My guess it's the process of activating clutch engagement inside a defective coupling. The coupler clutch system is trying to engage the input driveshaft to an internally torn apart output shaft flange/spline. It could be grinding the internals together causing the jerking and banging. Killing the clutch activation (removing fuse) eliminates any internal coupler attempts to join the input/output shafts together. " Remember I said my guess nothing proven"I drive mine like that (switch installed) regularly, as a preventive measure: I do not have the problem. ESC and ABS are still alive. NO problem other than the "slip" light on the instrument panel, that disappears when I turn AWD back ON. FOr the rest, it becomes a FWD, period.
However, the condition you..and others...have described in a similar way, makes me puzzled: if pulling the fuse clears the problem, it means the coupler itself, I mean the clutch components, are then electrically de-energized and act accordingly. SO the problem is not the clutch itself, but the elements that keep it energized when it should not: OK they are "part of" the coupler system (pressure sensor, hydraulic pump motor, ....?) and are part of and replaced with the replacement of the whole "coupler" , thus clearing the problem...for a while, it seems from reports that the problem comes again later. IF my question here proves true, it could mean that my "coupler saving" solution might not save the problem in the long run (unlesss it also saves the crappy electronics) . Fact is, KIA (Hyundai) DOES have a problem, since it repeats itself systematically, maybe not for everyone, but in the same way for all those who are plagued with it. ANd their only admission that there is a problem is that they replace the coupler.. they correct the result, not the cause.