Inflatable Restraint Side Impact Sensor (SIS)

The Side Impact Sensor (SIS) is a pressure sensitive device that is used in the detection of side impact collisions. Each SIS is located within the driver and passenger front doors. The SIS monitors pressure changes within each door to detect side collisions that are severe enough to warrant deployment of the inflator module. The SIS is not part of the deployment loop, but instead provides an input to the SDM. The SDM contains a microprocessor that performs calculations using the measured accelerations and compares these calculations to a value stored in memory. When the generated calculations exceed the stored value, the SDM will cause current to flow through the deployment loops, deploying the side impact modules.