2008 FORD EXPEDITION sensor

Driver and passenger dual-stage airbag supplemental restraints
The dual-stage airbags offer the capability to tailor the level of airbag
inflation energy. A lower, less forceful energy level is provided for more
common, moderate-severity impacts. A higher energy level is used for
the most severe impacts. Refer toAirbag supplemental restraints
section in this chapter.
Front crash severity sensor
The front crash severity sensor enhances the ability to detect the
severity of an impact. Positioned up front, it provides valuable
information early in the crash event on the severity of the impact. This
allows your Personal Safety System™ to distinguish between different
levels of crash severity and modify the deployment strategy of the
dual-stage airbags and safety belt pretensioners.
Driver’s seat position sensor
The driver’s seat position sensor allows your Personal Safety System™ to
tailor the deployment level of the driver dual-stage airbag based on seat
position. The system is designed to help protect smaller drivers sitting
close to the driver airbag by providing a lower airbag output level.
Front safety belt usage sensors
The front safety belt usage sensors detect whether or not the driver and
front outboard passenger safety belts are fastened. This information
allows your Personal Safety System™ to tailor the airbag deployment
and safety belt pretensioner activation depending upon safety belt usage.
Refer toSafety restraintssection in this chapter.
Front safety belt pretensioners
The safety belt pretensioners at the front outboard seating positions are
designed to tighten the safety belts firmly against the occupant’s body
during frontal collisions, and in side collisions and rollovers when the
vehicle is equipped with the Safety Canopy™ system. This helps increase
the effectiveness of the safety belts. In frontal collisions, the safety belt
pretensioners can be activated alone or, if the collision is of sufficient
severity, together with the front airbags.
Front safety belt energy management retractors
The front outboard safety belt energy management retractors allow
webbing to be pulled out of the retractor in a gradual and controlled
manner in response to the occupant’s forward momentum. This helps
reduce the risk of force-related injuries to the occupant’s chest by
limiting the load on the occupant. Refer toSafety restraintssection in
this chapter.
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Determining if the Personal Safety System™ is operational
The Personal Safety System™ uses a warning light in the instrument
cluster or a back-up tone to indicate the condition of the system. Refer
to theWarning lights and chimessection in theInstrument Cluster
chapter. Routine maintenance of the Personal Safety System™ is not
required.
The Restraints Control Module (RCM) monitors its own internal circuits
and the circuits for the airbag supplemental restraints, crash sensor(s),
safety belt pretensioners, front safety belt buckle sensors, and the driver
seat position sensor. In addition, the RCM also monitors the restraints
warning light in the instrument cluster. A difficulty with the system is
indicated by one or more of the following:
•The warning light will either flash or stay lit.
•The warning light will not illuminate immediately after the ignition is
turned on.
•A series of five beeps will be heard. The tone pattern will repeat
periodically until the problem and warning light are repaired.
If any of these things happen, even intermittently, have the Personal
Safety System™ serviced at an authorized dealer immediately. Unless
serviced, the system may not function properly in the event of a
collision.
Safety restraints precautions
Always drive and ride with your seatback upright and the lap
belt snug and low across the hips.
To reduce the risk of injury, make sure children sit in the back
seat where they can be properly restrained.
Never let a passenger hold a child on his or her lap while the
vehicle is moving. The passenger cannot protect the child from
injury in a collision.
All occupants of the vehicle, including the driver, should always
properly wear their safety belts, even when an airbag
supplemental restraint system (SRS) is provided.
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2. Grasp the shoulder portion and
pull downward until the entire belt
is pulled out.
3. Allow the belt to retract. As the belt retracts, you will hear a clicking
sound. This indicates the safety belt is now in the automatic locking
mode.
How to disengage the automatic locking mode
Unbuckle the combination lap and shoulder belt and allow it to retract
completely to disengage the automatic locking mode and return to the
vehicle sensitive (emergency) locking mode.
After any vehicle collision, the combination lap and shoulder belt
system at all passenger seating positions must be checked by an
authorized dealer to verify that the “automatic locking retractor”
feature for child seats is still functioning properly, in addition to other
checks for proper safety belt system function.
BELT AND RETRACTOR ASSEMBLY MUST BE REPLACED if
the safety belt assembly “automatic locking retractor” feature or
any other safety belt function is not operating properly. In addition, all
safety belts should be checked for proper function. Failure to replace
the belt and retractor assembly could increase the risk of injury in
collisions.
Safety belt pretensioner
Your vehicle is equipped with safety belt pretensioners at the driver and
right front passenger seating positions.
The safety belt pretensioner removes some slack from the safety belt
system at the start of a crash. The safety belt pretensioner uses the
same crash sensor system as the front airbags and Safety Canopy™
system. When the safety belt pretensioner deploys, the lap and shoulder
belt are tightened.
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Additional equipment may affect the performance of the airbag
sensors increasing the risk of injury.
Children and airbags
Children must always be properly
restrained. Accident statistics
suggest that children are safer when
properly restrained in the rear
seating positions than in the front
seating position. Failure to follow
these instructions may increase the
risk of injury in a collision.
Airbags can kill or injure a
child in a child seat.
NEVERplace a rear-facing child
seat in front of an active airbag. If
you must use a forward-facing
child seat in the front seat, move
the seat all the way back.
How does the airbag supplemental restraint system work?
The airbag SRS is designed to
activate when the vehicle sustains
longitudinal deceleration sufficient
to cause the sensors to close an
electrical circuit that initiates airbag
inflation.
