Robert, the only cycle which guarantees a prewash is the Pots & Pans cycle and probably the 1-Hour cycle. Smart Wash, Normal, and Light China, the sensor is working full time to determine how full as well as the soil level of the load it's dealing with. Prewashes are eliminated if the soil is fairly light. At one of its pauses in the prewash, if it sees no need for a water change, then the next time the pump turns on, it advances to the main wash period and dispenser opens. Other than heated dry, no other option is available. As for Smart Waash and Normal, options will force the software into a standard default sequence of events. High-Temp will force a prewash, water exachange, and fill for main wash. TurboZone option simmply executes the same sequence as Normal with high-temp, but it also devotes time to the turbozone rotating little sprayers at tehe back being used for periods during the prewwash as well as main wash phases. As noted, Sani-Rinse will also force a prewash because it's going into the same sequence as that with hiih-temp selected, except the final rinse is heated to 155 instead of 140. I've also seen this on the cycle chart buried under the machine. Without options other than heated dry selected, heavy soil sensed in Normal cycle will cause it to select one of two temp options, adjust main wash time, may add additional post wash rinses. Smart Wash offers the widest range of main wash temp set points, based upon soil level sensed, and will also add more time to main wash and may add additional post wash rinses too. Pots & Pans will use maximum amount of water. High temp option or Sani Rinse option on Pots & Pans may increase temperature set during main wash. That's about as flexible as the cycles get. the best option is to leave all options off, unless heated dry, if you want the machine to do what it's designed to do. If you experience some less-than-satisfactory results with Normal and the sensors, then hit high-temp wash, but as stat4ed above, results may not be as good as with Pots & Pans and even with High-temp option selected.
