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

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

The PCM uses input from several sensors and components to gather vehicle data, then sends this data to the PSCM. If the data is corrupted or invalid, the PCM sends out "invalid", "fault" or "unknown" instead of the actual data. For a list of the messages sent to the PSCM from the PCM, refer to the Network Message List in Description and Operation in the Power Steering article.

• DTC U0401:00 (Invalid Data Received from ECM/PCM A) - This DTC is set if the PSCM receives invalid or unknown messages from the PCM instead of the actual engine speed (non-hybrid), ready light (hybrid) and vehicle speed (all) data messages, and DTC U0001:00 is not present in the PSCM.