DTC U0401 68: Error Signal Received From Pcm: Notes

WARNING: This page is about a different car, the 2014 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC U0401:68 (FRONT BODY CONTROL MODULE) DETECTION CONDITION AND POSSIBLE CAUSES

Description	Error signal received from PCM
Detection condition	Front body control module (FBCM) receives the error ECT sensor or ambient temperature sensor signals from the PCM for 5 s or more with the ignition switched ON (engine off or on).
Fail-safe function	Not applicable
Possible cause	ECT sensor malfunction Ambient temperature sensor malfunction PCM malfunction Front body control module (FBCM) malfunction
System wiring diagram	Not applicable