TCS multi symptom problem,need help

This is a multi symptom problem with a 2003 Venture van.
1.) intermittant "traction active" light going on momentarily at dry times, and making a grinding noise (my previous 2000 Venture never made any noise.)
2.)what may have caused a recent horrible grinding noise and vibration while trying to brake? I felt like I was trying to stop a sled in snow with a shovel as a brake! Felt grinding vibration on brake pedal right up through my body.
The history is at approx 30,000 miles the traction control light would just go on momentarily -a yellow light "traction active" however it did it while backing out on Dry pavement and wheel turned, other times on a slight incline it would come on, and upon accleration make a horrible grinding noise.
Now the other day on slick snow conditions I went to brake -and scare of my life, no stopping--upon braking a horrible grinding noise and vibration from brake pedal right through my body -eventual stoppage by sheer length of no acceleration thank goodness. Then while testing in a dry parking lot no braking trouble.
Anyone with ideas

Milage of course is 36,100! 100 over warranty that I will address, as I have brought to dealer who could never replicate problem.
Thanks to all from a newbie first post.