DTC Will Clear
WARNING: This page is about a different car, the 1997 Cadillac Seville, 1997 Cadillac Eldorado, and 1997 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
For current DTC: ignition switch turned to OFF position, or SDM receives message response over Serial Data Line Class 2. For history DTC: a scan tool CLEAR CODES command is issued, or 250 malfunction free ignition cycles have occurred.