Inflatable Restraint Electronic Frontal Sensor (EFS)

The Electronic Frontal Sensor (EFS) is equipped on some vehicles to supplement SIR system performance. The EFS is an electronic sensor (accelerometer) and is not part of the deployment loops, but instead provides an input to the SDM. The EFS can assists in determining the severity of some frontal collisions. The SDM contains a microprocessor that performs calculations using the measured accelerations. The SDM 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 frontal deployment loops deploying the frontal air bags.