I have a 2009 gmc sierra 4x4 with a floor 4x4 shift. I just bought it not to long ago and used 4x4 last week when it snowed when I engaged the 4x4 it kept acting like the brakes were engaging in both drive and reverse and I got this light that looked like the chassis pop up on my dash could anyone give me any advice what this light is and why it seems like the brakes were engaging? First floor shift 4x4.