I have a 05 Buick Rainier awd v6 I just purchased and tried it out in the snow and the awd is not working. I put it on the lift and put it in gear and the rear wheels turn but the front ones aren’t. It’s making a wining noise up front but not turning the front wheels. No dash lights are showing up or no codes are showing up when I hooked up my code reader. What could be causing it not to engage the front wheels? Thanks in advance. It’s a really nice vehicle with only 130k miles so I would like to keep it and fix it if it’s not gonna cost me a arm and leg to fix.