I am trying to figure it out for a project i am working on. is it analogue or digital or something completely different.

If you mean the AV1/AV2 inputs, it's analog.

should have been more clear sorry. the input for the wired remote. like steering wheel adapter

Well, technically it's analog (certain voltage level == specific button press). It's been discussed quite a bit in the F-Series Hacks forum, this thread in particular is very useful...

thank you very much I am changing out my radio for a carputer and this is one of the last things i need to figure out.

Connect2 is great for giving no information but since the F90BT uses a resistor type input for the control that has to be what the output is of the controller. i might have to pull it and test it.