have and 07 5.9 6speed. 273 tc. it wont change from 2wd to 4hi. after playing around for a bit. i discoverd that it will go in 4 low then i can put it in 4 high. but then it wont back to 2 hi with out going into 4 low first. has any one run acrosse this be fore. also no codes and i have tryed the encoder motor.