hi! so i've done some reading already on this as the 'service 4wd' light came on, infact thats how i found this forum so when lights on the truck won't shift out of 2wd. turn it off and and back on, no light, it shifts fine. it seems to happen pretty randomly. i read a thread on here about replacing the sensor in the encoder motor which is likely where i will start. i'm hoping the TCCM isn't fried. second question; when the 'service 4wd' light is on, can i pull coded witha typical OBDII scanner? i'm not afraid of pulling stuff apart. i'm no stranger to fixin' vehicles. just everything i'm used to owning has a shifter........ thanks for any thought/input. greatly appreciated!