Accessing and Reading Diagnostic Trouble Codes

A scan tool is used to read data lists, current and history diagnostic trouble codes and to clear some diagnostic trouble codes after a repair is completed. Some codes are latched and cannot be cleared. 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 "RUN." The scan tool reads "Serial Data" from the SDM "Serial Data" output terminal "5" to the DLC terminal "9."