DTC U2121-00: Communication Error With Vehicle Control Module (VCM) [Connectivity Master Unit]: Outline

DTC U2121:00 (CONNECTIVITY MASTER UNIT) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Communication error with vehicle control module (VCM)
Detection condition	The connectivity master unit (CMU) detects a communication interruption or communication error with the vehicle control module (VCM) for approx. 6 s.
Fail-safe	Not applicable
Possible cause	Malfunction in CAN bus communication line Vehicle control module (VCM) malfunction Connectivity master unit (CMU) malfunction
System wiring diagram	Not applicable