Bosch Dishwasher makes loud noise and not working

My Bosch Dishwasher is now making a loud noise and it is not working. I have cleaned everything and have replaced the water input valve. The washer has been able to drain when it has pumped water in previously. I have a very loud grinding noise from start to finish. I cannot figure out if it is the drain pump or the circulation pump that is the problem! I don’t want to have to buy both if only one is causing the problem. How do I tell which is causing the problem?