I have a similiar issue were the Service 4wd light would come on and you couldn't use the switch to switch to 4Wd. It was a module. I will look throught my dealer receipt to see what it was. Of course the dealer didnt find what the problem was until I went into my extended warranty and had to pay the $100 deductible. Will it was still under the 3/36 they kept saying they couldn't find anything wrong.
