splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
OPERATION
ACTIVE RESTRAINTS
The primary passenger restraints in this or any
other vehicle are the standard equipment factory-in-
stalled seat belts. Seat belts are referred to as an
active restraint because the vehicle occupants are
required to physically fasten and properly adjust
these restraints in order to benefit from them. See
the owner’s manual in the vehicle glove box for more
information on the features, use and operation of all
of the factory-installed active restraints.
PASSIVE RESTRAINTS
The passive restraints are referred to as a supple-
mental restraint system because they were designed
and are intended to enhance the protection for the
occupants of the vehicle only when used in conjunc-
tion with the seat belts. They are referred to as pas-
sive restraints because the vehicle occupants are not
required to do anything to make them operate; how-
ever, the vehicle occupants must be wearing their
seat belts in order to obtain the maximum safety
benefit from the factory-installed supplemental
restraint system.
The supplemental restraint system electrical cir-
cuits are continuously monitored and controlled by a
microprocessor and software contained within the
Airbag Control Module (ACM). An airbag indicator in
the ElectroMechanical Instrument Cluster (EMIC)
illuminates for about four seconds as a bulb test each
time the ignition switch is turned to the On or Start
positions. Following the bulb test, the airbag indica-
tor is turned on or off by the ACM to indicate the
status of the supplemental restraint system. If the
airbag indicator comes on either solid or flashing at
any time other than during the bulb test, it indicates
that there is a problem in the supplemental restraint
system electrical circuits. Such a problem may cause
airbags not to deploy when required, or to deploy
when not required.
Deployment of the supplemental restraints
depends upon the angle and severity of an impact.
Deployment is not based upon vehicle speed; rather,
deployment is based upon the rate of deceleration as
measured by the forces of gravity (G force) upon the
impact sensor. When an impact is severe enough, the
microprocessor in the ACM signals the inflator of the
appropriate airbag units to deploy their airbag cush-
ions. The front seat belt tensioners are provided with
a deployment signal by the ACM in conjunction with
the driver and passenger airbags. During a frontal
vehicle impact, the knee blockers work in concert
with properly fastened and adjusted seat belts to
restrain both the driver and the front seat passenger
in the proper position for an airbag deployment. The
knee blockers also absorb and distribute the crash
energy from the driver and the front seat passenger
to the structure of the instrument panel. The seat
belt tensioners remove the slack from the front seat
belts to provide further assurance that the driver and
front seat passenger are properly positioned and
restrained for an airbag deployment.
Typically, the vehicle occupants recall more about
the events preceding and following a collision than
they do of an airbag deployment itself. This is
because the airbag deployment and deflation occur so
rapidly. In a typical 48 kilometer-per-hour (30 mile-
per-hour) barrier impact, from the moment of impact
until the airbags are fully inflated takes only a few
milliseconds. Within one to two seconds from the
moment of impact, the airbags are almost entirely
deflated. The times cited for these events are approx-
imations, which apply only to a barrier impact at the
given speed. Actual times will vary somewhat,
depending upon the vehicle speed, impact angle,
severity of the impact, and the type of collision.
When the ACM monitors a problem in any of the
front airbag system circuits or components, including
the seat belt tensioners, it stores a fault code or
Diagnostic Trouble Code (DTC) in its memory circuit
and sends a hard wired output to the EMIC to turn
on the airbag indicator. If the EMIC detects a prob-
lem in the airbag indicator or airbag indicator circuit,
the cluster will flash the seatbelt indicator on and
off. Proper testing of the supplemental restraint sys-
tem components as well as the retrieval or erasure of
a DTC from the ACM requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
See the owner’s manual in the vehicle glove box for
more information on the features, use and operation
of all of the factory-installed passive restraints.
8O - 4 RESTRAINTS VA
RESTRAINTS (Continued)
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