This is an overview of the Miele dishwasher electronic door lock.
This is an expensive part, close to $300 retail and is a common failure on all models starting the 2000 series machines.
The latch arm is extended and retracted by a high quality DC motor.
The latch arm has cams that activate micro switches to tell the electronic the position of the latch.
The diagrams below are from the service manual.
The Knock 2 Open feature is present on the newest models of Miele dishwasher. It uses vibration sensors built into the power electronic to sense knocks and then use the automatic door latch to open the door.
From Miele’s website:
The perfect solution for handleless design
Not magic, but Miele: Knock2open turns dishwashing into a magical experience while delivering the perfect solution for handleless kitchen designs. “After knocking twice on the front panel of the fully integrated Miele dishwasher, the door opens by about 4 in completely on its own using an ingenious opening mechanism.” A convenience that you can enjoy every day.