Kenmore Dishwasher does not wash

[SIZE=3]My DW made grinding sounds during the wash cycle for a number of loads. Then it quit making noise and quit washing. Now it fills with water, heats the water and drains the water with no washing action (arms do not turn). It does make short humming noises when it is trying to change cycles. Is this a wash pump problem? All the lights on the control panel work normally. Your help is greatly appreciated.[/SIZE]
[SIZE=3]Erwin[/SIZE]