Could be the solenoid valve controlling the rinse water.
Without the water input the programme will stall.
Easily replaced. It is probably a twin solenoid ie, one will be for cold fill the other will be the rinse.
To prove the point try switching the wiring over between the two. If the machine refuses to fill you'll know for sure.
Try www.espares.co.uk and click on the Advice centre and look for the video to show you how to change the solenoids. They also sell the parts
GB in Wales
February 2013