So here is something I am throwing out there. I purchased a used 2016 Mustang GT and the only thing that bothers me is the crap 4in sync display. I looked and seen the companies producing 8in display SYNC 3 swap outs but wanting $2K for it. So instead I find the OEM 8in display on EBAY in perfect condition and say to myself this will save me a ton of money. So purchased it, purchased the wiring harness from 4d tech, multimedia HUB and everything else I needed. Disconnected battery and made the swap. After the swap was complete and everything put back together I hook battery back up and sit in the car. Not touching any of the peddles to put in accessory mode I push the button and nothing. Push in clutch and push button nothing. I push power button for radio and the 8in display comes to life in all its' beauty and works flawlessly. So I call a dealership and tell them that my push button is no longer working, not even in accessory mode and they say they will not help because of the aftermarket harness. I call 4d tech for help and they won't because I didn't purchase the entire system from them but only the harness. Call a audio shop in town and they don't have the software or hardware to do anything with it. So here I am with a my 2016 Mustang GT with the Sync 3 that it should've always had but my frickin care won't frickin start. I can turn on and off the lights, turn the 4 ways on, lock and unlock it but the frickin push button does not work and have found no parties to help. So I am asking my fellow Mustang owners have you ever heard of such a thing and or do you know how the frick to get my push button working again? I have been told the car may be in a security mode?! Ever hear of this? I guess my only option is to take everything new out and put back the old to hopefully be able to start it and if not at least the Ford Dealer will take it in and fix it. Anybody an give me some help or guidance please do. Thank you!

 

Any chance you accidentally disconnected the start button during your installation process?

 

There is no direct connection to the start button. Only harness plug in to the back of the bezel.

 

I'm gonna take a big old guess, and say what an old mechanic told me one time. "Wiggle them wires boy, see if ya got good connection". Now, that was on an old '63 Chevy, but you never know. Good luck, I can understand how frustration that can be.

 

It isn't just a hardware swap, according to my reading. There's a fair amount of programming required for Sync 3 to work in a 2015-2017 Mustang.

Here on the Mustang 6G website there's an impressive post with all the agonizing details. If I ever do the swap, someone else is doing the work.

 

Did you ever figure this out? Im having the same issue? Thanks

 

Having the same issue here too. Please someone update