F11 is a serial communication error. It is recomended to check connections from the motor control unit to the ccu. We are looking for the blue wires that carry info from component to component. The ccu is on top under the cover positioned in back for older machines and front right for new machines. The mcu, motor control unit is behind the kick panel below the door and is front left usually.Again we want to unplug check for dark or crusty connections if not to carefully reseat the connection and not only the blue serial wires but power as well. Remember to first unplug the machine and while you work the machine can reset, 30 minutes is typical.