Determining if the system is operational
The SRS uses a readiness light in the instrument cluster or a tone to
indicate the condition of the system. Refer to theAirbag readiness
section in theInstrument Clusterchapter. Routine maintenance of the
airbag is not required.
Any difficulty with the system is indicated by one or more of the
following:
•The readiness light (same light as for front airbag system) will either
flash or stay lit.
•The readiness light will not illuminate immediately after ignition is
turned on.
•A series of five beeps will be heard. The tone pattern will repeat
periodically until the problem and light are repaired.
If any of these things happen, even intermittently, have the SRS serviced
at authorized dealer immediately. Unless serviced, the system may not
function properly in the event of a collision or rollover event.
Disposal of airbags and airbag equipped vehicles
(including pretensioners)
See your authorized dealer. Airbags MUST BE disposed of by qualified
personnel.
SAFETY RESTRAINTS FOR CHILDREN
See the following sections for directions on how to properly use safety
restraints for children. Also seeAirbag supplemental restraint system
(SRS)in this chapter for special instructions about using airbags.
Important child restraint precautions
You are required by law to use safety restraints for children in the U.S.
and Canada. If small children (generally children who are four years old
or younger and who weigh 40 lb. [18 kg] or less) ride in your vehicle, you
must put them in safety seats made especially for children. Many states
require that children use approved booster seats until they are eight
years old. Check your local and state or provincial laws for specific
requirements regarding the safety of children in your vehicle. When
possible, always place children under age 12 in the rear seat of your
vehicle. Accident statistics suggest that children are safer when properly
restrained in the rear seating positions than in the front seating position.
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Seating and Safety Restraints
180
Power is supplied to all four wheels through a transfer case or power
transfer unit. 4WD vehicles allow you to select different drive modes as
necessary. Information on transfer case operation and shifting procedures
can be found in theDrivingchapter. Information on transfer case
maintenance can be found in theMaintenance and Specifications
chapter. You should become thoroughly familiar with this information
before you operate your vehicle.
On some 4WD models, the initial shift from two-wheel drive to 4WD
while the vehicle is moving can cause a momentary clunk and ratcheting
sound. These sounds are normal as the front drivetrain comes up to
speed and is not cause for concern.
Do not become overconfident in the ability of 4WD and AWD
vehicles. Although a 4WD or AWD vehicle may accelerate better
than two-wheel drive vehicle in low traction situations, it won’t stop
any faster than two-wheel drive vehicles. Always drive at a safe speed.
How your vehicle differs from other vehicles
SUV and trucks can differ from
some other vehicles in a few
noticeable ways. Your vehicle may
be:
•Higher – to allow higher load
carrying capacity and to allow it
to travel over rough terrain
without getting hung up or
damaging underbody components.
•Shorter – to give it the capability
to approach inclines and drive
over the crest of a hill without
getting hung up or damaging
underbody components. All other
things held equal, a shorter
wheelbase may make your vehicle
quicker to respond to steering inputs than a vehicle with a longer
wheelbase.
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
196
Treadwear
The treadwear grade is a comparative rating based on the wear rate of
the tire when tested under controlled conditions on a specified
government test course. For example, a tire graded 150 would wear one
and one-half (1 1/2) times as well on the government course as a tire
graded 100. The relative performance of tires depends upon the actual
conditions of their use, however, and may depart significantly from the
norm due to variations in driving habits, service practices, and
differences in road characteristics and climate.
Traction AA A B C
The traction grades, from highest to lowest are AA, A, B, and C. The
grades represent the tire’s ability to stop on wet pavement as measured
under controlled conditions on specified government test surfaces of
asphalt and concrete. A tire marked C may have poor traction
performance.
The traction grade assigned to this tire is based on
straight-ahead braking traction tests, and does not include
acceleration, cornering, hydroplaning or peak traction characteristics.
