My bosch Ltd edition, auto option dishwasher(SGS56A72GB/17) is not working?

Bosch Limited edition autoption dishwasher, SGS56A72GB/17 type S9VT1B is not working properly. I begins the wash ok but towards the end of the cycle it just seems to be doing nothing but making a low humming noise, with a small 'trickle' of water coming out of the arms which are not spinning. On the auto wash it does this with 32 mins left to run, and on the quick wash it is at 17 mins left. sometimes it works after using the reset buttons, but is getting steadily worse.