Rivian Gen 2 R1S Diagnostics
Classification: Electric Vehicles Equipment
Hardware operational fault codes, protection alarms, LED blink sequences, and step-by-step diagnostic fixes for the Rivian Gen 2 R1S.
Indexed Fault Codes for Gen 2 R1S
Step-by-step resolution manuals and root cause matrices
HV Contactor Open Isolation Fault
BMS_b018 indicates that the Battery Management System detected an isolation breakdown (chassis leakage < 500 ohms/volt) across the high-voltage bus while main contactors were commanded open or during the pre-charge sequence, triggering an immediate vehicle immobilize safety lockout.
HV Isolation Degradation Warning
BMS_b017 indicates that the Battery Management System has detected a loss of electrical isolation resistance between the 400V/800V high-voltage bus and chassis ground, falling below the critical threshold (typically <500 Ohms/Volt or <100 kΩ total resistance).
HV Isolation Resistance Degraded
The Battery Management System detected chassis-to-HV bus isolation resistance dropping below the safety threshold (typically <500 kΩ or <100 Ω/V). This indicates partial leakage between high-voltage positive or negative rails and vehicle chassis ground.