F 51 appears on most of the cycles. Only the 'whitest whites' cycle seems to be unaffected. The machine stops completely. If I push the stop button, the error message goes away. If I hit the start button the machine will start again but immediately goes back into trouble. I then have to cancel the cycle, let it drain, and start the 'rinse, spin, drain cycle', but now this cycle is getting the error code. So in effect I can't run a complete wash cycle, I can't rinse and spin the soap out of the clothes, so the load is left somewhat clean, somewhat rinsed, and sopping wet.Our washer was purchased July 28, 2007. The trouble started shortly after the one year warranty expired. I researched the error code online and have determined that the mother board needs to be replaced. This will cost between $200-400, for a machine that has been in use for less than two years. This week we received a form letter from Sears advising us that if the serial number on our washer fell within a certain range, the mother board would be upgraded at no cost to us. Our machine has a serial number that is higher (CU instead of the CS-CT range) which indicates to me that it was manufactured after the target machines. This means that Sears knows about the problems but as yet is unwilling to fix our machine at no cost to us. They have the serial number of our machine on file. Why did they send the letter to us knowing that our machine is out of the target range? Do I have to pay to get my machine fixed while older machines get a free upgrade? we will be contacting Sears to see if they are willing to rectify the matter. The washer was highly rated on Consumer Reports buts it appears the model is a lemon.