DTC U0079-00: Unit Communication Error (Can) [Connectivity Master Unit]: 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 U0079:00 (CONNECTIVITY MASTER UNIT) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Unit communication error (CAN)
Detection condition	The connectivity master unit (CMU) detects a CAN BUS communication line (CAN BUS No. 7) malfunction for 2.5 s or more.
Fail-safe	The connectivity master unit (CMU) is put in sleep mode and it does not launch.
Possible cause	Malfunction in CAN bus communication line Connectivity master unit (CMU) malfunction Body control module (BCM) malfunction
System wiring diagram	Not applicable