Conditions for Running the DTC
WARNING: This page is about a different car, the 2022 Cadillac CT5. However, it is still accessible from the selected car via links, so may be relevant.
U300D 23
The control module ignition voltage signal is valid, with the ignition in Run or Propulsion Mode.
U300D 24
The control module ignition voltage signal is valid, with the ignition OFF.