I am confused as to why do you guys waist money on "steering wheel control integration module."???????????
no need to be confused by this, it is actually very simple...
My new stereo had two wires coming out of its harness called "Key 1 and the other Key 2, dedicated for steering wheel control.
this is not the norm... most good quality brands do not have this functionality built in, in fact they are/were mainly designed years ago to be able to have a wired remote hooked up to them years ago (think like an RV, radio in the dash, ande a controller will all the functions in the back) or like sony did, they had a add-on stalk that would mount to the side of your steering column like most wiper or turn signal switches do to add "easier to reach" controls to your car
this was years before cars started adding audio controls on to steering wheels... since all brands don't like sharing their information with their competition, they all use a different system (or a lot of the time, similar system but different codes for each command)
fast forward to the last decade or two when it started becoming popular to have them from the factory, so a few companies started making "translate" modules that would convert the OEM resistance based controls to the configuration that the radio needed to see all using that same port.
again, most name brands are expecting to see their own codes so you still need that module.
however, there are a lot of the low end brands that like Jensen, Pyle, Dual and other cheap brands that (since most are being made for them by some other company) don't/never did offer their own wired remote, they have a learning system that can be hooked up to
resistance based SW controls and then programmed what buttons do what (honestly, this usually only works less than half the time). they usually do support two different resistance lines and a ground reference line in case you need to send ground into the other side of the controls...
HOWEVER, even those super cool radios wont work with a lot of new cars since they are switching to
CAN based SW controls instead of the older resistance based control scheme. in those cars, you still need a SW module that works with can (not all do...) to translate over to a resistance based system, and then they can be learned in.
however, if the last decade and a half of installing has taught me anything, I would rather buy a $50-$70 module and have a great quality head unit, than a loaded with features China special that needs to be replaced every other year (if you're extremely lucky). hell with a lot of the new cars that need pricey modules just to get the radio to function, now have this part built in...
I'm telling you, enjoy these days of $10 wire harnesses, because the times are a changing...