Conditions for Running the DTC

WARNING: This page is about a different car, the 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

Before the ECM can report DTC P2100 failed, DTC P0638 must run and pass.
The ignition is ON or the engine is operating.
DTC P2100 runs continuously once the above conditions are met for more than 5.0 seconds.