Conditions for Running the DTC

WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The ignition is in Run or Crank.
The ignition voltage is greater than 6.0 V.
The reduced engine power is Inactive.
DTCs P0641 and P0651 run continuously when the above conditions are met.