Circuit/System Description
WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
The K20 Engine Control Module activates the powertrain sensor bus enable circuit (4320) when the ignition is ON or vehicle is in service mode. The powertrain sensor bus enable circuit wakes up the devices on the Powertrain CAN bus for serial data bus communication.