Sound like it wasnt fixed if you needed the warm day to start.

To start diognosing a bad temp sensor.. you have to remove it and place it in differant tempuratures and record the readings. And hope yer doing it right. Or just buy ye dam sensor and swap it. either way if it starts problem fixed.. if it dosent.. well you know your temp sensor is good. DSM stands for something in the world of stick with what works... and the cts IS the most common reason for dsm problems. While yer at it check yer plugs for wetness.