Conditions for Setting the DTC
WARNING: This page is about a different car, the 2020 Buick Regal and 2019 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
P0090 - P0092, P00C8, P00C9, P00CA
Control Circuit = Commanded state does not match the actual state - For greater than 1 s
P163A
Fuel Pressure Regulator - Electrical Current = Not within a calibrated range - For greater than 10 s