Sensing & Diagnostic Module (SDM)

SDM monitors vehicle velocity changes to detect frontal collisions which are severe enough to warrant air bag module deployment. When a frontal collision of sufficient force is detected, SDM causes current to flow through air bag module deployment loops, causing air bag modules to deploy. SDM also maintains a 23 Volt Loop Reserve (23 VLR) energy supply to provide deployment energy for up to one minute after loss of voltage.

Additionally, SDM provides diagnostic monitoring of SIR system electrical components. When a malfunction is detected, SDM sets a Diagnostic Trouble Code (DTC) which can be retrieved using a scan tool. SDM warns driver of system malfunctions by controlling AIR BAG warning light.