What this usually means
For BYD Atto 3 owners, a no-start or wake-up issue is often the small 12V auxiliary battery, not the main EV battery. Check 12V health first before accepting any high-voltage diagnosis. A proper EV workshop should load-test the 12V battery and scan the low-voltage fault history.
What to ask the workshop before approving repair
- • Show the diagnostic fault codes.
- • Show photo/video proof of the failed part.
- • Give an itemised quote for parts and labour.
- • Explain why cheaper common fixes were ruled out.
- • Use/confirm: EV diagnostic scanner
- • Use/confirm: 12V battery load tester
This is not a final diagnosis. It is a money-saving checklist before you go workshop.