Hello the AWD on my 2004 Oldsmobile Bravada isn't working, there previously was a Service AWD light that was on but it went off and I can't get it to go back on. Does anyone have any suggestions or helpful advice on what might be the issue? I live in Michigan and we recently had a snowstorm and the rear wheels would just spin and spin and wouldn't engage the AWD and no Service AWD light would come on. Thanks!

I notice that you haven't reported any strange noises. That'* good, but also makes it so we don't have a direction to go in troubleshooting.

How many miles on your Bravada?

How many miles have you owned it?

Next step: Scan for any stored codes.

I thought AWD was FULL time, not when it wants to? If it was like the Blazers with the Autotrac 4x4, it goes into 4 hi when it detects wheel slip, then its one thing.

Yeah I agree. It should be just a viscous coupling on the in/out shaft and a chain towards the front-drive output. That'* what makes it weird, but I haven't messed with those AWD units too much.

There is no strange noises. It has about 83,000 miles. Ive owned it since about 40,000 miles. On the Bravada the AWD system is called Smarttrak and it kicks on when there is wheel slip. This has just started happening.

*SmartTrac......... and I did check for stored codes with a buddy of mine who is a Mechanic but we couldn't find any codes.

I did check for stored codes with a buddy of mine who is a Mechanic but we couldn't find any codes.[/QUOTE]

https://www.1aauto.com/*/i/1AFWM0001...rm=wOXVXc8F0Bg

I found this online... could it be this part? or something more?

I think your transfer case is a single speed/single mode TC. Which means, you are AWD all the time and require no mode changes.