Ford Vehicle Owner's Manual page 30

The air bag system is designed to stay out of
sight until it is activated. The air bag system is
designed to deploy in frontal and front-angled
collisions more severe than hitting a parked
vehicle of similar size and weight head-on at
about 28 mph (45 km/h). Because the system
senses the crash severity rather than vehicle
speed, some frontal collisions at speeds above
28 mph (45 km/h) will not inflate the air bag.
The system activates when the sensors detect a
forward deceleration equal to or greater than the
deceleration experienced if you would drive
your vehicle into a solid wall at 14 mph. In
some side impacts, the forward deceleration of
your vehicle can be great enough to deploy your
air bag.
The following four steps show how the air bag
system works:
1. Sensors in the vehicle will detect the degree
of severity of a frontal impact. When the
sensor system is activated, electric current
flows to the inflator and the system ignites
the gas generant.
2. The propellant then rapidly burns in the
metal container. The rapid burning produces
nitrogen gas and small amounts of dust. The
nitrogen gas and dust are cooled and filtered
during inflation of the air bag.
3. The inflating supplemental air bag splits
open the trim cover. The supplemental air
bag then rapidly unfolds and inflates in front
of the driver.
NOTE: STEPS 1-3 TAKE PLACE IN A
FRACTION OF A SECOND.
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