E009 error; charger reports internal communication fault and may reboot repeatedly.

Safety first: Disconnect power before handling internal wiring.

• Power-cycle: Turn off the breaker for 2–3 minutes, then restore power. Observe if E009 clears temporarily.
• Inspect low-voltage harnesses: With power off, open the charger and check all ribbon cables and plug-in harnesses between the main control board, display board, and communication modules. Reseat connectors firmly.
• Check for moisture or corrosion: Look for signs of condensation or corrosion on low-voltage connectors. Dry and clean as needed; address any enclosure sealing issues.
• Reduce electrical noise: Ensure the charger’s supply circuit is not shared with large inductive loads (e.g., welders, large motors). If it is, consider moving the charger to a dedicated circuit.
• Module replacement: If E009 persists after reseating cables, the display/communication module or main control board may be defective and should be replaced as a matched set per Autel guidelines.