Circuit Description

When ignition switch is turned to RUN position, Sensing and Diagnostic Module (SDM) performs tests to diagnose critical internal malfunctions. SDM provides input power to Side Impact Sensor (SIS). When input power is first detected, SIS responds by performing internal diagnostics. Next, SIS sends an identification message to SDM.

SDM will consider this to be a valid identification message if response time is less than 5 seconds after SIS powers up. SIS continually communicates a status message to SDM. SDM can reset SIS by removing and applying power to it.