I had a problem with my switch not being illuminated and subsequently not engaging 4wd. I took it to the dealership and was told that my transfer case module was not functioning. Therefore, I bought a TCM from a junk yard and replaced it myself. It appeared that everything was going to be okay as magically the indicator lights began working. However, when I switch it to 4 HI or LO the yellow light blinks for a few seconds and then goes back to the 2WD light being illuminated. It has been well in excess of a year since the 4wd has been engaged. I do not know if something is wrong with the shift motor or possibly need to check / replace transfer case fluid. PLEASE HELP!! THANKS!!

 

First off, sorry to hear about the troubles. Secondly, model/year/eng/miles/trans

 

Did you replace the TCM or the TCCM? The TCCM is under the dash and the TCM is under the hood.