Charger displays E09 and refuses to charge; often associated with network or app control issues.

Safety first: Network errors do not usually pose electrical danger, but do not open the charger while powered.

• Check local charging: If possible, try starting a charge directly from the charger’s front panel instead of the app. If this works, the issue is network-related.
• Verify router status: Ensure your home router has internet access and that Wi‑Fi signal is strong near the BYD charger.
• Reconnect Wi‑Fi: Use the BYD app or local web interface to re-enter Wi‑Fi credentials and confirm connection status.
• Check OCPP settings: If using a backend, verify server URL, port, and credentials match your operator’s instructions.
• Persistent E09 with good network: The internal communication module may be faulty and require replacement by a technician.