DTC U0001: High Speed CAN Communications Bus: Description

WARNING: This page is about a different car, the 2020 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

The PSCM monitors the HS-CAN messages when the ignition has been on for more than 5 seconds, when the voltage to the PSCM is greater than 9 volts and when there are no DTCs present inhibiting PSCM operation.

DTC U0001:88 (High Speed CAN Communication Bus: Bus Off) - This DTC sets if the PSCM detects a failure of the HS-CAN.