SIR System Overview

SIR System Overview:

The Supplemental Inflatable Restraint (SIR) system supplements the protection offered by the occupant's seat belt system (2). The SIR system has various inflator modules located throughout the vehicle, i.e. inflatable restraint steering wheel module (1), inflatable restraint IP module (1), inflatable restraint side impact module - LF, and the inflatable restraint side impact module - RF. In addition to the inflator modules, the vehicle is equipped with seat belt pretensioners that tighten the seat belt in the event of a collision, thus reducing the distance between the occupant and the steering wheel or IP when an inflator module is deployed. Each inflator module and seat belt pretensioner has a deployment loop that is controlled by the Inflatable Restraint Sensing And Diagnostic Module (SDM). The SDM determines the severity of a collision and commands deployment of each inflator module and seat belt pretensioner. When the SDM detects a collision of sufficient force, it will process the information to further support inflator module and seat belt pretensioner deployment. The SDM performs continuous diagnostic monitoring of the SIR system electrical components. Upon detection of a circuit malfunction, the SDM will set a Diagnostic Trouble Code (DTC) and inform the driver by turning the AIR BAG indicator ON. The steering column and the knee bolsters (3) are designed to absorb energy and compress during frontal collisions in order to limit leg movement and decrease the chance of injury to the driver and passenger.