Hiya,
E2 indicates the failure of a temperature sensor in the freezer.
Unfortunately these are foamed in and cannot be changed.
Bosch have modified the main control board for these appliances which bypasses the temperature sensor.
However, for a machine that is 12 years old the replacement board may be rather expensive at £140.84
Hope this helps
Let me know how it goes or if you need more help.
Thanks
Home Appliance Technician
Whitegoods engineer working for a multibranded national company in the UK.
Unfortunately not.
If the sensor is out of circuit the freezer will fail.
At the moment you seem to be having an intermittent problem.
Without the new software on the new board the old one will still be looking for a signal.
Sorry.
Unfortunately there is no work around for this appliance.
It doesn't just cut out the sensor, it also has new software that performs the defrost in a different manner.
Without the new software cutting out the sensor just gives the same E2 fault.