What makes you think it may be bad?
If you Google "appliance repair" there's lots of sites with free parts break downs, FAQ's and on line help.
Your going to need your Model and ser# for anyone to be able to help you on any site.
There is a link to a diagram of your dishwasher. I believe the impeller throws the water into the pump to be pumped out. I have seen the impeller bent and not throwing the water out . That may be what is making the noise in yours.
This is an electric motor and pump....it will receive 110-120 volts AC to operate. Receiving power and the drain lines to and from the pump are ok = new drain pump time. Can hummmm and not run, can break inside, can get clogged inside, can quit dead.