Randomly shifting from 2wd to 4wd - 4wd to 2wd - or 2wd to neutral

Discussion in 'GM Powertrain' started by keithl, Nov 26, 2013.

  1. keithl

    keithl New Member

    2003 Chevy Silverado: Shifts from 2wd to 4wd, 4wd to 2wd, and 2wd to neutral at low speed or start up on its own. The problem started two years ago when it switched from 4wd to 2wd. I was able to put it back into 4wd only after I shut the truck off for 10 to 15 minutes. About six months ago it went from 2wd to 4l several times while driving at low speed. It reset on start-up after a prolonged shut down (this always happened during snow or wet conditions). Lately it shifts from 2wd to neutral. This happened once at low speed and once at start up. Again, it would not reset immediately after shutting down the vehicle and restarting. I had to wait for 15 minutes or longer to restart the vehicle for it to reset. Any help would be greatly appreciated. I would like to fix this before I have to call a wrecker to the middle of nowhere because I'm stuck in 2wd and can't get out of the woods. Thanks.
  2. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    Welcome to GMTC! I have moved your thread to the GM power train forum to get you more results. There are 3 things that come to mind while reading your post. The first could be an issue with your dash switch. The second could be your encoder motor on your t-case going out. The third could be a bad connection that is reacting to the wet conditions that you described. I would crawl under the truck and check the connections at the t-case. Pull them apart, spray some electrical contact cleaner on them, let them dry, apply some electrical grease to them and reassembly. That may fix your issue.

Share This Page

Newest Gallery Photos