Bosch SRS8422GB/08 FD8112 slimline dishwasher. Called out for poor wash. Changed heat exchanger as diverter thingy jammed, hence no water to lower spray arm. Called back 4 weeks later for poor wash & whiring noise. Diverter drive motor constantly energised throughout wash cycle & continued running after programme finished, the only way to stop it was to switch off at the plug. No other faults found so changed the heat exchanger again but same problem. I`m now thinking maybe a new control module is required, can anyone confirm or advise ❓