Safety first: Communication faults are usually not immediately dangerous but can indicate wiring issues.

Try another vehicle: Connect a different Audi EV or another compatible EV. If E11 only occurs with one vehicle, the issue may be with that vehicle’s communication module.
Inspect cable and connector: Check the Type 2 plug and cable for damage, especially around the control pilot (CP) pin. Replace the cable if any damage is found.
Reduce electrical noise: Ensure that no heavy inductive loads (e.g., large motors, welders) are sharing the same circuit or are switched on/off during charging attempts.
Update firmware: Use the Audi app or service interface to check for charger firmware updates. Install any available updates, then retry charging.
Professional diagnostics: A technician can check the PLC modem status via the service port and verify CP signal integrity with an oscilloscope. Replace the main control board if the PLC module is defective.

If communication errors persist across multiple vehicles and cables, board-level replacement is usually required.

Audi wallbox displays E11 and the app reports ‘Communication error with vehicle’; charging does not start.

Possible Causes