DTC U2123-00: Communication Error With Front Side Radar Sensor (LH) [Vehicle Control Module]: Outline

WARNING: This page is about a different car, the 2021 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

DTC U2123:00 [VEHICLE CONTROL MODULE] DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Communication error with front side radar sensor (LH)
Detection condition	The vehicle control module (VCM) cannot receive CAN signal from the front side radar sensor (LH) for 10 s.
Fail-safe	(See DTC TABLE [VEHICLE CONTROL MODULE (US)] .)
Possible cause	Power is not supplied from vehicle control module (VCM) to front side radar sensor (LH) Malfunction in CAN communication line between vehicle control module (VCM) and front side radar sensor (LH) Front side radar sensor (LH) malfunction Vehicle control module (VCM) malfunction (built into body control module (BCM))
System wiring diagram	Not applicable