does it give you the error right away at the beginning of the cycle? or does it wait till it starts trying to agitate?.. run into a few of these that were giving the error on agitate due to the rotor being loose on the drive shaft... when it tried to agitate it wobbled and the rps sensor couldn't make good sense of it..
if it's doing it right away then I'd look at the rps sensor itself.
in the front left of the washer cabinet near the top their should be a packet that has the tech information for your washer.... it should have the specific steps for checking the rps sensor with a meter..