Ah !! Now it is in proper english I understand. Canbus terminology.
thanks to all for your replay...finally I understand that my car is equiped with a CAN BUS protocol , perhaps finally find an expert of elettric wired of my renault scenic, you can show me where I buy compatible diagnostic equipment for the OBD and if there is a way to use steering wheel controls the radio so it can control the volume of my carpc?
thanks to all