DTC U0156-00: Communication Error With Connectivity Master Unit (CMU) (BCM) (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 U0156:00 (BCM) (US) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Communication error with connectivity master unit (CMU)
Detection condition	The body control module (BCM) cannot receive CAN signal from the connectivity master unit (CMU).
Fail-safe	Not applicable
Possible cause	Malfunction in CAN communication line between connectivity master unit (CMU) and body control module (BCM)
System wiring diagram	Not applicable