Symptoms: freezer working fine but refrigerator was warm >60°.
Fault isolation: Narrowed down the faulty componenet to the diffiuser and ordered new diffuser, in the mean time I put a small wooden dowel rod into the diffuser vanes to keep my refrigerator cold.
New problem: after receiving my new diffuser I disconnected power to the appliance and connected the two leads to the diffuser. After plugging the appliance back in the fan behind the freezer back did not kick on. Re-replacing the old diffuser started the fan back up. I performed this several times with the exact same results.
Thanks Gene for replying, the paperwork that came with the part list the following part number 2209751 and the actual diffuser has a sticker that says made in Mexico with a number of 0155A. Hope this helps you to help me.