BYD P1A0400
BIC3 working abnormal
Quick answer
P1A0400 is a BYD HV-battery diagnostic trouble code meaning “BIC3 working abnormal.”
This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.
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1. What does P1A0400 mean?
P1A0400 is a BYD HV-battery diagnostic trouble code meaning “BIC3 working abnormal.”
2. Technical explanation
Verified technical-manual index evidence identifies P1A0400 as “BIC3 working abnormal” within the HV battery system. The supplied evidence does not define BIC3 further, describe the fault-monitoring criteria, or provide a diagnostic or repair procedure.
3. What system is affected?
HV battery
4. How serious is this code?
Unknown. Severity is not yet established by verified evidence.
5. Symptoms you may notice
- Not yet established by verified evidence.
6. Possible causes
- A BIC3 working abnormal condition is identified by the code definition.
- Underlying causes are not yet established by verified evidence.
7. Can I still drive the vehicle?
Unknown. Whether the vehicle can be driven with P1A0400 is not yet established by verified evidence.
8. Can I charge the vehicle?
Unknown. Whether the vehicle can be charged with P1A0400 is not yet established by verified evidence.
9. What you can safely do
- Arrange diagnosis by a qualified BYD service provider or appropriately trained EV technician.
- Do not attempt high-voltage battery repair based on this code alone.
10. Step-by-step troubleshooting
- Use suitable diagnostic equipment to confirm P1A0400 and review the complete vehicle fault record.
- Further troubleshooting steps are not yet established by verified evidence.
11. When to contact service
Service requirement is unknown in the supplied evidence. Because this code is assigned to the HV battery system, obtain qualified EV service diagnosis rather than attempting high-voltage battery work.
12. What the service center may check
- Confirm the presence and status of P1A0400 with suitable diagnostic equipment.
- Review complete diagnostic records for additional information. Additional specific checks are not yet established by verified evidence.
13. Possible repair or resolution
- Not yet established by verified evidence.
14. Affected vehicles
- BYD ATTO 3 · 2022–2026 · GLOBAL
- BYD DOLPHIN · 2021–2026 · GLOBAL
- BYD HAN · 2023 · GLOBAL
15. Related TSBs / service bulletins
- No TSB or service-bulletin information was supplied as verified evidence.
16. Recall information
- No recall information was supplied as verified evidence.
17. Official manufacturer information
Verified sources: OBDTotal technical manual index, “BYD ATTO 3 diagnostic evidence,” locator: ATTO 3 / Yuan Plus (SC2E) / P1A0400; 17VIN technical manual index, “BYD DOLPHIN diagnostic evidence,” locator: DOLPHIN / 2021 family / P1A0400; and 17VIN technical manual index, “BYD HAN diagnostic evidence,” locator: HAN / 2023 Champion/Supreme family / P1A0400. Each source states: “BIC3 working abnormal.”
- 17VIN technical manual index: BYD DOLPHIN diagnostic evidence · technical_manual
- 17VIN technical manual index: BYD HAN diagnostic evidence · technical_manual
- OBDTotal technical manual index: BYD ATTO 3 diagnostic evidence · technical_manual
19. Frequently asked questions
What does BYD code P1A0400 mean?
It means “BIC3 working abnormal” in the HV battery system.
Which vehicles are supported by the supplied evidence?
BYD ATTO 3 model years 2022–2026 globally, BYD DOLPHIN model years 2021–2026 globally, and BYD HAN model year 2023 globally.
Can I drive or charge with P1A0400?
Driveability and charging suitability are not yet established by verified evidence.