Conditions for Setting the DTC
WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
The ratio between Negative Supply Isolation Voltage and Positive Supply Isolation Voltage is greater than 4.53 or less than 0.21 for greater than 2.5 s in a 5 s window.