BMS-W123
BMS_w123_SW_Internal_Isolation
Also written as BMS_W123 / BMS W123 / BMS_w123_SW_Internal_Isolation / bms_w123_sw_internal_isolation
Why does the exact Tesla alert ID matter?
Record the exact alert ID, including underscores, suffixes, and companion alerts. Tesla alerts that look similar can point to different modules, timestamps, and service procedures.
What does BMS-W123 mean?
Tesla warning code in the Battery Management System (BMS) module. The Battery Management System (BMS) has detected that the isolation resistance internal to the high voltage (HV) battery has exceeded the threshold while the contactors are open. If this alert is present, the isolation has dropped below 190 kOhm with the contactors open. The alert will clear when the isolation exceeds 380 kOhm threshold while the contactors are open.
Original Description
The Battery Management System (BMS) has detected that the isolation resistance internal to the high voltage (HV) battery has exceeded the threshold while the contactors are open. If this alert is present, the isolation has dropped below 190 kOhm with the contactors open. The alert will clear when the isolation exceeds 380 kOhm threshold while the contactors are open.
Affected Tesla Models
What You May Notice
- Battery management warning: The Battery Management System (BMS) has detected that the isolation resistance internal to the high voltage (HV) battery
- Charging speed may be limited or sessions interrupted early
- Reduced estimated range may appear on the touchscreen
How to Diagnose and Resolve
- 1 Perform a soft reboot: hold both scroll wheels until the screen restarts
- 2 Try a full charge cycle to recalibrate the BMS
- 3 If "The Battery Management System (BMS) has detected t" persists after reboot, schedule a Tesla Service appointment
- 4 Avoid DC fast charging until the issue is resolved
Severity Notes
BMS-W123 is a Warning in the Battery Management System system. Schedule service soon. Monitor your vehicle for additional warnings.