My experience is with model SHE4AM15UC/01, but it is likely good for a large range of dishwashers made in the mid/late 2000's. A lot of it is good for about all modern dishwashers. These are hints for things that may make you think something major is wrong, but it is really minor/operator error. It does not mean, for instance, wet dishes after dry, there isn't something else that is major wrong.
1. Wet Dishes after dry
--Remember, this dishwasher dries by super-heating the water during the last rinse cycle instead of running an electric heating element in the bottom. Make sure you do not open the door while it is drying (no audible activity) until the "active" light is out. Best results occur when the remaining heat is left in the dish-washing chamber long enough for all the water to evaporate. Opening the door, during the drying cycle, before the "active" light is out will also not make the "sanitized" light come on at the end.
2. Low water pressure
--There is a metal filter in the bottom of the dishwasher. It does need to be cleaned periodically.I get in the habit of cleaning it at the same time the rinse agent is out. I use an old toothbrush and water to clean it. Every once in awhile, if it is clogged with calcium deposits, an overnight soak in white vinegar will help with that. To access the filter, turn the large round thing in the metal plate with holes and lift up. The filter is a cylinder around the round knob you pulled, slide it off and clean it. Also clean out anything that is in the middle of the round thing you turned and anything that is on the metal plate or in its holes.
3. Detergent left in the detergent holder after washing and/or poor cleaning
--Make sure nothing in the bottom and top rack makes the wash wand in the middle not able to turn. I am in the habit of making sure I turn it before closing the door to start the wash.
--Make sure nothing in the front on both the bottom and top racks will block the wash wand from water being able to hit the front door.
--On the center, bottom of the wash wand, there is a wide bolt thing that holds it together. Sometimes you may roll the top rack in and it will rub against something that was too high on the bottom rack. This could loosen it. If this bolt is loose, water will leak around it and the wand will barely turn and will not have enough water pressure coming out of the wand's nozzles. It tightens counter-clockwise as you look at it from above the top rack (you would reach under the wand to tighten it.) DO NOT OVER-TIGHTEN! Use light hand force to tighten it. The bolt and the wand assembly is plastic and you can easily strip/break it. When the bolt just stops turning, stop turning it! Don't force it, it just needs to be not all the way clockwise (all the way clockwise is the position you could just pull down to take out the wash wand).