finalalarm
The first thing I would do is to open the top part of the pump (look at the
pump and motor break down diagram) and check for any foreign objects. Also at the same time you can clean the filter and the rinse arm from the hard water deposits. You can also access the drain impeller for the inspection.
For your references here is the complete break down diagrams for Maytag dishwasher
Model MDB7100AWQ
Good luck.
Gene.