Samsung washing machine 3e fault code

Model wf1124xac/xeu.
Hi.This Samung machine is fitted with a belt and an induction motor and is less than 3 years old.
Problem is 3e code crops up very inconsistantly irrespective of load sizes. I`ve checked the cable to the 3 pin motor plug and all looks ok. 3e is motor tacho but that messures ok. *At the top of the tank at the front is a 6 wired sensor, other than sense (!) what does this sense? Is this a Hall sensor? When the machine goes wrong, though I`ve never actually seen it happen, the drum appears to rock left to right right to left about an inch but will not turn the drum. *This sensor is Partmaster part 3648430pm if you want to have a look at it? Any ideas please.