The fact that the airbags did not
inflate in a collision does not mean
that something is wrong with the
system. Rather, it means the forces
were not of the type sufficient to
cause activation. The driver and passenger airbags are designed to inflate
in frontal and near-frontal collisions, not rollover, side-impact, or
rear-impacts unless the collision causes sufficient longitudinal
deceleration.
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The airbags inflate and deflate
rapidly upon activation. After airbag
deployment, it is normal to notice a
smoke-like, powdery residue or
smell the burnt propellant. This may
consist of cornstarch, talcum
powder (to lubricate the bag) or
sodium compounds (e.g., baking
soda) that result from the
combustion process that inflates the
airbag. Small amounts of sodium
hydroxide may be present which
may irritate the skin and eyes, but
none of the residue is toxic.
While the system is designed to help
reduce serious injuries, contact with
a deploying airbag may also cause abrasions, swelling or temporary
hearing loss. Because airbags must inflate rapidly and with considerable
force, there is the risk of death or serious injuries such as fractures,
facial and eye injuries or internal injuries, particularly to occupants who
are not properly restrained or are otherwise out of position at the time
of airbag deployment. Thus, it is extremely important that occupants be
properly restrained as far away from the airbag module as possible while
maintaining vehicle control.
Several air bag system components get hot after inflation. Do not
touch them after inflation.
If the airbag has deployed,the airbag will not function again
and must be replaced immediately.If the airbag is not
replaced, the unrepaired area will increase the risk of injury in a
collision.
The SRS consists of:
•driver and passenger airbag modules (which include the inflators and
airbags),
•one or more impact and safing sensors and diagnostic monitor (RCM),
•a readiness light and tone
•the electrical wiring which connects the components.
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The RCM (restraints control module) monitors its own internal circuits
and the supplemental airbag electrical system wiring (including the
impact sensors, the system wiring, the airbag system readiness light, the
airbag back up power and the airbag ignitors).
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 toAirbag readinesssection
in theInstrument Clusterchapter. Routine maintenance of the airbag is
not required.
A difficulty with the system is indicated by one or more of the following:
•The readiness light 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/or light are repaired.
If any of these things happen, even intermittently, have the SRS serviced
at an authorized dealer immediately. Unless serviced, the system may not
function properly in the event of a collision.
Seat-mounted side airbag system
Do not place objects or mount equipment on or near the airbag
cover on the side of the seatbacks of the front seats or in front
seat areas that may come into contact with a deploying airbag. Failure
to follow these instructions may increase the risk of personal injury in
the event of a collision.
Do not use accessory seat covers. The use of accessory seat
covers may prevent the deployment of the side airbags and
increase the risk of injury in an accident.
Do not lean your head on the door. The side airbag could injure
you as it deploys from the side of the seatback.
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Do not attempt to service, repair, or modify the airbag SRS, its
fuses or the seat cover on a seat containing an airbag. See your
authorized dealer.
All occupants of the vehicle should always wear their safety belts
even when an airbag SRS is provided.
How does the side airbag system work?
The design and development of the side airbag system included
recommended testing procedures that were developed by a group of
automotive safety experts known as the Side Airbag Technical Working
Group. These recommended testing procedures help reduce the risk of
injuries related to the deployment of side airbags.
The side airbag system consists of
the following:
•An inflatable nylon bag (airbag)
with an inflator concealed behind
the outboard bolster of the driver
and front passenger seatbacks.
•A special seat cover designed to
allow airbag deployment.
•The same warning light,
electronic control and diagnostic
unit as used for the front airbags.
•Crash sensors located on the
front doors and C pillars (one
sensor on each pillar on each side
of the vehicle).
Side airbags, in combination with
safety belts, can help reduce the risk of severe injuries in the event of a
significant side impact collision.
The side airbags are fitted on the outboard side of the seatbacks of the
front seats. In certain lateral collisions, the airbag on the side affected by
the collision will be inflated. The airbag was designed to inflate between
the door panel and occupant to further enhance the protection provided
occupants in side impact collisions.
The airbag SRS is designed to activate when the vehicle sustains lateral
deceleration sufficient to cause the sensors to close an electrical circuit
that initiates airbag inflation.
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•Two crash sensors mounted in the front doors (one on each side of
the vehicle).
•Two crash sensors located at the C pillar behind the rear doors (one
on each side of the vehicle).
•Rollover sensor in the restraints control module (RCM).
The Safety Canopy™ system, in combination with safety belts, can help
reduce the risk of severe injuries in the event of a significant side impact
collision or rollover event.
Children 12 years old and under should always be properly restrained in
the second or third row seats. The Safety Canopy™ will not interfere
with children restrained using a properly installed child or booster seat
because it is designed to inflate downward from the headliner above the
doors along the side window opening.
The Safety Canopy™ system is designed to activate when the vehicle
sustains lateral deceleration sufficient to cause the side crash sensor to
close an electrical circuit that initiates Safety Canopy™ inflation or when
a certain likelihood of a rollover event is detected by the rollover sensor.
The Safety Canopy™ is mounted to roof side-rail sheet metal, behind the
headliner, along the entire side of the vehicle. In certain lateral collisions
or rollover events, the Safety Canopy™ system will be activated,
regardless of which seats are occupied. The Safety Canopy™ is designed
to inflate between the side window area and occupants to further
enhance protection provided in side impact collisions and rollover events.
The fact that the Safety Canopy™ did not activate in a collision does not
mean that something is wrong with the system. Rather, it means the
forces were not of the type sufficient to cause activation. The Safety
Canopy™ is designed to inflate in certain side impact collisions or
rollover events, not in rear impact, frontal or near-frontal collisions,
unless the collision causes sufficient lateral deceleration or rollover.
Several Safety Canopy™ system components get hot after
inflation. Do not touch them after inflation.
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