Conditions for Running the DTC

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The ignition switch is in the crank or run position.
DTC P0641 is not set.
The ignition voltage is more than 2.25 volts.
DTC P0220 runs continuously when the above conditions are met.