Audi wallbox displays E15 and the app reports ‘Load management error’ or ‘Backend communication fault’ in installations with dynamic load management.

Safety first: Work on meter wiring and communication lines should be done with power off where possible.

• Check system topology: Confirm that the external meter and any other wallboxes are wired according to Audi’s load management diagram, including correct bus termination.
• Inspect communication cable: Examine the RS-485/Modbus cable for cuts, kinks, or loose terminals at both the meter and the wallbox. Tighten terminals and replace damaged cable.
• Verify meter settings: Ensure the external meter is powered, configured with the correct address, baud rate, and protocol as required by the Audi charger.
• Single-wallbox test: Temporarily disable load management or disconnect other wallboxes to see if E15 clears when operating standalone.
• Controller diagnostics: A technician can use the service interface to check load management controller status. If internal faults are reported, replace the main control board or dedicated load management module.

Do not bypass load management protections in multi-charger installations; correct communication issues or replace faulty components.