F51 error code indicates a MOTOR ROTOR POSITION SENSOR FAILURE (RPS). I purchased the sensor to have on hand when I looked into it. To my surprise I immediately noticed that the bolt holding the rotor was loose and the rotor was not secure. I assumed this caused the error code and after tightening the bolt the problem disappeared. Although I did not use the part ordered, I appreciated the fact that I was able to find the sensor at AppliancePartsPros. Other sources required purchasing the entire kit which was much more expensive and a bigger job if I decided to install the kit. AppliancePartsPros return policy is extremely easy as well!