Conditions for Setting the DTC
WARNING: This page is about a different car, the 2016 Buick LaCrosse. However, it is still accessible from the selected car via links, so may be relevant.
P0C9E
Low Voltage Circuit Current is less than 2 amps for greater than 2 seconds.
P0C9F
Low Voltage Circuit Current is greater than 123 amps for greater than 2 seconds.