I have a 2000 Astro with AWD. This the 3rd one I've owned, and love them to death.
Why GM quit making them is beyond me.
The reason I'm writing here, is because I have not read anywhere, or has had anyone tell me, how the AWD works.
I know that when a rear tire loses traction, the awd kicks in. I've felt it happen many a times, and was glad for it. It has also allowed me to go through stuff, that I know rear wheel drive alone wouldn't let me go.
I've never had any trouble with it, but now with my last van, I'm not sure.
I've had the check awd light come on at times, but when I shut the van off, it will not re light up. I've heard the buzzing noise that comes from somewhere under the dash, or engine compartment, that lets me know the awd light will be coming on. I do know that there is an electric motor that kicks it into and out of awd when called for.
What I don't know, is at what speeds does the awd work? Does it disengage at hiway speeds, even if there may be a wheel slipping?
I used to roll down the window, and watch the right front wheel spin in snow, doing it once in a while to be sure it was working.
Yesterday, out to my folks farm, I drove down a hill that I never had trouble with before (my other 2 vans), and when I was backing up, I noticed the front wheel not spinning, like the rear wheels.
Then, when going back up the hill, I stepped on the gas, to see if the front end kicked in. The front wheel did not spin, and the check awd light came on. Thank goodness, for having excellent all season tires, or I would have been stuck.
I know everyone is going to say the actuator motor for the awd is bad, but with the expense of it, I want to be damn sure.
If the awd is not working, maybe that is why I'm getting such good mileage, compared to my previous 2.
I have just installed a G-Force performance chip to it, and hope to see the increased mpg that it boasts (4-7 mpg).
The 60 extra ponies are just an added bonus, along with the increase in torque too.
I appreciate any and all who can answer my questions, and read the posts, to see if I can offer advice on anything I've come across.
LONG LIVE MY ASTRO!

 

I have a 2001 AWD LT .... lots of engine problems - $10,000 worth. Still trying to save it (pictured) ... like new inside and sharp blue exterior. The 4-wheel drive NEVER disengages. There is no lever, switch or button that renders the front gear box independent from the engine power. I have not had trouble with this aspect of mine, but as I understand it all 4 wheels do have the old "posi-traction" slip arrangement. What spins freely or under power has to do with the weight distribution and traction sensors. Any "good" GM service mgr. should be able to diagnose the warning code .... and like with brake sensors, may not stay on after the start-up sequence. good luck!

 

Really, 60 extra hp and 4-7mpg more gains.. Can you do a dyno video please? I really am looking for a way to add some hp and gain a few mpg. Also how much did that chip cost?