Conditions for Setting the DTC
WARNING: This page is about a different car, the 2013 GMC Yukon XL, 2013 GMC Yukon, 2013 Chevrolet Tahoe, 2013 Chevrolet Suburban, and 2013 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The voltage above 18.5 volts, or below 10.5 volts, and a mode shift is requested.