I can't Desactived the four wheel drive where is the switch for the four wheel drive, is a GMC YUKON DENALI 2007

No , it's a sealed unit . Hub bearing doesn't cost that much . Wheel bearing assembly replacement 2005 GMC Yukon Denali install remove...

If front park lights are working highly unlikely headlight switch is the issue. Is the vehicle equipped with a trailer towing package and wiring to the rear? I would start there. This vehicle may also have a taillight module located under the vehicle on the passenger rear attached in the wheel well area that goes bad

passenger side rear of engine

If you need further help, I’m available over the phone at https://www.6ya.com/expert/mike_9693b5ad75773352

Go to online store reliable they have repair manuals I am sure you will get the solution. Here's the link
2007 GMC Yukon Workshop Service Repair Manual

The Auto 4 wheel drive is controled by an electronic silinoid. If the silinoid is going bad it will cause it to shift in and out of 4 wheel drive. I hope this helps you out, and if you have any more questions please feel free to ask.

I would venture the guess that your button is broken. The easy fix it to remove it and jimmy rig something manual to activate the function. Then everything will work fine. Additionally, be careful not to let your contraption rub against the actuator under the dash in that area because it could spark while you drive.

Here's a link to a thorough article on the subject which should help you...

http://www.aa1car.com/library/abs_bleeding.htm

http://www.autoblog.com/2007/01/06/detroit-auto-show-gmc-and-jay-z-announce-limited-edition-yukon/

2007 GMC Yukon Denali XL

if i am not mistaking these have the vacuum module on the front differential check it it is probably bad common problem on these trucks from 96 and up if it is the electronic type it could be one of three things the switch on the dash, motor on transfer case, or the electronic module for the 4 wheel drive.