Won't you know, almost mid-April and we get hit with a snow storm!!! And won't you know it my 4X4 will not engage!! My luck!! On the way home from work I tried to put her in 4wd auto well the light just flashed and was still in 2wd. So I thought I'll try 4hi same thing. Next I try 4low and it engaged (but the light was still flashing) so I take it easy in 4low al the way home. Well I get home and try 4hi and 4auto again nothing, so i try 4hi and this time nothing. So no 4wd at all now!! So it disconnected the battery for 20min and tried again nothing. See the lights flash or it jumps back to 2wd. I can her the TCCM (transfer case control module) clicking and it sounds like the transfer case is shifting (feel a little movement) but it seems like its not grabbing. I'm think it could be the transfer case motor most likely or the TCCM?

 

Back in december our blazer wouldn't go into 4HI or 4LO automatically.. our solution was to do it manually.. shift into neutral, and press the 4LO or 4HI.. maybe that'll give you some luck.. i ran out to the car to get the book .. here ya go