The cold water goes through a mesh screen and often gets clogged. The code usually goes off during the begging of the rinse cycle or at the end. This is when the cold water is most commenly used. YOu have to clean this screen. This is the second time we have had to clean it. The first time with an appliance tech, which cost us close to $100 to do. Now, we will do it ourselves. You just find open up the front, take out the screen when you find it and either clean it with vinegar water or our service tech used muriatic acid.