Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2021 Lincoln Corsair, 2021 Lincoln Aviator, 2021 Ford Transit-350 HD, 2021 Ford Transit-350, and 2021 Ford Transit-250. However, it is still accessible from the selected car via links, so may be relevant.
If the vehicle speed signal is the cause of the concern, the PSCM uses a default vehicle speed value and the level of steering assistance does not change as vehicle speed increases or decreases.
DTC U0401:00 indicates an engine speed or vehicle speed message concern. The module reporting this DTC is not the problem module. Do not install a new PSCM as part of the repair for PSCM DTC U0401:00. The PSCM sends a message to the IPC to display STEERING ASSIST FAULT SERVICE REQUIRED in the message center.