DTC U0401-00: Error Data Received From Pcm (HS_Can Or Local Can Between TCM And Pcm) (TCM) (Us): Outline

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

DTC U0401:00 (TCM, EV6A-EL, EV6AX-EL, US) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Error data received from PCM (HS_CAN or local CAN between TCM and PCM)
Detection condition	Under the following condition, the TCM receives an error signal from the PCM (HS_CAN or local CAN between TCM and PCM) for a continuous 0.5 s. Battery voltage is 10 V or more.
Fail-safe	Set to TCC control. Inhibits learning control. Inhibits manual mode. Inhibits neutral idle control. Inhibits 5GR and 6GR. Inhibits shift down when the accelerator pedal is depressed.
Possible cause	PCM DTC is stored.
System wiring diagram	Not applicable
Connector diagram	Not applicable