
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

Hitches
Do not use hitches that clamp onto the vehicle bumper. Use a load
carrying hitch. You must distribute the load in your trailer so that
10%–15% of the total weight of the trailer is on the tongue.
The trailer hitch on this vehicle is part of the vehicle rear crash
safety structure. Do not remove the trailer hitch. Failure to
follow this warning could compromise vehicle crash structure and
increase the risk of injury in a rear end collision.
Weight distributing hitch
When hooking up a trailer using a load equalizing hitch, always use the
following procedure:
1. Park the unloaded vehicle on a level surface. With the ignition in the
ON position and all doors closed, allow the vehicle to stand (without
passengers) for several minutes so that it can level.
2. Turn the air suspension (if equipped) control to OFF.
3. Measure the height of a reference point on the front and rear bumpers
at the center of the vehicle.
4. Attach the trailer to the vehicle and adjust the hitch equalizers so that
the front bumper height is within a
1 2” (13 mm) of the reference point.
After proper adjustment, the rear bumper should be no higher than in
Step 3.
5. Turn the air suspension (if equipped) control to ON.
Note:Adjusting a weight distributing hitch so the rear bumper of the
vehicle is higher than it was unloaded will defeat the function of the
weight distributing hitch and may cause unpredictable handling.
Safety chains
Always connect the trailer’s safety chains to the frame or hook retainers
of the vehicle hitch. To connect the trailer’s safety chains, cross the
chains under the trailer tongue and allow slack for turning corners.
If you use a rental trailer, follow the instructions that the rental agency
gives to you.
Do not attach safety chains to the bumper.
Trailer brakes
Electric brakes and manual, automatic or surge-type trailer brakes are
safe if installed properly and adjusted to the manufacturer’s
specifications. The trailer brakes must meet local and Federal
regulations.
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
228

STARTING
Positions of the ignition
1. OFF/LOCK, locks the steering
wheel, automatic transmission
gearshift lever and allows key
removal.
2. ACCESSORY, allows the electrical
accessories such as the radio to
operate while the engine is not
running.
3. ON, all electrical circuits
operational. Warning lights
illuminated. Key position when driving.
4. START, cranks the engine. Release the key once 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, avoid pressing 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 toStarting 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 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
232

4. Make sure the parking brake is
set.
5. Turn the key to 3 (ON) without
turning the key to 4 (START).
Some warning lights will briefly illuminate. SeeWarning lights and
chimesin theInstrument Clusterchapter for more information
regarding the warning lights.
Starting the engine
Note:Whenever you start your vehicle, release the key once the engine
starts.
1. Turn the key to 4 (START)
without pressing the accelerator
pedal and release once the engine
starts. The key will return to 3
(ON).
2. When the engine starts, release
the key.
3. After idling for a few seconds,
apply the brake, shift into gear and
drive.
Note:If the engine does not start within five seconds on the first try,
turn the key to OFF, wait 10 seconds and try again. If the engine still
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
234

•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.
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
Your service brakes are self-adjusting. Refer to thescheduled
maintenance informationfor scheduled maintenance.
Occasional brake noise is normal and often does not indicate a
performance concern with the vehicle’s brake system. In normal
operation, automotive brake systems may emit occasional or intermittent
squeal or groan noises when the brakes are applied. Such noises are
usually heard during the first few brake applications in the morning;
however, they may be heard at any time while braking and can be
aggravated by environmental conditions such as cold, heat, moisture,
road dust, salt or mud. If a “metal-to-metal,” “continuous grinding” or
“continuous squeal” sound is present while braking, the brake linings
may be worn-out and should be inspected by an authorized dealer.
Refer toBrake system warning
lightin theInstrument Cluster
chapter for information on the brake
system warning light.
P!
BRAKE
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
237

If you are driving down a long or steep hill, shift to a lower gear.
Do not apply your brakes continuously, as they may overheat
and become less effective.
Anti-lock brake system (ABS)
On ABS-equipped vehicles, a noise from the hydraulic pump motor and
pulsation in the pedal may be observed during ABS braking events. Pedal
pulsation coupled with noise while braking under panic conditions or on
loose gravel, bumps, wet or snowy roads is normal and indicates proper
functioning of the vehicle’s anti-lock brake system. The ABS performs a
self-check after you start the engine and begin to drive away. A brief
mechanical noise may be heard during this test. This is normal. If a
malfunction is found, the ABS warning light will come on. If the vehicle
has continuous vibration or shudder in the steering wheel while braking,
the vehicle should be inspected by an authorized dealer.
The ABS operates by detecting the onset of wheel lockup during brake
applications and compensates for this tendency. The wheels are
prevented from locking even when the brakes are firmly applied.
Using ABS
•In an emergency or when maximum efficiency from the four-wheel
ABS is required, apply continuous force on the brake. The four wheel
ABS will be activated immediately, thus allowing you to retain steering
control of your vehicle and, providing there is sufficient space, will
enable you to avoid obstacles and bring the vehicle to a controlled
stop.
•The anti-lock system does not always reduce stopping distance.
Always leave enough room between your vehicle and the vehicle in
front of you to stop.
•We recommend that you familiarize yourself with this braking
technique. However, avoid taking any unnecessary risks.
ABS warning lamp
The ABS warning lamp in the
instrument cluster momentarily
illuminates when the ignition is
turned on. If the light does not
illuminate momentarily at start up,
remains on or continues to flash, the ABS needs to be serviced.
ABS
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
238

With the ABS light on, the anti-lock
brake system is disabled and normal
braking is still effective unless the
brake warning light also remains
illuminated with parking brake
released. (If your brake warning lamp illuminates, have your vehicle
serviced immediately.)
Parking brake
Apply the parking brake whenever
the vehicle is parked. To set the
parking brake, press the parking
brake pedal down until the pedal
stops.
The BRAKE warning lamp in the
instrument cluster illuminates and
remains illuminated (when the
ignition is turned ON) until the
parking brake is released.
If the parking brake is fully released, but the brake warning lamp
remains illuminated, the brakes may not be working properly.
See your authorized dealer.
Always set the parking brake fully and make sure that the
gearshift is securely latched in P (Park).
The parking brake is not recommended to stop a moving vehicle.
However, if the normal brakes fail, the parking brake can be used to stop
your vehicle in an emergency. Since the parking brake applies only the
rear brakes, the vehicle’s stopping distance will increase greatly and the
handling of your vehicle will be adversely affected.
P!
BRAKE
P!
BRAKE
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
239

If the parking brake is fully released, but the brake warning lamp
remains illuminated, the brakes may not be working properly.
See your authorized dealer.
Driving with a 6–speed automatic transmission
This vehicle is equipped with an
Adaptive Transmission Shift
Strategy. The Adaptive Transmission
Shift Strategy offers the optimal
transmission operation and shift
quality. When the engine is turned
off, the shift data which includes the
adaptive information will be stored
automatically in the Transmission
Control Module (TCM). If the
battery is disconnected for any
reason, the stored information from
the last time the key was turned to
OFF will be read. This way, no
information will be lost with any
battery removal or battery
disconnect.
P (Park)
This position locks the transmission and prevents the rear wheels from
turning.
To put your vehicle in gear:
•Depress the brake pedal
•Start the engine
•Move the gearshift lever into the desired gear. If your vehicle is
equipped with a floor-shift transmission, press the gearshift lever
release button (on the front of the lever) while shifting into the
desired gear.
To put your vehicle in P (Park):
•Come to a complete stop
•Move the gearshift lever and securely latch it in P (Park)
2008 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Driving
248