Conditions For Setting DTC

WARNING: This page is about a different car, the 2003 GMC Envoy XL and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The PCM detects that the calibrated amount of engine run time has been met.
The calibrated amount of engine air flow has been met.
The engine coolant temperature for Closed Loop of 90° F (34° C) has not been met.