Audi EV charger shows E04 and the contactor does not close; no charging current flows.

Safety first: The contactor switches high current. Only qualified personnel should open the wallbox and work near it.

• Listen for contactor operation: When starting a charge, you should normally hear a distinct click from inside the charger. If there is no click, the coil may not be energized or is open.
• Visual inspection: With power off and cover removed by a professional, locate the main contactor. Check for burn marks, melted plastic, or signs of overheating on the contactor and surrounding wiring.
• Check control connections: Verify that the low-voltage control wires from the main control board to the contactor coil are firmly seated and undamaged. Reseat any plug-in connectors.
• Coil resistance test: An electrician can measure the contactor coil resistance with a multimeter. An open circuit or very low resistance indicates a failed coil; replace the contactor with an Audi-approved part of the same rating.
• Board driver check: If the contactor tests good but is not being energized, the driver transistor or relay on the main control board may be faulty. Replace the main control board if no control voltage is present when a charge is requested.

Do not attempt to manually force the contactor closed. Replace defective contactors or control boards to restore safe operation.