Oven door lock will not engage or disengage during pyrolytic self-clean; F9 is displayed.

Safety first: Disconnect power and ensure the oven is cool before working on the door lock. Do not force the door open if the cavity is still hot.

• Access lock assembly: Remove the top cover or front trim above the oven door to access the door lock motor and latch mechanism.
• Visual inspection: Check for bent linkage, broken plastic parts, or foreign objects obstructing the latch.
• Manual operation: With power off, gently move the lock arm by hand to verify it can travel fully. It should move smoothly without binding.
• Microswitch test: Identify the lock position switches and test continuity with a multimeter while manually operating the lock. Replace if they do not change state.
• Motor test: Measure resistance of the lock motor. An open circuit indicates a failed motor. On some models, you can apply low voltage (per service manual) to test movement.
• Replace assembly: If the motor or switches are defective, replace the complete door lock assembly to ensure reliable operation.

Emergency door opening: Many Kuppersbusch models have a manual release accessible from the top or rear; consult the user manual or a technician if the door is stuck closed.