If there is the E2 error code on the display, there is a problem in the pump. Most likely, it has gotten blocked by debris or a foreign object. Remove the filter (located under the bottom dish basket) and check it for debris. Drain water from the dishwasher’s bottom using a tub or bucket. Please, be sure that the bottom is absolutely free from water and waste.
Also, the error may indicate a problem with the electric magnet inlet valve. To check the valve, remove the panel, where the hose enters the dishwasher, and trace it until you reach the valve. Turn off the water supply tap, remove the valve, check its wires and connections. If there are signs of damage, replace the valve with a new one.
Other Samsung dishwasher error code: