Conditions For Clearing MIL/DTC

WARNING: This page is about a different car, the 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.

The Last Test Failed status will clear when the DTC runs and passes.
The History status will clear after 40 consecutive warm-up cycles with no failures of any DTC.
All DTC Information can be cleared using a scan tool.
Interruption of AF ECM or PCM power or ground may clear DTC Information. Clearing DTC Information with this method is inconsistent and should not be performed.