Frontal Restraint Devices
The frontal Supplemental Inflatable Restraint (SIR) system supplements
the protection offered by the driver and front passenger seat belts. The frontal
SIR system deploys an air bag from the center of the steering wheel and
from the right side of the instrument panel.
The seat belt pretensioners remove slack from the driver and passenger
front seat belts during a frontal impact. The frontal SIR system deploys
the seat belt pretensioners with the frontal air bags.
A frontal crash of sufficient force up to 30 degrees off the
longitudinal centerline of the vehicle will deploy the frontal air bags and
the pretensioners. The knee bolsters absorb crash energy. The driver and
passenger knee bolsters are below the instrument panel.
Frontal SIR System Description
The frontal SIR system consists of the following components:
• | Inflatable Restraint Sensing and Diagnostic Module (SDM) |
• | Inflatable Restraint Steering Wheel Module |
• | Inflatable Restraint Steering Wheel Module Coil |
• | Inflatable Restraint IP Module |
• | Inflatable Restraint Driver Seat Module |
• | Inflatable Restraint Passenger Seat Module |
• | Driver Seat Belt Pretensioner |
• | Passenger Seat Belt Pretensioner |
• | Inflatable Restraint Side Impact Sensors |
• | AIR BAG Warning Lamp in the Instrument Panel Cluster |
The inflatable restraint sensing and diagnostic module (SDM), inflatable
restraint steering wheel module coil, inflatable restraint steering wheel
module, inflatable restraint IP module, driver seat belt pretensioner,
front passenger seat belt pretensioner, and the connecting wires make
up the frontal deployment loops. The function of the frontal deployment
loops is to supply current through the frontal inflator modules and the
pretensioners, deploying the frontal inflator modules and the pretensioners
in the event of a mild-to-severe frontal collision. Deployment occurs
when the SDM detects vehicle velocity changes severe enough to warrant
deployment.
The SDM contains a sensing device (accelerometer) that converts vehicle
velocity changes to an electrical signal. The SDM compares this electrical
signal to a value stored in memory. When the generated signal exceeds
the stored value, the SDM performs additional signal processing and compares
the generates signals to values stored in memory. When two of the generated
signals exceed the stored values, the SDM will cause current to flow
through the frontal inflator modules and the pretensioners, deploying
the frontal inflator modules and the pretensioners.
Side Impact Restraint Devices
The side impact air bag system supplements the protection offered by
the driver door, the front passenger door, and the vehicle structure. The
side impact air bag system deploys an air bag from the side of the driver
or front passenger seat. A side crash of sufficient force will deploy
a side air bag.
Side Impact Air Bag System Description
The side impact air bag system consists of the following components:
• | Two Inflatable Restraint Side Impact Sensors (SIS) (One in each
B-pillar) |
• | An Inflatable Restraint Front Side Impact Module (LH) in the driver's
seat |
• | An Inflatable Restraint Front Side Impact Module in the front
passenger's seat |
• | An AIR BAG Warning Lamp in the Instrument Panel Cluster |
• | An Inflatable Restraint Sensing and Diagnostic Module (SDM) |
The inflatable restraint Side Impact Sensor (SIS), the inflatable restraint
front side impact modules, and the connecting wires make up the side impact
deployment loops. The function of the side impact deployment loop is
to supply current through the side impact inflator module, which will
cause deployment of the side impact air bag. Deployment occurs when one
of the SISs detects a side impact severe enough to warrant deployment.
The SIS contains a sensing device (accelerometer) that converts acceleration
into an electrical (analog) signal. This signal is converted by a microprocessor
in the SIS into acceleration and velocity data. This data is used by
a sensing algorithm and compared to various predetermined boundary conditions.
When the acceleration value exceeds the predetermined threshold, and
the velocity boundary is crossed, the SIS will cause current to flow
through the inflatable restraint front side impact module (LH) or the
inflatable restraint front side impact module (RH).