Inflatable Restraint Electronic Frontal Sensor (EFS)
WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
The electronic frontal sensors (EFS) supplement the SIR system performance. Each EFS is an electronic sensor and is not part of the deployment loops, but instead provides an input to the SDM. Each EFS can assist in determining the severity of some frontal collisions. The SDM contains a microprocessor which 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 frontal deployment loops, deploying the frontal air bags.