I'm trying to find ways to keep the trip computer in the car with an aftermarket head unit.

I briefly looked at the LCD unit and noticed there's a wire harness that comes out of another harness which goes into the radio. Does anyone have a pin out?

I'm wondering if the fuel computer is present somewhere else in the car, ie: the ECU, and the radio simply passes information between the LCD and the ECU...? I mean, there's no way the radio would have access to the fuel information without being able to talk to the ECU.

So my question is: Where is the fuel computer located? Is it really part of the radio or is the radio simply acting like middleware?

I stripped a factory head unit down to just a small circuit board, but it made me realize I still need to figure out how to wire the front radio panel (Ie: all the buttons) so I actually have the "info" button... At least it beats having to stuff the entire radio in your glove box. The circuit board is the width of the radio and about 2-3 CDs thick.