slower speeds, avoiding
abrupt steering changes and allowing for increased stopping distance,
when driving a heavily loaded vehicle. Over loading or loading the
vehicle improperly can deteriorate handling capability and contribute
to loss of vehicle control and vehicle rollover.
AUTOMATIC TRANSMISSION OPERATION (IF EQUIPPED)
Brake-shift interlock
This vehicle is equipped with a brake-shift interlock feature that prevents
the gearshift lever from being moved from P (Park) when the ignition is
in the 3 (ON) position and the brake pedal is not depressed.
If you cannot move the gearshift lever out of the P (Park) position with
the ignition in the 3 (ON) position and the brake pedal depressed:
1. Apply the parking brake. Turn the
ignition key to 1 (OFF/LOCK), then
remove the key. Locate the access
cover plate for the brake-shift
interlock override. It is located on
top of the steering column shroud.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
265