How can I fix a Zanussi Jetsystem 1200 washing machine displaying error E40?

When we start a wash programme on our Zanussi Jetsystem 1200, it simply clicks 4-5 times and then the display flashes "E40". The manual which came with the machine advises that this error indicates that the door is not closed properly, but this does not seem to be the case. I phoned Zanussi today, who advised that it was most likely an electrical failure of some kind.

Could I have confirmation of what the error actually is and advice on a course of action?

Thanks, Andrew