Transfer Case DTC codes

Hi All,
I was wondering if anybody knows if there is a way to pull the DTC code from the the Transfer case module without going to dealer. My Service 4wd came on, and then went off, with no apparent trouble to anything else. I know the first owner of the truck has already replaced the 4wd switch on the dash. Don't want to just throw parts at it, and would prefer not to go to stealership if possible.

A full function scanner that also can access bcm codes as well as abs codes is required here.

thanks- I just checked the fluid level, and it was farther down the hole then I could reach with my finger- would this cause the light to come on?

Could have caused some damage that would set a code.