I have a 2013 Accord LX. I installed an amp and speakers. I installed a LOC (line Out Converter) tapping into the speaker wires behind the factory head unit, which I kept. When I did this I lost the steering wheel audio controls. All of the other controls on the steering wheel work but those in the upper left. No volume control, no display switching. Phone controls, cruise, etc. all work fine. I took it to the dealership and they couldn't figure it out. Anyone know what might be up? Please help, I am at a loss!

 

I had issues with one of my vehicles that i had to take into the dealership several times before they were able to figure out the problem and fix it. A repair manual, https://www.chiltondiymanuals.com/pr.../productID/135, might help you figure out if something in the wiring is off.