you have a US spec 4.6iS - DSP is standard on those. Depending on the model of the DSP amp fitted, it can be a digital DSP or an analogue DSP, even though it sounds funny - analogue digital... the reason that your controls work is because one of the wires in the 3-pin connectors is an iBus line, the other two wires are power. the iBus controls the entertainment systems in the car (as well as other aspects)

if connecting the 6-pin connector did not yield the sound, it is obvious that you need to use the coax cable (RG-174 with SMB connector).

that's all...