I found this guy's site recently. He has lots of info and a bunch of videos about troubleshooting modern cars. I have learned a lot from the site.
http://ericthecarguy.com/
http://ericthecarguy.com/
Looks like many of the videos were taken down and their youtube channel shut down with violations. Forum is offline. The other sections are pretty good thoughthat looks like a good site but i prefer this one my self..
http://www.auto-repair-help.com/automotive_videos/index.php