Dishwasher will not start a cycle, display shows E01 shortly after pressing Start.

Safety first: Disconnect the dishwasher from mains power by switching off the circuit breaker and closing the water supply valve before working on it.

Steps to try:

• Power reset: Turn the circuit breaker off for 5–10 minutes, then turn it back on. Try starting a short program to see if the error clears.
• Check power supply: Verify the outlet or junction box has 220–240 V (or local standard) using a multimeter. Loose connections in the terminal block behind the toe-kick can cause control errors.
• Inspect wiring to control: Remove the inner door panel to access the electronic control module (often mounted in a plastic housing at the top of the door). Check the wiring harness connectors for signs of burning, corrosion, or loose pins. Reseat all connectors firmly.
• Look for moisture damage: Inspect the control module and surrounding area for signs of water ingress or condensation. If the control board shows burn marks or corrosion, it must be replaced.
• Replace power module if needed: If power is correct and wiring is intact but E01 persists, the power module / main control board is likely defective. Order the correct Gaggenau-specific control module using the full E-Nr (model) and FD number from the door frame, then replace it following the service manual or have a professional do it.

When to call a technician: If you are not comfortable working with live electrical circuits or the control board, contact an authorized Gaggenau service technician.