I have tried to connect my amp/subwoofer to the Front out (red(RIGHT)/white(LEFT)) as well I tried the Back out(red(RIGHT)/white(LEFT)) and Sub out using a Y jack no avail. I get absolutely no sound to the sub from all 3 outputs.

I am not able to get any output from my sub. I believe the sub level is turned off on the unit and I need to find away to turn it on.
I tested my amp and sub in another car the setup worked flawlessly on a pioneer desk.
PS: Other Head units appears to have this functionality not sure why mine does not. Please see attached picture for what I am looking for.
Please advise.