P1516 and P2101

WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The ignition is ON.
The ignition voltage is more than 8 volts.
The system is not in the Battery Save mode.
The engine is running.
DTC P0068 is not set.
DTC P1516 and P2101 run continuously when the above conditions are met.