Suzuki XL7 2007 Service Manual page 2016

8B-4 Air Bag System:
Dual Stage Inflator Modules
Dual stage inflator modules contain a housing, inflatable
air bag, two initiating devices, canister of gas generating
material and, in some cases, stored compressed gas.
The two initiators are part of the frontal deployment loop.
The function of the frontal deployment loops are to
supply current through the steering wheel and
instrument panel (I/P) inflator modules to deploy the air
bags. The inflator modules have two stages of
deployment, which varies the amount of restraint to the
occupant according to the collision severity. For
moderate frontal collisions the inflator modules deploy at
less than full deployment (low deployment) which
consists of stage 1 of the inflator module. For more
severe frontal collisions a full deployment is initiated
which consists of stage 1 and stage 2 of the inflator
module. The current passing through the initiators
ignites the material in the canister producing a rapid
generation of gas and is some cases, the release of
compressed gas. The gas produced from this reaction
rapidly inflates the air bag. Once the air bag is inflated it
quickly deflates through the air bag vent holes and/or the
bag fabric.
Each dual stage inflator modules is equipped with a
shorting bar located in the connectors of the module.
The shorting bar shorts the inflator module deployment
loop circuitry to prevent unwanted deployment of the air
bag when it is disconnected.
Inflatable Restraint Seat Belt Retractor
Pretensioners
The seat belt retractor pretensioners consist of a
housing, a seat belt retractor, the seat belt webbing, an
initiator, and a canister of gas generating materials. The
initiator is part of the seat belt pretensioner deployment
loop. When the vehicle is involved in a collision of
sufficient force, the sensing and diagnostic module
(SDM) causes current to flow through the seat belt
deployment loops to the initiator. Current passing
through the initiator ignites the material in the canister
producing a rapid generation of gas. The gas produced
from this reaction deploys the seat belt pretensioners
and retracts the seat belt webbing, which removes all of
the slack in the seat belts. Depending on the severity of
the collision, the seat belt pretensioners may deploy
without the frontal inflator modules deploying, or they will
deploy immediately before the frontal inflator modules
deploy. Each seat belt pretensioner is equipped with a
shorting bar that is located in the connector of the seat
belt pretensioner. The shorting bar shorts the seat belt
pretensioner circuitry to prevent unwanted deployment
of the seat belt pretensioner when the connector is
disconnected.
Inflatable Restraint Steering Wheel Module Coil
The steering wheel module coil is attached to the
steering column and is located under the steering wheel.
The steering wheel module coil consists of two or more
current-carrying coils. The coils allow the rotation of the
steering wheel while maintaining continuous electrical
contact between the driver deployment loop and the
steering wheel module. Two or four, if equipped with dual
stage air bags, coil wires are used for the steering wheel
module deployment loop. Additional coil wires are used
for accessories attached to the steering wheel
depending on the vehicle model. The steering wheel
module coil connector is located near the base of the
steering column. The connector contains a shorting bar
that shorts the steering wheel module coil deployment
loop circuitry to prevent unwanted deployment of the air
bag when servicing the inflator module.
Steering Column and Wheel
The steering wheel and columns are designed to absorb
energy when driver contact is made with the steering
wheel or inflated air bag. In a frontal collision the driver
may come in contact with the steering wheel directly or
load the steering wheel and column through the inflated
air bag. When the driver applies load to the air bag or the
steering wheel the column will compress downward
absorbing some of the impact, helping to reduce bodily
injuries to the driver. The steering wheel and column
must be inspected for damages after a collision.
Knee Bolster
The knee bolsters are designed to help restrain the
lower torso of front seat occupants by absorbing the
energy through the front seat occupants upper legs. In a
frontal collision the front seat occupant legs may come in
contact with the knee bolsters. The knee bolsters are
designed to crush or deform, absorbing some of the
impact, which helps to reduce bodily injuries. The driver
and passenger knee bolsters are located in the lower
part of the instrument panel and must be inspected for
damages after a collision.
Side SIR System Description
The side supplemental inflatable restraint (SIR) system
consists of the following components:
• AIR BAG indicator located in the instrument panel
cluster (IPC)
• Inflatable restraint sensing and diagnostic module
(SDM)
• Inflatable restraint side impact sensors (SIS)
• Inflatable restraint roof rail modules
• Inflatable restraint wiring harnesses