Four Wheel Drive Problems

I had just bought an 05 silverado 1500 today from someone on craigslist and I made the mistake to not see if the 4wd is working properly. I brought the truck into a little field covered in snow and put it in 4wd. The All-wheel Drive Disabled light came on and i apparently have a malfunction in the system. The truck did move but it felt staggered or choppy if you know what i mean. Does anyone have any advice or knowledge on this? Thanks

I had just bought an 05 silverado 1500 today from someone on craigslist and I made the mistake to not see if the 4wd is working properly. I brought the truck into a little field covered in snow and put it in 4wd. The All-wheel Drive Disabled light came on and i apparently have a malfunction in the system. The truck did move but it felt staggered or choppy if you know what i mean. Does anyone have any advice or knowledge on this? Thanks

first check all fluids in the drive train. then if fluid is good get the DTC codes of the drive train. this requires a scanner that has this ability. then post here.

if the transfer case fluid is black and not blue then the transfer case is N/G.