My Neff Dishwasher is not draining at end of cycle?

Hello,
I have a Neff Dishwasher S5453X1GB/74 and it's not draining the water out at the end of the cycle.
I have unscrewed the filter and released the impeller. I have also cleared the waste pipe that runs to the sink waste and put loads of cleaner in the dishwasher. The pipes seem to be clear as water goes somewhere during the cycle but backs up at the end.
A few times when I started a cycle the water did not spray out but I could here the drainer or motor? running. I jetted water through the filter which seemed to solve this problem, but it just won't drain out.
Unfortunately for me I cannot pull the dishwasher out as we had a problem with floor levels when fitting the kitchen meaning we had to screed and tile up to it.(Aaaaghhhhh!)
Do you know if there is anyway I can solve this problem from the inside of the washer at all?
Thanks
Elaine