legacycentral bbs

Hey guys, I'm swapping a 2.2T into my Impreza wagon and I need some help with my ecu pinouts.

I have everything I need for the swap (the donor car is in my driveway). I've been reviewing ECU pinout diagrams and have been trying to figure out the best way to merge my 1.8 harness to the 2.2T ECU. There are more wires for the 2.2 ECU, so I know I have to add some wires from the Legacy harness, but there are a few that seem to cross over that I'm not sure about. I've compiled a spreadsheet with the 2.2ECU and the Pinouts and the corresponding 1.8 ECU pinout location. You can see how they map up, and where I'm not sure what to do.
Left column is for 2.2T, center is what the wire is for, left is where that maps out in the 1.8, and then I have a notes section. Sorry for the huge pic, I wasn't sure what the best way to post my spreadsheet was.

Anywhere I have ??? I'm not sure what to do.



Thanks in advance for the input. Here are my source ecu pinout files for anyone willing to help:
http://legacycentral.org/library/ECU_Landscape.htm
1.8 ECU Page 1

1.8 ECU Page 2

1.8 ECU Page 3

I'll try to give my comments

TI monitor - don't worry about it
Idle switch - this is tied into the TPS, and if you are using the 2.2T motor & ECU, you will need to wire this in from the TPS to the ECU.
Trouble code output - I don't think you need to worry about this
TPS shield - You will need to add this. This keeps RF interference from messing up the signal from the TPS
Power supply - 12v power from the ignition switch
MAF sensor power supply - The ECU sends 12v to the MAF sensor, you'll need to add a wire going to the MAF sensor if it's not already there....it should be if it was a MAF based engine

Thanks Josh!

Mapping it out was pretty straightforward, but all the different "power supply" connections made no sense.

I'm going to start tracing wires and following them from the ecu to the end of the legacy harness to see where they actually go, and then I can fine the corresponding match in the impreza harness.

I considered yanking out the impreza harness, and replacing it with the legacy one, but I wanted a clean and mostly stock harness, so I figured merging would be the right way to do it.

More swapping of the wire locations to get them to the right pins, but cleaner in the end.

I need to go back over my 1.8 ECU map to see what wires I haven't accounted for. I know there's a bunch of EGR garbage I won't be needing.

I'll be following this on principle, as I might merge a '95 Legacy harness with a 22T ECU within the next year.