Scan Tool Testing and Procedures: Description and Operation

A scan tool is used to read data lists, current and history diagnostic trouble codes and to clear all diagnostic trouble codes after a repair is completed. The scan tool must be updated to communicate with the SIR system through a replaceable cartridge before it can be used for SIR diagnostics. To use the scan tool, connect it to the data link connector and turn the ignition switch to ON. The scan tool reads Serial Data from the inflatable restraint Sensing and Diagnostic Module (SDM) Serial Data output terminal 1 to the Data Link Connector (DLC) terminal 9.

The Tech 2 scan tool displays information that the SDM sends to the Tech 2 over the Universal Asynchronous Receiver Transmitter (UART) serial data line.