im not sure if i wired the illumination (-) ground or not since the pioneer side only had the illumination wire.
you can use the HU bracket screw for ground if more convenient. just use your volt meter to find your ground.
yah, the acc (red) wire goes to switched 12v on the pioneer.
the pioneer's blue/white remote wire triggers your optional sub if you have one. it just sends a switched 12v. the car has an antenna booster which requires 12v switched power.