Hello fellow Fit enthusiasts. I'm working on installing a SONY XAV-AX5000 head unit in my wife's 2017 Fit EX with the 6-speed manual. This particular Fit comes equipped from the factory with the 39100-T5R-A81 stereo, which has connections that are different from carlyee's and Bassguitarist1985's stereo pinouts.

Luckily, I don't have to worry about most of this, because I purchased the following adapters from Crutchfield.Thankfully, Crutchfield has a service available where they pre-assemble all of these adapters into a coherent wiring harness which is almost plug-and-play. So, I only have to worry about the steering wheel control adapter and the backup camera harness; the speakers, antenna and USB are all connected and functional.

I have the installation instructions for the steering wheel and backup adapters (here's the instructions for the steering wheel adapter, and here's the one for the backup camera harness). The missing piece for me is which wires in the Fit these have to splice to.

The steering wheel adapter has the following wires and connections which I do not know where to splice/connect to in the Fit (SWC = steering wheel control):The backup camera harness has the following wires and connections which I do not know where to splice/connect to in the Fit:Does anyone know where these need to be connected in the 2017 Fit EX? Or, does anyone know where I could find a wiring diagram for this? Thank you in advance!

 

Here's a quick update:

The jack coming from the steering wheel adapter just plugs into the "remote" port on the stereo. I don't know why I didn't realize this earlier!

I took apart the center console and found the parking brake switch, so that was easy to tap into. I'll post pics and more details about the process when I get to a computer.

The reverse light wires were an absolute nightmare. My first thought was to open up the fuse box and find the backup light fuses. This was easy, but when I removed these fuses, the reverse lights still turned on! I couldn't figure out where these wires were hiding. I was using a clamp meter to check individual wires for current while putting the car into and out of reverse, but most of these wires are bundled very tightly and I did not want to break open the wiring harnesses all over the car, so I did not get very far with this method. Instead, I just ran a wire from the stereo all the way to the reverse light in the back of the car and tapped into the reverse signal there. Then, I tucked the wire under the trim pieces. Easy peasy. Now, the backup camera image is displayed correctly.
Now, with regards to the steering controls, Axxess only has installation instructions specific to the 2016 Fit, not the 2017. I'm going to try this anyway, because the connector in their diagram looked identical to the one I'm working with. I just had to order some extra supplies to make this happen. I will provide an update on this once I make more progress.