Conditions for Clearing the MIL/DTC

WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.

The ECM turns OFF the MIL after the third consecutive trip in which the TCM does not send an MIL illumination request.
A scan tool can clear the MIL/DTC.
The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.