In most cases this code would indicate that the brew group has not activated the micro switch located at the bottom of the interior wall because of the following reasons.
1.Brew group not located correctly after cleaning.Therefore has not activated switch while rotating through its cycle.
2. Reducer motor pin maybe loose
3.Micro switch has come out of position
4.Electrical connection to micro switch is loose
5.Reducer motor is not being held in position correctly and is loose because screws are loose or interior wall is damaged .You will need to remove back of machine and examine carefully to reveal damage and or tighten screws .
Please insure you turn the power off as electronics in the rear will still be live even if the front key has been removed and the door is open.