Temperature A B C
The temperature grades are A (the highest), B and C, representing the
tire’s resistance to the generation of heat and its ability to dissipate heat
when tested under controlled conditions on a specified indoor laboratory
test wheel. Sustained high temperature can cause the material of the tire
to degenerate and reduce tire life, and excessive temperature can lead to
sudden tire failure. The grade C corresponds to a level of performance
which all passenger car tires must meet under the Federal Motor Vehicle
Safety Standard No. 139. Grades B and A represent higher levels of
performance on the laboratory test wheel than the minimum required by
law.
The temperature grade for this tire is established for a tire that
is properly inflated and not overloaded. Excessive speed,
underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
TIRES
Tires are designed to give many thousands of miles of service, but they
must be maintained in order to get the maximum benefit from them.
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
198
Every day before you drive, check your tires. If one looks lower than the
others, use a tire gauge to check pressure of all tires and adjust if
required.
At least once a month and before long trips, inspect each tire and check
the tire pressure with a tire gauge (including spare, if equipped). Inflate
all tires to the inflation pressure recommended by Ford Motor Company.
Use a tire gauge to check the tire inflation pressure, including the spare
(if equipped), at least monthly and before long trips. You are strongly
urged to buy a reliable tire pressure gauge, as automatic service station
gauges may be inaccurate. Ford recommends the use of a digital or
dial-type tire pressure gauge rather than a stick-type tire pressure gauge.
Use the recommended cold inflation pressure for optimum tire
performance and wear. Under-inflation or over-inflation may cause
uneven treadwear patterns.
Under-inflation is the most common cause of tire failures and
may result in severe tire cracking, tread separation orblowout,
with unexpected loss of vehicle control and increased risk of injury.
Under-inflation increases sidewall flexing and rolling resistance,
resulting in heat buildup and internal damage to the tire. It also may
result in unnecessary tire stress, irregular wear, loss of vehicle control
and accidents. A tire can lose up to half of its air pressure and not
appear to be flat!
Always inflate your tires to the Ford recommended inflation pressure
even if it is less than the maximum inflation pressure information found
on the tire. The Ford recommended tire inflation pressure is found on
the Safety Compliance Certification Label or Tire Label which is located
on the B-Pillar or the edge of the driver’s door. Failure to follow the tire
pressure recommendations can cause uneven treadwear patterns and
adversely affect the way your vehicle handles.
Maximum Permissible Inflation Pressureis the tire manufacturer’s
maximum permissible pressure and/or the pressure at which the
maximum load can be carried by the tire. This pressure is normally
higher than the manufacturer’s recommended cold inflation pressure
which can be found on the Safety Compliance Certification Label or Tire
Label which is located on the B-Pillar or the edge of the driver’s door.
The cold inflation pressure should never be set lower than the
recommended pressure on the Safety Compliance Certification Label or
Tire Label.
When weather temperature changes occur, tire inflation pressures also
change. A 10°F (6°C) temperature drop can cause a corresponding drop
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
200
TIRE PRESSURE MONITORING SYSTEM (TPMS)
Each tire, including the spare (if
provided), should be checked
monthly when cold and inflated to
the inflation pressure recommended
by the vehicle manufacturer on the
vehicle placard or tire inflation pressure label. (If your vehicle has tires
of a different size than the size indicated on the vehicle placard or tire
inflation pressure label, you should determine the proper tire inflation
pressure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire
pressure monitoring system (TPMS) that illuminates a low tire pressure
telltale when one or more of your tires is significantly under-inflated.
Accordingly, when the low tire pressure telltale illuminates, you should
stop and check your tires as soon as possible, and inflate them to the
proper pressure. Driving on a significantly under-inflated tire causes the
tire to overheat and can lead to tire failure. Under-inflation also reduces
fuel efficiency and tire tread life, and may affect the vehicle’s handling
and stopping ability.
Please note that the TPMS is not a substitute for proper tire
maintenance, and it is the driver’s responsibility to maintain correct tire
pressure, even if under-inflation has not reached the level to trigger
illumination of the TPMS low tire pressure telltale.
Your vehicle has also been equipped with a TPMS malfunction indicator
to indicate when the system is not operating properly. The TPMS
malfunction indicator is combined with the low tire pressure telltale.
When the system detects a malfunction, the telltale will flash for
approximately one minute and then remain continuously illuminated.
