Realize this is an old thread, but I have a rather old Kenmore Elite HE3t front loader that's been giving me the SUD code. Followed the great direction given here and managed to get the door open, find my tech sheet, and run the diagnostic test. Everything went smooth, right up until the end when it wouldn't unlock again after going through everything else. It locked from the unlocked position just fine at the start of the test, but will not open again at its conclusion.
I assume this means there are two separate solenoids, one distinct one for each function? Haven't messed with the CCU tabs where the harness attaches. The pin/button on the face of where the door closes is not broken and functions fine, although the door does seem to sag somewhat, but as it engages the latch it corrects it attitude and properly meets the button and depresses it. Was all ready to order a new latch until I saw other who had replaced the latch were still having the same issues reappear.