BMS family
BMS_a129_SW_VSH_Failure
Vehicle may not restart
What does the BMS_a129_SW_VSH_Failure alert mean?
The battery management system (BMS) has detected a high voltage sense harness (VSH) impedance.
What you'll see in your Tesla
- Vehicle may not restart
- Service is required
What triggers it
The BMS detects a VSH impedance value above the threshold.
When it clears
All bricks report VSH impedance values within the threshold.
Potential impact
Inability to charge, drive, or support the low voltage (LV) system
Affected models
Model 3 2017-2023
Model 3 2024+
Model S 2021+
Model X 2021+
Model Y
Model Y 2025+
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