The PE fault code is signaled by the fill level sensor. It is a device, which is activated by pressure and connected to the tub with a sealed air tube. The sensor responds to the changing pressure in the tube as water begins to fill the tub. Once the water reaches the level specified on the dial, the pressure sensor signals the system to stop the filling process.
The error occurs when the air tube get plugged or the sensor it bad. The sensor is located right under the top cover, near the tub’s top. Check the air tube by blowing through it. Not unlikely, it is blocked by a piece of debris. Check the filter in the tube for blocks and clean it if necessary.