Conditions for Clearing the MIL/DTC
WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
The BCM clears the current status of the DTC when it has learned the first key. The DTC will still be retrieved as current until the ignition switch is cycled. The DTC will become a history DTC at that time.