Only problem I've had with mine occurs when I use 4wd. After using, I have to drive around a bit before NT will work again. Ford tech tells me that shift solenoids in the tranny is sticking and takes then a while to shift back fully.
Maybe one of your solenoids is stuck. When it happens, the first check light, when you turn off the ignition, won't even light up.
Also programming for the NTK is in the computer and only a Ford dealer can reprogram
Jerry & Patsy Potter, Taz & Jake Jr.
2000 Winnebago Journey
2006 Ford Explorer 4X4