"PE" error:

Water Level Pressure Sensor Error.

1) Verify that the black tube is still connected to the Water Level Sensor at the top of the washer---and to the Air Bell at the bottom of the tub.

2) Remove the black tube from the Water Level Sensor---and blow into tube---to clear a possible blockage. Reconnect and test washer.

3) Water Level Pressure Sensors (6601ER1006E) *rarely* fail.

Source: LG Combo Washer/dryer not drying