2005 GMC TRUCK WILL NOT ENGAGE INTO FOUR WHEEL DRIVE

SOURCE: i have a 1999 gmc

If you have front end problems like an pitman arm or idle arm needs to be replaced, it may not got into 4 wheel drive. Go to the nearest muffler shop or mechanic to have them lift up your truck to see if something needs to be replaced.

SOURCE: four wheel won't engage

Theres a vacume dash pot under the battery box. It pulls a cable that engages the front diff. Put the vacume line and you'll have lights and four wheel drive. (it happened to my blazzer)

SOURCE: 4x4 in working

try reversing six to eight feet after shifting into 4WD. PLEASE RATE MY ANSWER.

SOURCE: 4x4 will not engage in 96 gmc yukon

I just fixed a friend of mines 96 yukon...shift to neutral press 4H and u can hear the actuator make noise (we even replaced it with a new one his idea and the same thing happen as old one), so as he hit the switch for 4H i layed under it (on 4 jack stands) and I could hear the motor on the transfer case make a loud noise (well thats working) and before all this I asked him did u check all your fuses (he said guarnteed to be all good) one night it was bothering me so i looked through the owner manual for the yukon and in the fuse box on driver side by the door there are (2) fuse for the 4wheel drive unit,pull one of the fuses good...pulled the other one and it was blown put in a new fuse and it works like brand new..pull fuse for anything that has to do with 4 wheel drive componants,

SOURCE: wont shift back from 4x4 low, to 2x2

I also have a 2002 Envoy. Shifting to and from 4wh and 4wa can be done on the fly but shifting to 4wL has to be done stoped and while in neutral. Try that. Otherwise I'm afraid its a new computer for you. Its located under the left rear seat and you need a loan for one.