DTC U0401: Invalid Data Received from ECM/PCM A: Description

WARNING: This page is about a different car, the 2013 Ford Fiesta. However, it is still accessible from the selected car via links, so may be relevant.

The PSCM monitors the HS-CAN bus when the ignition has been on for more than 5 seconds, when the voltage to the PSCM is greater than 10 volts and when there are no DTCs present that are inhibiting PSCM operation.

DTC U0401:00 (Invalid Data Received from ECM/PCM A: No Sub Type Information) - This DTC sets if the PSCM receives invalid or unknown messages from the PCM for ms instead of the valid engine speed, engine state and vehicle speed data messages.