I setup an EVO-START2 with an iDataStart HCX in a 2016 Kia Sorento (push-start) but since there's a T-harness the only manual connection required for the entire install is from the EVO-START2 (yellow igition wire).
The T-Harness doesn't connect to an igition wire in the vehicle, so I can't just run the EVO-START2 yellow ignition wire to the HCX or T-harness. Instead I have to connect the yellow ignition wire to a longer wire that can reach the driver kick panel, and tap a connector there.
I tried setting up the EVO-START2 without the yellow ignition wire and could not get validation (purple LED flashing) to happen, which didn't surprise me too much. I temporarily connected the yellow igition wire by pushing it into the back of the relevant pin/connector in the driver kick panel. This got me past validation and everything worked.
To finish the install I needed a longer wire, so I left the vehicle to find a wire and to show my wife the app. We started and stopped the vehicle, locked/unlocked doors, etc. It all worked (we could hear the vehicle from within the house and the app confirmed every command).
To my surprise, when I got back to the vehicle, the yellow wire had fallen out of the connector it was temporarily pushed into. This caused me to wonder if it was disconnected the whole time I was away, and so I tested functionality without it.
Everything seems to work without that wire (except for the one-time validation step). As a secondary test I tried starting the vehicle using OEM fob and watching to see if the app reported that the vehicle was on. It did and showed the countdown timer and temperature etc. I can't find anything not working.
So this leads me to the question in the title - do I actually need this wire? Everything presumably is working through data without it. If I don't connect it then I have a 100% plug-and-play installation, which is ideal.