Downgrade back to earlier version of IOS, from IOS 9?

[musiclover77]

I am not sure if I am posting this in the right category or not. I no longer own an IPhone, but my father does. I got sick of the constraints, even when fully jailbroken, and I moved on. My father was recently visiting, and during the visit, we upgraded his phone to IOS 9... dumb move. His main complaint now is that he lost a lot of functionality that he had before, when it comes to integrating his phone with his Truck Stereo system. Before it was set up slick where the art work with display on dash lcd while driving, and he could easily control what track he was listening to etc. This has changed dramatically, and he hates it. I of course, feel terrible for encouraging him to upgrade.

My question is really 2 fold. First, is it possible to downgrade back to an earlier version of IOS where this issue with truck stereo integration will go away. I believe based on what I have read, that the problem began for many starting with IOS 9. Second, can I perform a backup of his contacts, sms, app settings etc in IOS 9, and restore that info back into the phone once he has been downgraded back to earlier IOS version?

Any help will be thanked and much appreciated!!

 

[J. A.]

Welcome to iPhoneForums, musiclover77!

It's not possible to revert to a software version other than 9.1. All you'll be able to do, will be updating the device to iOS 9.1, which is the only version signed by Apple right now.

If you try to install a different version, you'll get an error in iTunes, and you'll not be able to proceed.

Sorry!