Conditions For Clearing MIL/DTC

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Sonoma, 2002 GMC Safari, 2002 GMC Jimmy, 2002 Chevrolet S10 Pickup, and 2002 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.

The PCM will turn the MIL OFF during the first consecutive trip in which the diagnostic has been run and passed.
A last test failed (current DTC) clears when the PCM turns OFF the MIL.
The history DTC will clear after the PCM runs and passes 40 consecutive warm up cycles with no failure.
The DTC can be cleared by using a scan tool.