FA error code is a aqua stop error code.
What causes this is water leaking into the base. So pull the washer out and tip it 45 degs backwards and this should allow the water to drain out from the base of the washer. Once the water is out the auqa stop will reset itself and clear the error code.
But if it comes back again then something is leaking in there which you need to find the leak and fix it.
But that's what FA error code means water has leaked into the bottom of the washer.
If you need anymore info just get back to me.