"SME FC 21F284 ""HIGH-VOLTAGE BATTERY UNIT, CELL SUPERVISION CIRCUIT: SAFETY CIRCUIT ACTIVATED"". Vehicle is not able to be put in a driving readiness state. Possible power reduction with ""Drivetrain Malfunction"" message while driving. Fault code (FC) ""21F284 -:""High-voltage battery unit, cell supervision circuit: Safety circuit activated"" is entered in the fault memory (FM) of the battery management electronics (SME) A fault in one or more of the following components: cell supervision circuit (CSC) CSC wiring harness cell module temperature sensor 12 volt connector of cell module"
