DTC U0401:00 [Radar Unit]: Notes

WARNING: This page is about a different car, the 2016 Mazda CX-5. However, it is still accessible from the selected car via links, so may be relevant.

System malfunction location	Error signal received from PCM
Detection condition	Communication error between PCM and radar unit
Fail-safe	Inhibits the Mazda radar cruise control (MRCC) system control
Possible cause	PCM malfunction (engine speed signal malfunction) Radar unit malfunction
System wiring diagram	Not applicable