Product review (4 stars): If at first you don't succeed...
My icemaker had quit producing ice in my Kitchenaid refrigerator.  I ordered a replacement icemaker and it worked for several hours overnight and then stopped working.  I visited a blog where an appliance technician said that if you prime the icemaker with water and it still doesn't produce ice then it is faulty, regardless of the sensor.  My new icemaker was apparently faulty as it did not produce ice even after it was primed by adding water manually.  On this same blog, it was suggested that you replace the icemaker and Whirlpool Part Number 2255114: P.C. Board, Receiver at the same time--maybe because they often fail within a couple years of each other, this according to the technician.  I did not want to give up after the first try, and  I figured I'd take the technician's advice and order both the icemaker and the infra red sensor this go around--even though the sensor was passing the troubleshooting test (blinking twice every second then solid if you close the flap).  I'm pleased to report that the refrigerator has been producing ice now for over a week.  Four stars since I had to return the first unit.