Smart Trak Problem

I recently bought a 2000 Bravada with 123K on it as I needed another vehicle and didn't want to spring for a new one at this time. It was really clean and seemed to perform well. I took it out of state over the holiday's and it seemed to do well, except I would notice a vibration when I went round a curve on the interstate and had to turn the wheel to the right. It went away as soon as I straightened out the wheel and it does not do it when I turn left. It does not seem to do it all the time. Well I'm back home after the holidays and have just been driving it locally. Everythings been fine until we got about 6" of snow the other day. It doesn't seem like I'm getting any traction at all from the front wheels and maybe only one of the back ones. I was getting stuck like you wouldn't believe. While the wheels were spinning, the service AWD light came on, and stayed on until I shut off the vehicle and then turned it on again, which reset it. I don't know much about these drive systems, so anybody help me out with this? I'm beginning to regret selling my Yukon Denali SUV which had real AWD and would just tear through the snow.

Could be the encoder motor on the transfer not operating or a shoot clutch pack in the transfer - GM went to a new blue syn fluid (not red Dexron) due to failing cases and cold makes them worse so get that case fluid changed first. Dealer ony GM#12378508 at $7 each takes 2 per change and they recommend changing, driving 100 miles, change again if problem still there. Also see if front diff fluid full and they also recommend syn gear oil in that in cold climates.

I recently bought a 2000 Bravada with 123K on it as I needed another vehicle and didn't want to spring for a new one at this time. It was really clean and seemed to perform well. I took it out of state over the holiday's and it seemed to do well, except I would notice a vibration when I went round a curve on the interstate and had to turn the wheel to the right. It went away as soon as I straightened out the wheel and it does not do it when I turn left. It does not seem to do it all the time. Well I'm back home after the holidays and have just been driving it locally. Everythings been fine until we got about 6" of snow the other day. It doesn't seem like I'm getting any traction at all from the front wheels and maybe only one of the back ones. I was getting stuck like you wouldn't believe. While the wheels were spinning, the service AWD light came on, and stayed on until I shut off the vehicle and then turned it on again, which reset it. I don't know much about these drive systems, so anybody help me out with this? I'm beginning to regret selling my Yukon Denali SUV which had real AWD and would just tear through the snow.

Welcome on your first post on AF.
As Muddog stated They need proper service with the proper fluid.
If the tag on the back of transfer case says 136 it is a PCM controlled unit.
Controlled by the transfer case control module {ATCM} and linked to the engine and ABS computers.
Do you have any check engine or transmission or transfer case lights or abs lights on or any shift lights on or blinking?
Check all fuses and power and wiring and all vacuum line if it has a front axel vacuum lock in.
Also you will need to get it on a full transmission and engine and abs capable scanner to see what is going on.