DTC U0121-00: Communication Error With Electronically Controlled Brake Unit/DSC HU/Cm

U0121:00 (DASH_ESU) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Communication error with electronically controlled brake unit/DSC HU/CM
Detection condition	The dash-electrical supply unit cannot receive CAN signal from the electronically controlled brake unit/DSC HU/CM.
Fail-safe	The value of the data which is not received from the electronically controlled brake unit/DSC HU/CM is fixed at the specified value.
Possible cause	Malfunction in CAN communication line between electronically controlled brake unit/DSC HU/CM and dash-electrical supply unit NOTE: Perform the malfunction diagnosis according to the troubleshooting procedure for the multiplex communication system. (See MALFUNCTION DIAGNOSIS FLOW [CONTROLLER AREA NETWORK (CAN)] .)
Repeatability verification procedure	Not applicable
System wiring diagram	Not applicable