The F11 and f28 codes are from a communication break in the serial link from the CCU (Central Control Unit) to the MCU (Motor Control Unit)(from the brains to the washer motor controller). Stay with me here!
There are three blue wires that go to the MCU from the CCU. Most of the problems probably occur during the final spin when the machine spins fastest and longest to extract all of the water.
Hence, the most vibrations cause the connectors to shake until there is a break in communication!
Take the top of the machine off (three #20 torx screws on the top back) to gain access into the machine. The CCU is top center back and has the spaghetti of wire going to it. You will see white wires on the far right of the CCU. Then going left they turn to black. The black set (3 wires) left of the row of white wires if for the Door Lock/Unlock. It IS a problem for the F/DL error. It is not making a good connection. Next the blue wire on the LHS of the CCU, last set (back) there are three blue wires. These 3 go to the MCU and are the serial communication lines. Tighten all these wires to make sure they are making good connections. Make sure your machine is level with all the feet on the floor. You do have a 24 month warranty one the machine so call a tech if within that period. To insure that this may be the problem, take a ride and sit on it during the final spin ;-) If it works then you know it's probably the wiring, if it doesn't buck you off first.
You really don't want to replace these parts because the MCU is $230 and the CCU is $175 -- a lot to pay for some loose wires. If you must buy parts, here they are: http://www.repairclinic.com/Shop-For-Par...