DTC U0121-00: Communication Error With DSC HU/Cm [Dash-Electrical Supply Unit (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 U0121:00 [DASH-ELECTRICAL SUPPLY UNIT (US)] DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Communication error with DSC HU/CM
Detection condition	The dash-electrical supply unit cannot receive CAN signal from the DSC HU/CM.
Fail-safe	The value of the data which is not received from the DSC HU/CM is fixed at the specified value.
Possible cause	Malfunction in CAN communication line between DSC HU/CM and dash-electrical supply unit
System wiring diagram	Not applicable
Connector diagram	Not applicable