BMS family
BMS_f037_SW_Pos_Contactor
Unable to start vehicle
What does the BMS_f037_SW_Pos_Contactor alert mean?
The battery management system (BMS) detects that the positive contactor remains open during the first 2 seconds of pack contactors attempting to close.
What you'll see in your Tesla
- Unable to start vehicle
- Service is required
What triggers it
The BMS detects that the positive pack contactor is welded or broken.
When it clears
The positive contactor closes as expected.
Potential impact
Inability to charge, drive, or support the low voltage (LV) system
Affected models
Model S 2012-2020
Model X 2015-2020
Track your Tesla's alerts automatically
Alerts like this reach MyTeslaMate through your car's Tesla telemetry API. MyTeslaMate logs every alert your Tesla reports and turns it into readable history and real-time notifications — hosted TeslaMate with no server to run.