Clearing Trouble Codes

A scan tool is used to read 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 read for SIR diagnostics. To use the scan tool, connect to the data link connector and turn the ignition switch "ON. The scan tool reads serial data from the SDM "Serial Data" output terminal "A3" and "B3" to the data link connector terminal "M" over the UART data line.