BYD Fault Codes & Warnings, Explained in BYD Context
Written and edited by Ethan Cole, Editor-in-Chief · ✓ Technically reviewed by Daniel Wei Chen — Senior Chinese Automotive Diagnostics & Repair Specialist, Sydney · 22 August 2026.
EVs change the fault-code game: much of what matters on a BYD surfaces as dash warnings (“Power Limited”, charging messages) rather than P-codes a cheap reader shows, and BYD’s own control codes are publicly undocumented — we publish the standardised codes we can verify and the documented warning patterns, and we say where the wall is. One rule above all on any BYD: orange cables and everything they touch are dealer-only. No exceptions.
Documented so far
| Code / warning | Standard meaning | BYD context |
|---|---|---|
| P0562 | System voltage low | The code form of the family’s best-documented pattern — 12V bricking on Seal, Sealion 6, Shark 6, Atto 3 |
| P0A80 | “Replace hybrid battery pack” | The scariest-sounding code in the book — and on a BYD, documented causes are sensors and software far more often than cells |
| U0100 | Lost communication with ECM/PCM | Network silence: 12V first, connectors second, panic last |
| “Power Limited” (dash) | — | Documented on the Sealion 7 (software/sensor logic) and Shark 6 (towing SOC management) — two different mechanisms, one yellow banner |
How to read a BYD fault without fooling yourself
- The 12V battery is suspect #1 for almost any electrical weirdness — it boots the computers that run everything else.
- Screenshot the dash (warning text, icons, when it happened) — BYD service centres work from the exact wording.
- A power cycle is legitimate first aid — documented on the Sealion 7’s Power Limited — but a warning that returns after power cycles needs the firmware fix, not another restart.
- Blade battery panic is usually misplaced: LFP chemistry plus the warranty window (see our schedule pages) means cell failure is the rare ending, not the default one.
Code definitions per SAE J2012; BYD context from our per-model problems research. BYD-proprietary codes are not publicly documented and are not guessed at here.
Disclaimer: Information on this page is general guidance only and does not replace the manufacturer’s official documentation or the judgement of a qualified technician. Never open, touch or work on any orange high-voltage component. Fault-code behaviour varies between markets, model years and software versions. Last verified: 22 August 2026.