My wife's envoy is stuck in 4WD low. When she turn's the knob to either AWD, 2WD high, or 2 WD, the light's will blink on them while at the same time the light stays on the 4WD low, and will not change over. Anyone else ever have this problem ?

Welcome to AF, the truck must be standing still and in neutral to shift out of 4W low, are you doing this?