Pots and Pans should go on the top rack of the dishwasher.
However if the pots and pans are flat ones then they should be placed on the bottom of the dishwasher and tucked along the sides and back of the rack of the dishwasher.
Pots and pans should also be angled upside down so they get cleaner and the soap and water drains off of them.
Also make sure to clean off any hard food debris or other larger grime or stuck on food so that it does not come off in the dishwasher and clog the dishwasher drain.
If you don't clean or scrape off the large food particles then the food particles will clog the drain and make the dishwasher not clean or drain as well.
But if the pots and pans are just a little dirty and have grease on them then wipe the grease off or oil off and then place them in the dishwasher.