My 2002 Duramax is having issues... I'm wondering what are the symptoms of the NSBU switch failing?? I've googled it and it seems to be what the issue is, its started with the really hard down shifting then slipping before shifting up, and has a habit of locking into 2nd gear or 1st gear where i have to pull over, shut it off and sit for a minute before it goes back to normal shifting, and now it will go for a little bit and them completely just stop moving, like its in neutral and wont come out. I read that the switch thats on it is the black non waterproof one and being in Alaska with all the crap thats on the roads its messed it up. All the stuff started when i was coming home from Seward and hit a huge pothole that was full of water. Can anyone help me?? Thank you