Non-PC Plod,
They are actually called "rudder" pedals - yaw is the effect of the control.
Once the engine is running, a FADEC failure, to be honest, is a bit of a non event. Hopefully the other FADEC will have taken over. If it hasn't then oh no - gentle manual thrust and monitor engine instruments for abnormal readings.
If there is a FADEC fail before engine start then you don't start the engine!
BS