E90 is a communication error code in AEG washing machines. This error occurs due to a problem with the connections between different parts of the machine.
To fix this error, follow these steps:
1. Unplug your washing machine from the electricity supply.
2. Wait for about 10-15 minutes before plugging it back in. This will reset the machine and can often clear the error code.
3. If the error persists, you might need to check the wiring connections. Make sure the wires are correctly connected and not damaged.
4. If you're not confident about checking the wiring yourself, it's recommended to seek help from a professional.
5. In some cases, the error could be due to a faulty control board. If this is the case, it will need to be replaced. Again, this should be done by a professional.