This sequence will continue upon subsequent vehicle start-ups as long as
the malfunction exists.
When the malfunction indicator is illuminated, the system may not be
able to detect or signal low tire pressure as intended. TPMS malfunctions
may occur for a variety of reasons, including the installation of
replacement or alternate tires or wheels on the vehicle that prevent the
TPMS from functioning properly. Always check the TPMS malfunction
telltale after replacing one or more tires or wheels on your vehicle to
ensure that the replacement or alternate tires and wheels allow the
TPMS to continue to function properly.
The Tire Pressure Monitoring System complies with part 15 of the FCC
rules and with RSS-210 of Industry Canada. Operation is subject to the
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
212
Low Tire Pressure
Warning LightPossible cause Customer Action Required
Flashing Warning
LightSpare tire in use Your temporary spare tire is in
use. Repair the damaged road
wheel and re-mount it on the
vehicle to restore system
functionality. For a description
of how the system functions
under these conditions, refer to
When your temporary spare
tire is installedin this section.
TPMS
malfunctionIf your tires are properly
inflated and your spare tire is
not in use and the TPMS
warning light still flashes, have
the system inspected by your
authorized dealer.
When inflating your tires
When putting air into your tires (such as at a gas station or in your
garage), the Tire Pressure Monitoring System may not respond
immediately to the air added to your tires.
It may take up to two minutes of driving over 20 mph (32 km/h) for the
light to turn OFF after you have filled your tires to the recommended
inflation pressure.
How temperature affects your tire pressure
The Tire Pressure Monitoring System (TPMS) monitors tire pressure in
each pneumatic tire. While driving in a normal manner, a typical
passenger tire inflation pressure may increase approximately 2 to 4 psi
(14 to 28 kPa) from a cold start situation. If the vehicle is stationary
over night with the outside temperature significantly lower than the
daytime temperature, the tire pressure may decrease approximately 3 psi
(20.7 kPa) for a drop of 30° F (16.6°C) in ambient temperature. This
lower pressure value may be detected by the TPMS as being significantly
lower than the recommended inflation pressure and activate the TPMS
warning for low tire pressure. If the low tire pressure warning light is
ON, visually check each tire to verify that no tire is flat. (If one or more
tires are flat, repair as necessary.) Check air pressure in the road tires. If
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
216
Mode Maximum Gross Trailer
Weight - lb. (kg)Maximum Tongue Weight
- lb. (kg)
Weight
carrying6000 (2721) 600 (272)
Weight
distributing8950 (4059) 895 (405)
These are hitch ratings only; actual vehicle ratings are dependent on
engine, transmission and axle combinations.
Towing trailers beyond the maximum tongue weight exceeds the
limit of the towing system and could result in vehicle structural
damage, loss of vehicle control and personal injury.
Trailer hitch cover
Your vehicle is equipped with a removable trailer hitch trim cover. To
remove the trim cover:
1. Loosen the two
1 4-turn fasteners
in the bottom of the cover by
turning them counterclockwise. Pull
the cover downward to remove it;
the fasteners will remain attached to
the cover.
2. To reinstall the cover, insert the
four plastic tabs on top of the cover
into the corresponding slots, as
shown in the illustration and push
the cover up into the bumper trim.
3. Hold the cover against the
bumper trim and reinstall the two
1 4-turn fasteners by turning them
clockwise.
Preparing to tow
Use the proper equipment for towing a trailer and make sure it is
properly attached to your vehicle. See your authorized dealer or a
reliable trailer dealer if you require assistance.
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
227
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.
This vehicle has a computer assisted cranking system which assists in
starting the engine. If the ignition key is turned to 4 (START) 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 (IF EQUIPPED)
If your vehicle is factory-equipped
with an engine block heater, a
rubber cap/plug assembly will be
visibly attached to the grille on the
front of the vehicle. For factory
equipped, this assembly is loose
shipped in-vehicle for authorized
dealer installation. If not
factory-equipped, the engine block
heater can be purchased through
authorized dealer accessories.
Replacement rubber caps are
available through an authorized
dealer, 3L1Z-6E088-AA.
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
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
235