My dishwasher has been working fine for a few years and lately leaves about 2 inches of water in the bottom of the unit when the cycle is completed. Otherwise, it runs fine. Can a liquid drain cleaner be used in the unit? It is a GE Triton Dishwasher
On some machines you can get to the drain pump impeller from the inside - just one Torx screw at the very bottom of the internal sump underneath the filters.
Sometimes crud builds up and stalls the pump - pick it out with tweezers. The impeller blades should rotate freely but with a bit of magnetic resistance.