2001 blazer 4wdrive problem

01 blazer zr2 already replaced transfer case control module (one of the pins had corroded off inside the plug) 4wd still not working right though and can't communicate with body control module no other apparent problems other than 4wd. seems stuck in 4lo but if you turn the truck off then start it back up it will shift into 2 hi but when it sits for a bit or you start to drive it it jumps back into 4 lo. then it won't switch to anything until you turn it off and start it back up. I think it has to do with the bcm but i'm not sure. any ideas?

Hi,
I also have a 2001 blazer (trailblazer) I had the same problem with my 4wd I brought it back to the dealer and they fixed it for free cause you have 100k mile warranty on drive train. It was a sensor in the rear axel for mine. They had to take the axel off and replace the sensor. I have had no problem since and I use my 4wd a lot.

01 blazer zr2 already replaced transfer case control module (one of the pins had corroded off inside the plug) 4wd still not working right though and can't communicate with body control module no other apparent problems other than 4wd. seems stuck in 4lo but if you turn the truck off then start it back up it will shift into 2 hi but when it sits for a bit or you start to drive it it jumps back into 4 lo. then it won't switch to anything until you turn it off and start it back up. I think it has to do with the bcm but i'm not sure. any ideas?

Take this to a dealer.

This should be under a warranty or recall.