With Scan Tool

A scan tool is used in order to read current diagnostic trouble codes and history diagnostic trouble codes. Verity the scan tool contains updated software before attempting to communicate with the SIR system. Connect the tool to the OBD 2 data link connector, and turn the ignition switch to the ON position. The scan tool reads Serial Data from the inflatable restraint Sensing and Diagnostic Module (SDM) Serial Data output terminal 1 to the OBD 2 DLC terminal 9.

The scan too displays information that the SDM sends to the scan tool over the UART serial data line.