How can I fix my Zanussi 1600 Aquacycle 5.5 kgs washing machine?

My machine a ZWX 1605W, type P6849647, prod no. 914517270/00 - won't finish any cycle from the start. I load as normal and select a program ie Cotton at 40 degrees, the machine fills and starts to wash, after washing for a short time it goes into pause mode and won't continue. If I switch it off and back on I can manually skip the wash sequence to rince where it does the same, then I switch off and back on and skip the rinse sequence when it then completes to the end.