Has anyone connected his or her empeg to the steering wheel remote of a modern Chrysler or does anyone have a suitable schematic to do so?

I am lucky enough to have a tuner module and want to connect directly, ideally without using any interface. I put a volt and ohmmeter on the wire, which I think, comes from the steering wheel but nothing registered when pushing the buttons. A search of the web shows PAC have an interface to go to IR and I found another schematic which suggested Chrysler use a digital interface instead of a resistors like Sony. This seems a bit over the top for a car manufacture but I would guess its possible they transmit IR signals over a cable like Sony’s S-Link interface.

Can anyone clarify or provide help?

The vehicle is a modern Jeep Grand Cherokee if that makes a difference.