bms_a066
Moderate
Tesla · Sedans
High voltage isolation fault detected
Quick Answer
Error code BMS_a066 on your Tesla Sedans means: High voltage isolation fault detected. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Park vehicle in safe location and isolate from power source
2
Check for visible water damage or moisture inside battery pack access points
3
Inspect all visible high-voltage cables for cracks, cuts, or degradation
4
Perform BMS isolation resistance test via diagnostic tool
5
Contact Tesla service for high-voltage battery pack evaluation and potential replacement
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
HV cable harness
High-voltage connector kit
Battery pack sealing compounds
Diagnostic isolation tester
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