Water pressure is not pushing the spin sprayers up to wash?

My dishwasher "appears" to be working but does not clean anything on the top shelf and just some things on the bottom shelf. It doesn't appear that the water pressure is good enough to push the spin sprayers up and around anymore. The water pressure at home hasn't changed. Is there a pump under the dishwasher that could be broken? The dishwasher isn't any older than 4-5 years. (Whirlpool model)