Circuit Description

Side Impact Sensor (SIS) uses a unidirectional 2-wire circuit. SIS modulates current on the interface to send identification, State Of Health (SOH) and deployment commands to Sensing and Diagnostic Module (SDM). SDM provides power and ground to Side Impact Sensor (SIS). When ignition is turned on and power from SDM is detected by SIS, SIS performs internal diagnostics, then sends an identification message to SDM. SDM receives identification message within 5 seconds of power being turned on and determines if message is valid. SIS continually communicates a status message to SDM. When a fault is detected, SDM resets SIS twice by removing and reapplying power to SIS. If fault is still present, SDM will set DTC.