My 08 Q7 doesn’t have cold weather package=> no rear heated seats. I heard in the forums that rear seats were prewired with heat elements and all we need is the 4zone AC controller, but I was wrong. I bought the controller with Heated Seat buttons, replaced it and it doesn’t see the temperature sensors. Checked the rear seats, and no sign of any wires for the heat elements. Anyhow, I did remove and replace the controller.
Since there is no wiring, the dial sits at zero even when I turned the knob. The MMI automatically sees the new controller, no need to use VCDS to activate it, it may cause CP (component protection). Since I don’t know where the heat elements wires connected to the controller, I don’t use the new controller at all. For quick retrofit, I bought the carbon fiber heated elements for the back seats.
For coding the VCDS when I get the original heated seat elements installed.