A Model Number might help others help you.

The unit does not pump water in. It simply opens a valve.

Remove the kick plate.
Valve is usually on the left hand side.
Remove the wires from the valve and measure it for continuity use a 2 Kohm scale.
If it is an open (infinite ohms) then it is shot.
If OK.
Check the over fill switch, also on the left hand side.
Float may be stuck in the up position.
The switch should be closed (0 ohms).
If OK
Reconnect the float switch
Place the timer at the start of a cycle (fill)
Measure for volts across the valves wires, should get 120 volts with door closed
If no voltage then the timer may be shot.
If OK
Either the valve is shot or the filter screen on it's input side is clogged with gunk.
Shut the water supply off.
Remove the valve and check/clean the screen.
Do not remove the screen. It is there to keep crud out of the valve which might hold the valve open and cause a flood.
If screen is clean probably the valve is shot