| Condition | Threshold | |-----------|------------| | HV system active (contactors closed or in precharge) | Yes | | 12V supply to BMS master stable | 9–16V | | Internal bus wake-up pattern sent by BMS | Completed | | Missing cyclic counter increment from any CSC for > 5 consecutive cycles | Yes | | Or: CRC error rate on internal bus > 30% over 10 seconds | Yes |
Perform HV isolation test to rule out moisture ingress into battery pack (which can short bus lines). mercedes-benz p1d687a
Measure voltage at BMS master connector – must be >11.5V during cranking. | Condition | Threshold | |-----------|------------| | HV
Run XENTRY routine "Check HV battery internal communication" – identifies faulty CSC by position (e.g., "CSC 2 does not respond"). "CSC 2 does not respond").