steering wheel controls on porche cayenne

Im installing a peripheral steering wheel adapter on a porche cayenne to a kenwood deck. The radio is installed and fine,I called peripheral and asked them and they just said good luck. So i checked behind radio and what i get is varying voltages on the control wire. Im looking at steering column and located some wires there but i wonder if some of those wires are multiplex . Im going to check those wires today with a meter ,but if someone has some input  i would appreciate it . Thanks.