No, actually, looks like (BUS+/BUS-) Pionee's oem signaling that transfers data between devices (CD changer, AMP). What I have done, is I have connected power and audio wires to the aftermarket radio and only power and this BUS to the factory radio and only if I turn on the factory radio the audio comes out.
Seems strange but this is happening in my car.
Thanks,
Sajme