It has been somewhat frustrating having to deal with this. When it's data it is very hard to troubleshoot. I basically have to call tech support and I have to verify connections. Once that is done it is basically "oh well guess there is a variation on that one we haven't seen, sorry."
With resistance based I could always go to the clock spring and use a meter to find my wire or wires. Then use manual programming to get it working if the aswc or pac instructions weren't accurate.
I think that the data based controls are why when you go from volume to track you have to wait a little bit before the oem radio will respond to the new input. Same thing happens when you change the radio. There is still the required pause between going from volume to track. I haven't seen this on anything other than the new GMs. I have had some customers say that the OEM unit didn't do that after we have installed an aftermarket but we have 2 newer GMs in the parking lot of the shop and can show that the OEM responds the same.
I am going on 16 years of professional installation and each year things get tougher and we are losing more and more analog controls. Almost everything has gone data to data so when things dont work it is frustrating and you become a part swapper since trouble shooting is limited to checking power, ground, and continuity on data connections.
Sent from my SM-G955U using Tapatalk