2007 yukon denali, when the incorrect sequence is hit to use command start the vehicle won't start at all. Why does this happen?? Now vehicle won't start at all, and it's been three days, in the past this problem has resolved itself within a few hours.

chevy tahoe lift gate not opening - YouTube

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www.youtube.com/watch?v=xU6ybiY3F4I
Sep 1, 2010 - Uploaded by 76bluemoon Back lift gate/glass would not open or release. ... Wow, are you sure? .... known issue with tahoe, suburbans, hummers and othergmc vehicles. ... 2007-2012 Yukon Denali Rear Door Lock Actuator Replacement ... 2004 GMC Yukon XL rear liftgateremoval - Duration: 50:17. by Velvethamma 5,814 views.

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

Might need to adjust rear door latch, or could be bad relay or switch. Try pulling/pushing on rear door while closed to see if you can set this off while sitting still.

if the body control module is seeing any door or hood not completly closed it will not start.

It sounds dumb but make sure you hit the lock button first I had the same problem and that works for me

You probably interrupted the antitheft system. This link explains.

http://vatspasslockpasskeysecurityhelp.yolasite.com/

Sounds like the crash buggered up your door's alignment with the strikers. The best thing to do would be to run it in to a good body shop, or figure out how to align it back with the strikers yourself (Not an easy, nor a fun, job).

It is located under the cup holder in the middle console.

Your sending unit for the guage is part of your fuel pump in the tank. But first try your fuel pump relay, may be working intermittenly when you hit a bump or something. Or possibly a loose wire somewhere along the way. Much less expensive (worth a look).

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

2007 GMC Yukon Denali XL