help, 2011 yukon won't start

[Summit 700]

My 2011 Yukon won't start, everything powers up as normal but when the key is turned to start position nothing happens. I can hear the fuel pump cycle but get nothing when trying to start it. I get random lights and warnings. Check engine light, theft light and a red warning symbol that looks like this (!). Also messages like, check 4wd system, check traction control system, check trailer brake system. I hear random clicking from under the dash. Also my brake lights won't work, all other lights work. Battery shows 12v. The shift indicator lights up but the line under the selected gear flashes. Any thoughts will help. Thanks
Cory

 

[Goodinblack]

Disconnect the battery and then let it reset

See what happens then

 

[GM Customer Service]

My 2011 Yukon won't start, everything powers up as normal but when the key is turned to start position nothing happens. I can hear the fuel pump cycle but get nothing when trying to start it. I get random lights and warnings. Check engine light, theft light and a red warning symbol that looks like this (!). Also messages like, check 4wd system, check traction control system, check trailer brake system. I hear random clicking from under the dash. Also my brake lights won't work, all other lights work. Battery shows 12v. The shift indicator lights up but the line under the selected gear flashes. Any thoughts will help. Thanks
Cory

Hi Cory,

We regret to hear that your Yukon won't start. I understand you are seeking feedback from fellow forum members in regard to this concern. If you should decide to take your vehicle in to the dealership, we'd be happy to schedule an appointment for you. We're just a PM away if you need us.

Andraya
GM Customer Care

 

[Fink117]

Check fuses

 

[08grey]

Try a jumper pack, battery will show 12v but still be dead.

 

[Summit 700]

I actually did disconnect the battery for a couple hours and I have tried boosting the truck while trying to started it. Any other suggestions? Would the brake switch have anything to do with it because I noticed that my brake lights dont work, all the other lights do work.
Thanks

 

[Goodinblack]

If your dash is a Christmas tree you have computer problems.

 

[khaleej]

Check for trouble codes . It seems to be a communication problem within the computers .
Dtc will bring you much closer .then you can know which module is malfunctioning

 

[Keanen55]

Same thing happened to me 6 months ago. I changed the battery and the problem was solved. I'm going to do a dual battery setup soon! Good luck!

 

[Speck]

Check your grounds. I had a similar issue a few weeks ago where I would lose all power after turning my Yukon off. It would click abruptly and and go dark in the dash, no dome lights, no dash lights, power door locks wouldn't work. Plus, I'd hear popping noises. I'd wait five minutes and everything would come back on, but wouldn't start. Then on third try, it would start like there was no issue. This went on for three days and then I added an extra ground from the battery to fire wall and the issue is gone. I hope this helps or gives ideas. Mine will be going to the dealership if it returns again. Good luck!

Joe