Action Taken When DTC Sets

WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

If the misfire level is non-catalyst damaging, the PCM will illuminate the MIL during the second key cycle in which the DTC sets.
If the misfire is severe enough to cause possible catalyst damage, the PCM will immediately flash the MIL while the misfire remains at catalyst damaging levels.
The PCM will disable the Torque Converter Clutch (TCC) operation.
The PCM will store the conditions present when the DTC set as Freeze Frame/Failure Records data. Any data previously stored in Freeze Frame will be overwritten when this DTC sets. The only exception to this is if a fuel trim DTC was already recorded in Freeze Frame. In this case, the fuel trim data stays in Freeze Frame and the Misfire Data will be stored in Failure Records.