This has occurred on ours - looks to be as a result of the solenoid for the soap release going open circuit confirmed with ohm meter. Presume the coil has burnt out or winding broken inside it but it is sealed. Not serviceable but could be released easily enough if part available and depending on judgement call when to stop throwing bits of cash at it and replace the complete dishwasher after 11 years.
Tony D, December 2013