Refrigerator displays E04 and may shut down cooling; internal fan may not run or runs erratically.

Safety warning: Unplug the refrigerator or switch off the circuit breaker before accessing the fan area. Moving fan blades can cause injury.

Diagnostic steps:

• 1. Listen for the fan: With the unit powered (before disconnecting), close the door switch with your finger and listen for the evaporator fan running. If silent or noisy, suspect a fan issue.
• 2. Access the evaporator fan: Disconnect power, remove shelves and drawers, then remove the rear interior panel of the affected compartment to expose the evaporator and fan assembly.
• 3. Check for ice buildup: Inspect the fan blades and shroud for ice. If ice is present, carefully defrost with a hair dryer on low. Do not chip ice with sharp tools to avoid damaging the coil.
• 4. Spin the fan by hand: The fan should rotate freely. If it is stiff, noisy, or seized, the motor is likely failing and should be replaced.
• 5. Inspect wiring: Verify the fan connector is fully seated and that wires are not pinched or broken. Repair or replace damaged wiring.
• 6. Test voltage (advanced): With power restored and extreme caution, measure voltage at the fan connector when the fan should be running. If correct voltage is present but the fan does not run, replace the fan motor. If no voltage, the control board or wiring is suspect.
• 7. Replace the fan motor: Remove mounting screws, disconnect the harness, and install a new Gaggenau-compatible evaporator fan motor. Ensure the fan blades are oriented correctly and not rubbing the shroud.

Note: If E04 persists after fan replacement and wiring checks, the main control module may need replacement by an authorized technician.