Bosch Logixx Dishwasher detergent dispenser ?

I have a problem with the detergent dispenser on my Bosch Logixx srs56a02gb/08 dishwasher and it will not open on any program. I have undertaken the following checks but the problem still persists.

1. I have checked the dispenser actuator for electrical resistance and is OK, but have also replaced with a new one.

2. I have checked the dispenser internally and the mechanical action is OK, i.e. the detergent door opens, and the rinse aid dispenser releases liquid if you manually push the actuator.

3. Have checked all the electrical connections form the dispenser to the control module and are all sound.


I can only conclude that it must be the control module at fault, has anyone got any other ideas what could be the cause of this problem.