How do I wire a phone/AUX input into a car stereo?
Pretty much most CD changer options on factory radios require digital communication to enable. SCL and SDA typically refer to I2C clock and data lines. Sdvc is possible voice control, swc is likely to be the wheel control. The middle eight pins are the four speaker outputs. Diag is diagnosis, mrq is likely to be an interrupt input? A ground could mean aux or analog ground. 

That said, the picture of the connection harness shows its not wired for the voice option. Analog or aux ground, tel mute and tel aux have no contacts.  The radio may support it but the wiring for it does not