BYD U029787
Communication with on-board charger failed
Quick answer
BYD DTC U029787 means: Communication with on-board charger failed. It is verified for specified BYD ATTO 3, DOLPHIN, and HAN applications.
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 U029787 mean?
BYD DTC U029787 means: Communication with on-board charger failed. It is verified for specified BYD ATTO 3, DOLPHIN, and HAN applications.
2. Technical explanation
The verified diagnostic meaning of U029787 is a failed communication condition involving the on-board charger. The supplied evidence does not establish the communication path, triggering conditions, root cause, charging behavior, or repair procedure.
3. What system is affected?
HV battery/network; the diagnostic description specifically identifies communication with the on-board charger.
4. How serious is this code?
Unknown. Severity is not established by the verified evidence.
5. Symptoms you may notice
- Communication with on-board charger failed is the verified diagnostic condition.
- Other symptoms are not yet established by verified evidence.
6. Possible causes
- Not yet established by verified evidence.
7. Can I still drive the vehicle?
Unknown. Whether the vehicle can be driven is not established by verified evidence.
8. Can I charge the vehicle?
Unknown. Whether the vehicle can charge is not established by verified evidence.
9. What you can safely do
- Do not attempt high-voltage component diagnosis, disconnection, or repair.
- Arrange professional diagnosis if the code is present or returns after clearing.
10. Step-by-step troubleshooting
- Use appropriate diagnostic equipment to confirm that U029787 is present and record associated diagnostic information.
- Further troubleshooting steps are not yet established by verified evidence.
11. When to contact service
Service requirement is unknown in the supplied evidence. Professional diagnosis is appropriate because this code concerns communication with the on-board charger and the HV battery/network system.
12. What the service center may check
- Confirm U029787 with compatible diagnostic equipment.
- Check for associated diagnostic information. 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 technical service bulletin information was supplied or verified for this diagnostic.
16. Recall information
- No recall information was supplied or verified for this diagnostic.
17. Official manufacturer information
Verified technical-manual-index evidence identifies U029787 as “Communication with on-board charger failed” for listed BYD applications. The supplied sources are OBDTotal technical manual index for ATTO 3 and 17VIN technical manual index for DOLPHIN and HAN.
- 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 U029787 mean?
It means “Communication with on-board charger failed.”
Which vehicles are covered by the verified evidence?
BYD ATTO 3 model years 2022–2026, BYD DOLPHIN model years 2021–2026, and BYD HAN model year 2023, each listed for the GLOBAL region.
Can I drive with U029787?
Not yet established by verified evidence.
Can I charge with U029787?
Not yet established by verified evidence.