How can I fix my DIPLOMAT dishwasher, Model ADP 8132?

My fully integrated dishwasher - DIPLOMAT ADP8132, starts OK with draining the water, and releasing the dishwashing tablet. However, there is not sufficient water released into the dishwasher. The amount of water is just under the level of the heating element. The heating element works OK. The water inlet valve is OK. The filters have been cleared. The sprayers are clear. For some reason there is not sufficient water in the dishwasher.