I've looked into the US wiring a little, but haven't yet gotten around to scoping the wires.
On one 8-pin black connector (Connecter i85), it looks like a single wire interface. Pin #8 goes to the body integrated unit. It's probably a low voltage signal to turn on rear defroster, but again, I'm not sure. Rear defrost is the only related device connected to the BIU.
Then, the other connector (i88) has 2 wires (pin7, pin3) which go to the auto AC control module. I'm guessing these are a low-speed serial pair, not CAN since from the wiring diagrams, they don't appear to be twisted, just discrete wires.
My best guess is that one is Tx to send button presses/ encoder pulses to the AC control module, and the other is an Rx to receive display updates from the module.
i85 pin8 is a Green wire (Green? Grey?
i88 pin7 is a White wire.
i88 pin3 is a White wire with Black stripe.
Hope that helps.
Hopefully I can get some probes for the scope I picked up yesterday and start looking at these signals.