For 1990-2009 cars

Notice: The order in which diagnostic trouble codes (DTCs) are diagnosed is very important. Failure to diagnose the DTCs in the order specified may result in extended diagnostic time, incorrect diagnosis, and incorrect parts replacement.

A scan tool is used to read current and history diagnostic trouble codes (DTCs) and to clear all diagnostic trouble codes after a reapir is completed. The scan tool must be updated to communicate with the SIR system. To use a scan tool, connect it to the data link connector and turn the ignition switch on. The scan tool reads SDM serial data from the data link connector (DLC).

Current DTCs indicate faults that were present since the last ignition cycle. Current codes can be viewed on the scan tool.

History DTCs indicate faults that may not be currently detected, but have been present in past ignition cycles. History codes can be viewed on the scan tool in the history diagnostic trouble code table. History Codes B0051, B0053, or B1000, cannot be cleared from the SDM.

If a fault occurs intermittently, the first occurrrence will result in a stored history DTC. If the same fault occurs twice within 125 ignition cycles, the air bag telltale will be turned on and will remain on until the vehicle is serviced. The second occurance fault will be stored as a current DTC.