Switching from 2HI TO AWD TO 4HI on 2004 Chevrolet Trailblazer

When I try and switch from 2hi to awd or 4hi the light flashs on and off then throughs the awd light on in the dash??If I shut the truck off at night and then switch it into awd. When I start it in the morning it will go into awd and work fine.Hopefully someone can help me with this problem so it doesn't cost me alot of money....

Asked by for the 2004 Chevrolet Trailblazer
ck codes and ten switch