Bosch · Dishwashers Series 6
The display shows E:90-01 alternately, indicating that the mains voltage supplied to the appliance is too low. This is not a fault of the dishwasher itself.
Click steps to track your progress.
Contact a qualified electrician.
Have the electrician check the mains voltage and the electrical installation.
Do not attempt to operate the appliance until the voltage issue is resolved by a professional.