BYD U029887
Communication with DC/DC failed
Quick answer
BYD DTC U029887 means “Communication with DC/DC failed.” Verified applicability: BYD ATTO 3, model years 2022–2026, Global specification.
This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.
Watch Videos
Relevant videos play here without leaving this diagnostic page.
No sufficiently relevant embeddable video has been accepted for this diagnostic yet.
Videos are supporting material and never override OEM or regulator evidence.
1. What does U029887 mean?
BYD DTC U029887 means “Communication with DC/DC failed.” Verified applicability: BYD ATTO 3, model years 2022–2026, Global specification.
2. Technical explanation
This is a Network-system diagnostic trouble code indicating a failed communication condition involving the DC/DC converter. The supplied verified evidence does not establish the underlying fault mechanism, communication path, or repair procedure.
3. What system is affected?
Network; communication with the DC/DC converter.
4. How serious is this code?
Unknown. The supplied verified evidence does not assign a severity.
5. Symptoms you may notice
- Not yet established by verified evidence.
6. Possible causes
- Not yet established by verified evidence.
7. Can I still drive the vehicle?
Unknown. The supplied verified evidence does not establish whether the vehicle is safe to drive with U029887 present.
8. Can I charge the vehicle?
Unknown. The supplied verified evidence does not establish whether the vehicle is safe to charge with U029887 present.
9. What you can safely do
- Do not attempt high-voltage or DC/DC converter repair procedures based on this code alone.
- Arrange diagnosis by a qualified BYD service provider or EV-qualified technician.
10. Step-by-step troubleshooting
- Record the exact DTC, U029887, and any accompanying diagnostic information for the service provider.
- 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 concerns communication with the DC/DC converter and no verified repair process is provided, professional diagnosis is appropriate.
12. What the service center may check
- 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
15. Related TSBs / service bulletins
- Not yet established by verified evidence.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified source: OBDTotal technical manual index, “BYD ATTO 3 diagnostic evidence,” locator: ATTO 3 / Yuan Plus (SC2E) / U029887. It identifies U029887 as “Communication with DC/DC failed.”
- OBDTotal technical manual index: BYD ATTO 3 diagnostic evidence · technical_manual
19. Frequently asked questions
What does BYD code U029887 mean?
It means “Communication with DC/DC failed.”
Which vehicles are verified as applicable?
BYD ATTO 3 Global vehicles for model years 2022 through 2026.
Can I drive with U029887?
Not yet established by verified evidence.
Can I charge with U029887?
Not yet established by verified evidence.